Autonomous Solar StrategiesSept. 13, 2004http://www.uvm.edu/~gflomenh/CDAE170/

Gary Flomenhoft, BSME, MPP, CEEResearch Associate, Gund Institute, SNR

Why Solar?

World Oil Extraction

Peak Gas and Oil

The Epoch of Fossil Fuel Exploitation(after Hubbert, 1969)

0-5 -4 -3 -2 -1 +1 +2 +3 +4 +5

Iron inMiddleEast

StonehengeBuilt

Parthenoncompleted

Pyramidsconstructed

Mayanculture

Inquisition

BlackDeath

Magellan'sCircumnavigation

Steam Engine

100

200

300

Tri

llio

n k

wh

per

yea

r

Prices = Economic Scarcity

What is the scarce resource?

Scarce resource but no price150 years for feedback

Forms of Solar

GREECE

CHINA

HELIOCAMINUS

DUTCH

WINDOW INSULATION-DUTCH

HORTICULTURE

CONSERVATORY HEAT

ROOF GARDENS

SOLAR HOT DOGS

How much solar?

Vermont Fuel choices

VT Electric Energy Supply Mix2001 Vermont Own Load Electric Energy

Supply

Nuclear36.3%

Renewable4.9%Hydro

6.9%Gas

1.0%Coal0.0%Oil

1.6%

Hydro Quebec34.9%

System14.4%

John’s HouseRough Lumber from Local Mill

Spruce Siding from Local Mill

Roof Slate Recycled from Old Barn

House is Super Insulated (R 30 walls dense-pack cellulose)

Casement Windows are R 6

Heat w/ Wood, 1 cord/winter

Back-up radiant heat

1400 square feet + basement

Greenhouse is mostly recycled

Double Pane Glass in Greenhouse

Greenhouse Wood is Salvaged old-growth Cypress

NO PLYWOOD!

Passive Solar Building Strategies

1. Choose a good site.2. Orient east-west and 10deg to TRUE south3. Locate most windows on south side 7-12% of ft2.

4. Minimize windows on N,W,E sides5. Provide overhangs or shading to regulate solar gain6. Thermal storage mass7. Insulate walls, ceilings, floors, foundations, & windows8. Protect insulation from moisture9. Seal house against air infiltration; provide air

exchange10. Provide direct solar heat to each room11. Create sun free spaces12. Provide properly sized eco-friendly back-up13. Protect from wind by landscape or earth berm14. Synchronize design with living patterns

1. Choose a good site

MO. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

%SUN 34% 43% 48% 47% 53% 59% 62% 59% 51% 43% 25% 24%

HDD 1513 1333 1187 714 353 90 28 65 207 539 891 1349

TEMP WINTER=29.4F HDD=<65F = <70F INTERIOR TOT 8269

BURLINGTON, VT DATA

1. Choose a good site-bearing angle

1. Choose a good site-Altitude angle

1. Choose a good site

2. Orient EAST-WEST AXIS to TRUE south

STOP

2. Orient within 10deg to TRUE south

2800 km2800 km

2. Orient within 10deg to TRUE south

2. Orient within 10deg to TRUE south

Declination (variation)

2. Orient within 10deg to TRUE south

PASSIVE SOLAR DESIGN-5 Design Elements

PASSIVE DESIGN

PASSIVE DESIGN

PASSIVE DESIGN

PASSIVE DESIGN-Direct Gain

PASSIVE DESIGN

Indirect Gain: Trombe wall (unvented)

Indirect Gain: Trombe Wall: vented

(Thermal storage or Trombe wall)

Vented Trombe wall

Indirect gain: Sunspace

Ted Montgomery’s Green Home

Garden Room

Looking South is a Sunroom Topped with PVs

Review of Indirect Gain Principles-Chiras

1. Orient south +-10 degrees

2. High performance glass

3. Thermally isolate glass

4. High quality caulk

5. Use Selective surface or high temp paint

6. Use dense material

7. Minimal interior finish

8. Insulate glass at night

Direct + Indirect glazing = MAX 20% of floor area

Selective Surfaces

3. Locate most windows on south side

South glass: 7-12% of floor footage SQUARE FOOTAGE = HEATED FLOOR AREA

EXAMPLE: 12% OF 3000 SQ FT = 360 SQ FT

4. Minimize windows on N,W,E sides North glass: <=4%East glass: <=4%West glass: <=2%Use low-e multiple panes

Windows-Yestermorrow

• Windows Facing South

• Ventilation throughout building

• Triple pane glass

PASSIVE DESIGN

What kind of windows?

What kind of windows?

What kind of windows?

What kind of windows?

What kind of windows?

What kind of windows?

What Kind of Windows?

Window insulation

5. Provide overhangs or shading to regulate solar gain

5. Provide overhangs or shading to regulate solar gain

L = Length of Projection

H = Height of window opening

L = H / F 44º latitude: F=2.0-2.7

5. Provide overhangs or shading to regulate solar gain

5. Provide overhangs or shading to regulate solar gain

6. Thermal mass-maximize surface area

Sun-tempered = 7% of floor footage. Incidental mass takes care of it (sheetrock, framing, furniture)

>7% glazing needs extra mass.

MASS 4-6” thick: *Mass proportional to glazing*

DIRECT FLOOR MASS: Each square foot of glazing over 7% x 5.5 orINDIRECT FLOOR MASS: glazing >7%sq.ft. x 40orINDIRECT WALL MASS: glazing >7% x 8.3

6. Thermal mass-Values

Adobe 20

Brick 24

Concrete 35

Earth 20

sand 22

Steel 59

Stone 35

water 63

wood 10.6

Insulated Thermal Mass Floor In Sunroom

6. Thermal mass

Radiant Heat Floor: Stained Cement

6. Thermal mass

6. Thermal mass

Solar Storage in Cans Full of High-Performance Salt(phase change)

6. Thermal mass

7. Insulate Walls, ceiling, floors, foundations, & windows

Recommendations: (Olson and Schwartz)

Climate Wall ceiling

Temperate R-30 R-60

Cold R-40 R-80

Hot R-40 R-80

Kachadorian(Vermont)

R-32 R-40

Fiberglass/cellulose = R3/inch

R-80 = 27”!

7. Insulation

7. Insulate Walls, ceiling, floors, foundations, & windows

7. Insulate Walls, ceiling, floors, foundations, & windows

7. Insulation-cold attic

7. Insulation-cold attic

7. Insulation-cathedal ceiling or warm attic-roof spans

7. Insulation

7. Insulation-summary

Saskatchewan superinsulated house quote.

8. Protect insulation from moisture:

Use vapor barrier on warm side

9. Seal House against air infiltration; provide air exchange

9. Seal house against infiltration; provide air exchange

10. Provide direct solar heat to each room-clerestories

10. Provide direct solar heat to each room-clerestories

Cordwood construction

10. Provide direct solar heat to each room-Skylight

10. Provide direct solar heat (&light) to each room

10. Provide direct solar heat (&light) to each room

“Solar Tubes” Day Lighting

11. Create sun-free spaces

“Solar Tubes” From Inside

11. Create sun-free spaces

Central Wood Pellet Boiler

12. Provide properly sized eco-friendly back-up

Wood Pellets

12. Provide properly sized eco-friendly back-up

Berming for InsulationAndWind protection

Prefinished metal roof

13. Protect from wind by landscaping or earth berm

14. Synchronize with living patterns?

SOLAR HOT WATER SYSTEMS

Solar Hot water: Collectors-Flat Plate

Solar Hot water: Collectors-Flat Plate

Solar Hot Water Collectors-Evacuated tube

Solar Hot Water Collectors-Evacuated tube

100% heat and hot water/no fuel-ground source heat pump

Photovoltaic Systems

(Electricity)

Photovoltaic Systems- Rigid panels on roof

PV Systems-BIPS-standing seam metal systems

PV Systems- BIPS-Field Applied Roofing Laminate (PVL)

PV Systems-BIPS “sunslate” solar tiles

PV Systems-Sunslate tile (crystalline)

PV Systems-BIPS: Uni-Solar tiles (amorphous)

PV Systems-BIPS Uni-solar tiles

100% power Vermont -Combine PV & wind w/grid intertie=less batteries

100% power-Grid tie & independent inverter