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SOLAR HEATING
Domestic Hot Water Space Heat Heat StorageMichael Woods Comm Ave LLC
1
Michael WoodsEngineerConsultant
Comm Ave LLC Green Energy Upgrades Energy Audits System Design Install Solar Geothermal Heat Pump Dual Fuel Residential Systems
2
4 years designing solar heathot water systems
Conducted solar study into seasonal storage
Installed 30-Tube Thermomax Evacuated Tube lsquotest rigrsquo as Domestic Hot Water System 7108
72 reduction in gas consumption
3
o Solar Radiation Basics o Domestic Hot Water Heatingo House Heatingo Solar Site Evaluationo Sizing and Costo Questions
4
1972 National Science Foundation Testimony
ldquoSolar energy is an essentially inexhaustible source potentially capable of meeting a significant portion of the nationrsquos future energy needs with a minimum of adverse environmental consequenceshellipthe most promising of unconventional energy sourcesrdquo1
1-Principles of Solar Engineering Gozwami Kreith Kreider(2000) pg1
5
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Michael WoodsEngineerConsultant
Comm Ave LLC Green Energy Upgrades Energy Audits System Design Install Solar Geothermal Heat Pump Dual Fuel Residential Systems
2
4 years designing solar heathot water systems
Conducted solar study into seasonal storage
Installed 30-Tube Thermomax Evacuated Tube lsquotest rigrsquo as Domestic Hot Water System 7108
72 reduction in gas consumption
3
o Solar Radiation Basics o Domestic Hot Water Heatingo House Heatingo Solar Site Evaluationo Sizing and Costo Questions
4
1972 National Science Foundation Testimony
ldquoSolar energy is an essentially inexhaustible source potentially capable of meeting a significant portion of the nationrsquos future energy needs with a minimum of adverse environmental consequenceshellipthe most promising of unconventional energy sourcesrdquo1
1-Principles of Solar Engineering Gozwami Kreith Kreider(2000) pg1
5
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
4 years designing solar heathot water systems
Conducted solar study into seasonal storage
Installed 30-Tube Thermomax Evacuated Tube lsquotest rigrsquo as Domestic Hot Water System 7108
72 reduction in gas consumption
3
o Solar Radiation Basics o Domestic Hot Water Heatingo House Heatingo Solar Site Evaluationo Sizing and Costo Questions
4
1972 National Science Foundation Testimony
ldquoSolar energy is an essentially inexhaustible source potentially capable of meeting a significant portion of the nationrsquos future energy needs with a minimum of adverse environmental consequenceshellipthe most promising of unconventional energy sourcesrdquo1
1-Principles of Solar Engineering Gozwami Kreith Kreider(2000) pg1
5
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
o Solar Radiation Basics o Domestic Hot Water Heatingo House Heatingo Solar Site Evaluationo Sizing and Costo Questions
4
1972 National Science Foundation Testimony
ldquoSolar energy is an essentially inexhaustible source potentially capable of meeting a significant portion of the nationrsquos future energy needs with a minimum of adverse environmental consequenceshellipthe most promising of unconventional energy sourcesrdquo1
1-Principles of Solar Engineering Gozwami Kreith Kreider(2000) pg1
5
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
1972 National Science Foundation Testimony
ldquoSolar energy is an essentially inexhaustible source potentially capable of meeting a significant portion of the nationrsquos future energy needs with a minimum of adverse environmental consequenceshellipthe most promising of unconventional energy sourcesrdquo1
1-Principles of Solar Engineering Gozwami Kreith Kreider(2000) pg1
5
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Solar radiation comes from the Sun It can be direct diffuse or reflected Radiation is measured by wavelength
Most Solar 01 ndash 30 x 10-6 m (micrometers μm) Thermal Radiation (Heat) Range 01 -100 μm
Solar radiation is used for heating applications by absorbing the solar radiation and transforming it to thermal radiation or energy
6
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
X-Ray Ultra-Violet Visible
Infrared RadioComposite
7
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Insolation Incoming Solar Radiation Measurement of the amount of energy
incident on an area for a given time Insolation includes direct diffuse and
reflected radiation Units
Energy Area x Time BTUft2 hr (English Units) Irsquoll try to stick to
these kWhrm2 day or Wm2 (Metric 1 Watt = 1 Js)
8
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Tilt angle presently 235deg Grotonrsquos Latitude is 426degN On the Summer Solstice the
sun is 709deg from the horizon
On the Winter Solstice the sun is 239deg from the horizon
Tilt gt Distance Sun is closer to Earth in
Winter Sun is more distant in the
Summer
Above Earthrsquos Position at Summer Solstice
9
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Incidence Angle The angle between the sun and the Normal of the surface it strikes
Azimuth Angle The angle between due south and the Normal of the surface
Normal Perpendicular to the surface
10
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
4 Examples to illustrate effect of tilt amp incidence angle
All examples take place at 40degN Latitude (Trenton NJ)
Example 1 Solar noon on the Summer Solstice 45deg (Normal) Roof facing Due South 28deg = incidence angle Percent of max insolation 90 Compare this tohellip Roof 45deg
Facing South 11
90 of max
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
45deg Roof Gained 90 of Maximum Insolation
Example 2 Solar noon on Summer Solstice 0deg (Normal) Wall facing Due South 73deg incidence angle Percent of Max insolation 32
Wall 0deg South Facing
12
32 of max
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Example 3 Solar noon Winter Solstice 0deg (Normal) Wall facing Due South 26deg incidence angle (sun is lower in the
sky) Percent of Max insolation 82
Wall 0deg FacingDue South
13
82 of max
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Wall Facing South Gained 82 of Maximum Insolation
Example 4 Solar noon Winter Solstice 0deg Wall facing South West Same 26deg angle (updown) 45deg East of Due South (leftright) Percent of Max insolation 59
14
Wall 0deg South West Facing (Azimuth = 45deg from S)59 of max
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
The Sun Powerful Clean Inexhaustible Spectrum of wavelengths Thermal vs
Solar Earth Tilt Effects are seasonal Surface Tilt Effects are local Angle between sun and normal to the
surface changes the potential insolation
15
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Terminology Collector Type Collection Methods Other System Components
16
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Terminology Collector Surface that absorbs solar insolation
and transfers it to a working fluid Working fluid Water or antifreeze solution heated
by collector and transfers heat to a storage tank Circulator Pump that moves working fluid through
an active gain system from collector to storage tank
Heat exchanger section of system specifically designed to transfer heat to working fluid or DHW
17
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Collector Type Flat Plate Collector Evacuated Tube Collector
18
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Collector Type Flat Plate Collector Most common type of collector Temperature Range 90deg-160degF Absorber surface is Flat Enclosure Insulated Glazing layerlayers Working fluid moves heat Heat transfer via conduction and forced
convection
19
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Flat Plate Collector Pros
Low up front costs (used collectors are available) Very DIY friendly Good value for Low Temp applications (pool pre-heat tank)
Cons Difficult to insulate well Low collection efficiency Heavy (roof mounting) Glazing issues Incidence angle losses are high
20
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Evacuated Tube Collector New Collector type Temp Range 90deg-250degF Absorber surface inside 2
glass tubes Vacuum between tubes
creates insulating condition
Working fluid in heat pipe boils condenses at end where transfer occurs
Solar radiation always normal to Tube Surface
21
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Evacuated Tube Collector Pros
Very efficient collectors Lightweight High Temp applications (dual-coil DHW tanks) One broken tube doesnrsquot spoil the bunch
Cons Expensive Temperature range can be dangerousdamaging Antifreeze breakdown is quicker Wonrsquot melt snow (too well insulated)
22
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
System Type Active Gain Closed Loop (CL) Active Gain CL Drainback Natural Circulation Thermosiphon
23
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Active GainClosed Loop
24
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Closed Loop System Pros
Can tie into existing DHW system (pre-heat tank) Most common DHW system Minimal controls requirement
Cons Antifreeze or Line heaters required in cold climates Line break could quickly damage system Moving parts = maintenance
25
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Active Gain CL Drainback
26
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Drainback Systems Pros
No need for antifreeze Less maintenance than non-draining CL systems
(not under pressure) Can tie into existing DHW system (pre-heat tank)
Cons More controls required (drainback valve) Less common in industry Moving parts = maintenance
27
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Natural Circulating Thermosiphon System
28
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Thermosiphon Systems Pros
No moving parts Lowest up front costs
Cons Collector must be below storage tank Heat transfer depends on minimizing friction in pipes When collector temp lt storage tank temp flow
reverses Antifreeze required for year-round use in cold climates
29
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Other system components Controller Thermocouples Pumps Storage Tank (Superstore Dual-Coil Outdoor
Shower) Piping (Copper PEX) Expansion tank Reservoir Overheatoverpressure valve Air bleed
30
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Panel Types Flat Plate vs Evacuated Tube
Active Gain Natural Circulation Drainback
Maintenance Antifreeze Tie-in to DHW
31
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Direct Gain Indirect Gain Active systems Passive
systems Storage
systems
32
Bob Gagnonrsquos Evacuated Tube Mega-Array
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
33
bull Open Floor Plan and ceiling fans to reduce heat stratificaitonbull North Side of house burmed into hill to reduce heat lossbull North walls painted browngreenblue to absorb more energy
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
34
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
35
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
36
Two Views Trombe Wall
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
37
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
38
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
39
Fan Coil System Similar to Solar
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
40
Single Coil DHW Tank 1Supplies pre-heated water for on-demand propane heater2Heated water then goes to either DHW or Heat exchanger to heat Radiant Floor Loop
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Best solar designs happen before house is built
Adapting solar is limited without storage
Indirect systems work best for existing homes
Radiant heating systems deliver best value
41
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
How to determine your potential for solar Before going onhelliphellipsome questions to
ponder What are your goals for using solar What is the long term plan for your home What is the energy use in your home How is the expected energy use going to change in
the short-termlong-term What are the aesthetic requirements at your home
42
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Solar Potential Viable solar options depend on having
enough available insolation and enough demand for that heat
Tools to measure available insolation1 Compass Find South minimize shading2 Pyranometer Measures all insolation
DirectDiffuse3 Sun Path diagrams Manual calculation fairly
tricky4 Solar Pathfinder (Available for free)
43
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Solar Pathfinder Software Screen
Allows for multiple inputs
User input latitude tilt and azimuth of each location
Example Upper portion of Leorsquos southeast roof
44
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Pathfinder properly aligned and level
Reflection of surrounding obstructions (trees and buildings) can be seen on dome
Load picture into software for shade trace
Manual trace also an option 45
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
46
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
47
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Final Report Output options
Daily available Insolation
of Ideal Insolation Shading losses Alignment losses KWH generation for PV $ generated by PV array All output given by
month
48
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Insolation is only one piece of the puzzle Other design issues
Heating demand and insolation are naturally out of sync Tilt collector to gain more insolation in winter months
Most shading in morning or afternoon Adjust azimuth and tilt to gain more when insolation comes thru Account for deciduous shading vs coniferous shading Can trees be removedtrimmed
What if the best location for solar is on your lawn Energy audit results will help determine collector size
49
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Non-design considerations CapitalPayback
Investment in Solar must outweigh other investment options
Utility cost reduction is primary measure of payback Reduction in system maintenance amp replacement cost
Rebates Current federal rebates are an UNCAPPED 30 on ALL
work associated with solar energy installation (audits trades tree work parts architects)
Massachusetts rebates are up to 15 cap at $1000
50
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Additional planning into overall house systems should be considered before ldquogoing solarrdquo
Strong evidence supporting GG reduction of over 60 for US homes to reach sustainable carbon emissions level
More than just solar water heating Some of the best options (heat pumps on-demand
heathot water) will affect design of solar application
Energy use data and energy audits are a key step to proper planning and research
httpbliptv Search ldquoGroton Localrdquo Home Energy Audits for more information
51
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Determine Insolation (free) Audit your energy use Set Solar Goals DHW Heat GG
Reduction Determine CapitalPaybackRebates
etc Plan and Execute
52
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
Rules of Thumb Solar Hot Water Avg per capita daily hot water use 18 gallons Energy requirement in NE 12300 BTUday Design collector to cover 100 DHW in June ldquoGoodrdquo site in June will receive daily insolation
~ 1700 BTUft 2
Flat plate efficiency 35-70 15 ft 2person Evac Tube efficiency 45-85 9 ft 2person Cost ~$3-5K Flat Plate $8-10K Evac Tube
53
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
The Challenge Coldest day this year Avg T = 26degF 11609On such a day Avg heat load per house 1 million BTUday Avg insolation in January 536 BTUsq ftday Area of 100 efficient collector to cover this
demand 1865 square feet
54
