Solar-Thermal Feasibility Study Farm #1 Dairy Operation #1.pdf · Solar-Thermal Feasibility Study Farm #1 Dairy Operation Mirko Slivar Stantec Consulting Ltd. Suite 300 – 175 2nd

Solar-Thermal Feasibility Study Farm #1 Dairy Operation

Mirko Slivar ● Stantec Consulting Ltd.

Suite 300 – 175 2nd Avenue, Kamloops, B.C.

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Prepared for:

Prepared by:

Stantec Consulting Ltd. Suite 300 – 175 2nd Avenue Kamloops, B.C. V2C 5W1

Contact: Mirko Slivar, P.Eng., CEM Tel: 250-852-5923

Project #112120757

July 17, 2012

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TABLE OF CONTENTS

LIST OF FIGURES AND TABLES .............................................................................................. 4

1 EXECUTIVE SUMMARY ..................................................................................................... 5

2 SITE INFORMATION ......................................................................................................... 6

2.1 FARM OPERATION .......................................................................................................... 6 2.2 LOCATION .................................................................................................................... 6 2.3 EQUIPMENT................................................................................................................... 6 2.4 UTILITY INFORMATION ................................................................................................... 6

3 THERMAL LOAD CALCULATIONS ...................................................................................... 7

3.1 HOT WATER .................................................................................................................. 7 3.2 CHILLED WATER ............................................................................................................ 7

4 SOLAR-THERMAL SYSTEM SELECTION ............................................................................. 8

4.1 SOLAR HOT WATER ........................................................................................................ 8

5 SOLAR-THERMAL SYSTEM SIZING ................................................................................. 10

5.1 SOLAR HOT WATER ....................................................................................................... 10 5.1.1 MANUAL METHOD ............................................................................................................ 10 5.1.2 RETSCREEN METHOD ........................................................................................................ 12 5.1.3 NOTE ON MANUAL VERSUS RETSCREEN RESULTS .......................................................................... 13

6 FINANCIAL ANALYSIS ................................................................................................... 14

6.1 SCENARIO #1: MINIMUM PRICE OF FUEL REQUIREMENT .................................................... 14 6.2 SCENARIO #2: CAPITAL FUNDING REQUIREMENT ............................................................. 15 6.3 SCENARIO #3: RENEWABLE HEAT INCENTIVE REQUIREMENT ............................................. 15

APPENDIX A – DETAILED CALCULATION OF HOT WATER USAGE ......................................... 17

APPENDIX B – MANUAL CALCULATIONS OF SOLAR POTENTIAL .......................................... 19

APPENDIX C – RETSCREEN RESULTS FOR SOLAR HOT WATER ............................................ 21

APPENDIX D – FINANCIAL ANALYSIS DATA ........................................................................ 22

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LIST OF FIGURES AND TABLES

Figure 1. Schematic of Closed-Loop Solar Hot Water System for Farm #1 ...................................... 9

Figure 2. Monthly Radiation - Incident and Usable for Farm #1 .................................................... 10

Figure 3. Hot Water Demand Versus Solar Hot Water Output for Farm #1 ..................................... 11

Table 1. RETScreen Solar Hot Water Inputs for Farm #1 ............................................................. 12

Table 2. Comparison Between Manual and RETScreen Results for Farm #1 .................................... 13

Table 3. Scenario #1: Minimum Price of Fuel Requirement for Farm #1 ........................................ 15

Table 4. Scenario #2: Capital Funding Requirement for Farm #1 ................................................. 15

Table 5. Scenario #3: Renewable Heat Incentive Requirement for Farm #1 ................................... 16

Table 6. Summary of Monthly Radiation - Incident and Usable for Farm #1 ................................... 19

Table 7. Detailed Monthly Radiation Data for Farm #1 ................................................................ 20

Table 8. RETScreen Solar Hot Water Model for Farm #1 ............................................................. 21

Table 9. Financial Analysis Data for Farm #1............................................................................. 22

FARM # 1 SOLAR-THERMAL FEASIBILITY STUDY

Stantec Consulting Ltd. 5

1 EXECUTIVE SUMMARY

B.C.'s agricultural sector consumes significant quantities of energy. Renewable energy from the sun present agricultural operators with an opportunity to decrease their utility costs, become more energy independent and reduce the environmental impacts of their operations.

This study looked at the potential of using solar-thermal systems (namely hot water, chilled water and heated air) for heating and cooling on a dairy farm, located in the Fraser Valley.

A dairy farm uses hot water for cleaning and equipment sterilization, and uses refrigeration for cooling the milk. Dairy barns are open structures that are un-insulated and rely on natural ventilation. In summer, fans are used to move the air for a cooling effect.

Water heating can account for up to 15 per cent of a dairy farm's total energy use; refrigeration can account for up to 21 per cent of total energy use; and ventilation can account for up to 12 per cent of total energy use (Ontario fact sheet: Using Less Energy on Dairy Farms).

There is a potential for using both solar-thermal hot water and chilled water on this dairy farm. Since the dairy only uses natural ventilation and fans, and the ventilation air is neither heated nor cooled, there is no application for solar-thermal heated air.

This dairy uses about 3,300 litres of water at 82 C per day, which is heated by an 80 per cent efficient natural gas hot water tank. Installing a 60-collector solar hot water system at an estimated cost of $250,000 will reduce the dairy's annual energy use for hot water from about 488 GJ to 100 GJ for an annual saving of about $3,860.

Due to the low cost of natural gas this study concludes that to make the proposed solar hot water system financially viable, one of the following conditions must be met:

1) The price of natural gas would need to increase from $9.94/GJ to $25.00/GJ based on a 10 per cent return on investment; or

2) A one-time capital cost rebate of $114,840 (equivalent to $825 per square metre of solar collector or 45 per cent of total installed cost) is needed based on a 5 per cent return on investment; or

3) A renewable heat incentive of $0.054/kWh of heat energy produced over a 25-year period is needed based on a 10 per cent return on investment.

This dairy produces about 1,700 litres of milk a day, which must be cooled down to 4 C from 37 C within one hour of milking. This is done using two 10-ton chillers. The milk is then stored at 2.2 C for up to two days in a 1,600 US-gallon refrigerated storage tank before the milk is taken away for processing. Solar chilled water systems are limited to delivering down to a temperature of 7 C; therefore this type of system is not suitable for this operation.

Budget estimates provided in this study are generalized costs. The above findings are based on current figures and current industry practices and as such can change with time, with location and with physical on-site findings. Hence, these findings may prove to be more or less viable upon a detailed engineering design and competitive pricing.

This paper is part of the Benchmarking of Solar-Thermal Technologies in B.C.'s Agricultural and Agri-Food Operations (a.k.a. main feasibility study) and should be referenced as such. Other agricultural and agri-food operators can use this paper to determine the suitability of using solar-thermal systems at their own operations.



2 SITE INFORMATION

On this dairy farm, there are cows to be milked 365 days of the year, twice a day (every 12 hours around 5 a.m. and 5 p.m.). The milk is cooled down to 4 C from 37 C within one hour of milking to preserve freshness. This is done using two 10-ton chillers. The milk is then stored at 2.2 C for up to two days in a 1,600 US-gallon refrigerated storage tank before the milk is taken away for processing.

Hot water is used for cleaning and sterilization. Milking equipment and pipes are washed twice a day while the storage tank is washed every second day. Typical cleaning consists of four wash cycles: warm water pre-wash rinse (35 to 43 C); hot water wash (70 C); warm water acid rinse (35 to 43 C); and 30 minutes before milking a sanitize cycle with cold or warm water depending on the sanitizer used (B.C. Dairy Talk: Mastering Milk Quality Basics of Dairy Sanitation). Cleaning and sterilization takes a total of about 4 hours a day. The barns are open structures that are un-insulated and rely on natural ventilation. In summer, fans are used to move the air for a cooling effect.

2.1 FARM OPERATION

The dairy has about 100 cows and produces 620,000 litres of milk annually.

2.2 LOCATION

Rosedale, B.C.

Latitude 49.5 degrees and longitude 121.5 degrees.

This farm, located in the Fraser Valley, has good southern exposure to capture the sun with no shading issues from buildings, trees or mountains. There is ample space to mount solar collectors on the roof and/or the ground.

2.3 EQUIPMENT

One 400,000 Btu/h (80 per cent efficient) 81 US-gallon natural gas hot water tank set at 82 C.

Two 10-ton chillers to cool the milk.

One 1,600 US-gallon refrigerated storage tank where milk is kept at 2.2 C.

2.4 UTILITY INFORMATION

For the past year ending March 9, 2012, the dairy used about 91,000 kWh of electricity at a total cost of about $8,200 (estimated from March 2012 utility bill). This electrical consumption was used to operate the milking equipment, milk cooling system, lights, ventilation and other electrical equipment. In addition, the farm used about 732 GJ of natural gas at a total cost of about $7,276 (estimated from March 2012 utility bill). This natural gas consumption was used for hot water, domestic hot water, space heat in office and farmer's house, and for heating season outdoor swimming pool. The operation does not use propane.



3 THERMAL LOAD CALCULATIONS

There is a potential for using both solar-thermal hot water and chilled water on this dairy farm. Since the dairy only uses natural ventilation and fans, and the ventilation air is neither heated nor cooled, there is no application for solar-thermal heated air.

3.1 HOT WATER

In order to design a solar hot water system the farmer will need to know his daily hot water usage in litres per day. In this example, the dairy owner does not know his hot water usage, so it was calculated using the natural gas utility bill and the equation:

Q = 500 x gpm x ∆T

Where:

Q is the heat energy (Btu/h).

gpm is the flow rate (US-gallon/minute).

∆T is the temperature rise (F).

We are given:

Annual natural gas consumption 732 GJ (used for hot water, domestic hot water, space heat in office and farmer's house, and for heating season outdoor swimming pool).

Dairy operation uses an 80 per cent efficient natural gas hot water tank.

Hot water usage 4 hours per day.

Hot water temperature 82 C.

Incoming supply water temperature 4 C.

Calculated:

Dairy uses about 3,300 litres of water at 82 C per day. For a step-by-step calculation see Appendix A.

3.2 CHILLED WATER

This dairy produces about 1,700 litres of milk a day, which must be cooled down to 4 C from 37 C within one hour of milking. This is done using two 10-ton chillers. The milk is then stored at 2.2 C for up to two days in a 1,600 US-gallon refrigerated storage tank before the milk is taken away for processing. Solar chilled water systems are limited to delivering down to a temperature of 7 C; therefore this type of system is not suitable for this operation.



4 SOLAR-THERMAL SYSTEM SELECTION

Of the potential solar-thermal systems explored in this study (namely hot water, chilled water and heated air), solar hot water is most suitable for this operation.

4.1 SOLAR HOT WATER

The dairy farm in this study has a good application for solar hot water because it requires hot water daily; the site has good southern exposure to capture the sun with no shading issues from buildings, trees or mountains; and the site has plenty of space on the roof to mount solar collectors. Dairy operating parameters:

Latitude 49.5 degrees and longitude 121.5 degrees.

Hot water usage of 3,300 litres per day.



Year-round use (system requires freeze protection).

Peak demand around 5 a.m. and 5 p.m. (system requires storage tank).

Given the above requirements a closed-loop solar hot water system was chosen for this case study. Figure 1 illustrates the operation of a closed-loop system.

When the sun is out the collector heats up and the controller turns on the pump to transfer heat from the collector to the storage tank via the heat transfer fluid. In B.C., all solar hot water systems that operate during the winter require some sort of antifreeze protection. This can be achieved by installing a closed-loop system with a water-propylene glycol solution as the heat transfer fluid.

The expansion tank minimizes pressure changes in the system due to volume change of the heat transfer fluid as the system heats up.

Solar collector performance varies amongst manufacturers and the type of collector. For solar hot water systems collectors are divided into flat plate and evacuated tube. Both types of collectors are suitable for this application. However, there are two advantages to choosing a flat plate collector over an evacuated tube collector:

1) Flat plate collectors cost less than evacuated tube collectors ($900 per collector and $3,500 per collector respectively); and

2) In cold weather a flat plate collector has the ability to melt snow and continue to operate, whereas an evacuated tube collector will not melt snow and will not operate when covered.

Because a solar hot water system can only produce heat when the sun shines and the dairy's peak demand for hot water occurs around 5 a.m. and 5 p.m., a well-insulated storage tank will be necessary to store the heat until it is needed. Refer to the main feasibility study for a detailed discussion on how solar hot water systems work.



Figure 1. Schematic of Closed-Loop Solar Hot Water System for Farm #1



5 SOLAR-THERMAL SYSTEM SIZING

5.1 SOLAR HOT WATER

Sizing of solar hot water system for this case study was done using two methods: manual calculations and then again using RETScreen (a free software program used to review renewable energy projects). It is not anticipated that an agricultural operator will perform manual calculations. This method is included for benchmarking and informational purposes. It is expected agricultural operators will either retain a suitable solar consultant or use a software program such as RETScreen.

5.1.1 MANUAL METHOD

The general procedure for carrying out the manual calculations is:

1) Determine monthly hot water demand (refer to Appendix A).

2) Determine monthly solar radiation available (refer to Appendix B).

3) Calculate amount of usable solar radiation based on operating parameters (refer to Appendix B).

4) Determine the number of solar collectors required.

For this case study, the energy input from the sun to a square metre of south-facing collector is about 1,447 kWh annually; and the energy output of a square metre of south-facing collector is about 618 kWh annually. Figure 2 shows the energy input (green line) and usable energy (red line) for this site. Peak production occurs in July with 80 kWh per square metre of collector, and production drops to a low of 17 kWh per square metre of collector in December.

Figure 2. Monthly Radiation - Incident and Usable for Farm #1



Generally, solar hot water systems are sized to supply 60 to 70 per cent of the annual hot water demand so that the likelihood of over sizing the system during summer peak solar intensities is minimized. Based on dairy's annual energy demand for hot water of 488 GJ about 60 collectors could be installed as calculated:

Convert GJ to kWh = 488 GJ divide by 0.0036 kWh/GJ = 136,000 kWh

Annual hot water demand = natural gas used x efficiency of hot water tank = 136,000 kWh x 0.80 = 108,800 kWh

Assume a load saving of 70 per cent due to solar = 108,800 kWh x 0.70 = 76,160 kWh

Annual usable solar from collector from Table 6 = 618 kWh/m2

Area of collector required = 76,160 kWh divide by 618 kWh/m2 = 123 m2

Number of collectors = 123 m2 divided by standard collector aperture 2.32 m2 = 53

These 60 collectors would produce about 310 GJ of annual solar hot water energy, which is about 80 per cent of the annual hot water energy required. Figure 3 shows the hot water demand (green line) versus the solar hot water output for a 60-collector system (red line). As shown, it is possible to use the sun to provide most of the hot water demand from April to September, and to obtain useful preheating of water during the other months of the year.

Figure 3. Hot Water Demand Versus Solar Hot Water Output for Farm #1



The proposed 60-collector solar hot water system will reduce the dairy's annual natural gas energy use for hot water from 488 GJ to 100 GJ for an annual saving of about $3,860 as calculated:

Annual solar hot water energy = 60 collectors x standard collector aperture 2.32 m2 x 618 kWh/m2 x 0.0036 GJ/kWh = 310 GJ

Natural gas offset = annual solar hot water energy divided by efficiency of hot water tank = 310 GJ divided by 0.80 = 388 GJ

Annual natural gas savings = 388 GJ x $9.94/GJ = $3,860

5.1.2 RETSCREEN METHOD

RETScreen is a useful tool when it comes to making a decision about whether or not it is financially viable to use renewable energy technologies like solar hot water. Some of the user inputs are technical in nature so we have included user inputs and helpful comments, shown in Table 1, to assist agricultural producers who want to perform their own feasibility analysis using this program. A more detailed explanation of user inputs can be found in the main feasibility study. See Appendix C for RETScreen solar hot water energy model results for this case study.

Table 1. RETScreen Solar Hot Water Inputs for Farm #1

Variable Input Comment

Daily hot water use 3,360 litres/day Calculated from utility bill

Hot water temperature 82 C Temperature set on hot water tank

# of days per week solar water heater use 7 Dairy operates everyday of the week

Supply temperature method user defined 4 C Given incoming supply water temperature

Solar tracking mode fixed Typical installation in B.C.

Slope of solar collector 40 Rule of thumb for B.C.

Azimuth 0 Collectors pointed directly south

Type of collector glazed Efficient for this application

Manufacturer of collector Viessmann Leading manufacturer of solar collectors

Model of collector Vitosol 100-F SV1 Efficient collector

# of collectors 60 Estimated

Miscellaneous solar heater losses 2% Typical value

Storage yes

Have to either use the heat as it is being generated or store it for when needed later in the day (at 5 a.m. and 5 p.m. peak demand)

Storage capacity per collector area 70 litres/m2

60 to 80 litres/m2 for intermittent usage generally allows flexibility for finding off the shelf tanks, is able to handle most overheating situations and has been verified by industry associations

Heat exchanger yes Year-round system requires antifreeze protection (part of closed-loop system)

Heat exchanger efficiency 98% Typical value

Miscellaneous system losses 2% Typical value

Pump power per collector 15 W/m2 Typical value

Electricity rate 0.09 $/kWhUsed by the program to calculate the cost of electricity used to operate the solar system

Fuel type natural gas Fuel used to heat the water in your facility

Seasonal efficiency 80% Typical value

Fuel rate $9.94/GJ Cost of fuel used to heat the water in your facility

RETScreen Inputs



5.1.3 NOTE ON MANUAL VERSUS RETSCREEN RESULTS

As a comparison, Table 2 is a summary of the calculation results from both the manual and RETScreen method. As shown, the results are very similar.

Table 2. Comparison Between Manual and RETScreen Results for Farm #1

Manual vs RETScreen Results

Variable Manual Calculations RETScreen Calculations

Number of collectors 60 60

% of annual hot water energy offset by solar 80 60

Estimated annual $ saved $3,860 $3,000

Estimated annual GJ saved 388 302



6 FINANCIAL ANALYSIS

To supply and install a solar hot water system can budget on spending $1,800 per square metre of flat plate collector. This budget cost is an established industry standard from numerous installations and includes materials, labour and permitting for a fully operational system as follows:

Flat plate collectors 35 per cent

Storage tanks 15 per cent

Controls 10 per cent

Miscellaneous (pumps, insulation, mixing valve, mark up and profit) 40 per cent

The above price percentages are for a typical installation and may change depending on each installation’s characteristics.

The financial analysis that follows is based on the installation of a 60-collector solar hot water system at a total cost of $250,000 (60 collectors x standard collector aperture 2.32 square metre x budget $1,800 per square metre of flat plate collector).

To determine the incentive required to make the proposed solar hot water system financially viable three scenarios were investigated:

1) What does the minimum price of fuel have to be?

2) What one-time upfront capital payment does there need to be?

3) What renewable heat incentive does there need to be?

The return on investment for scenarios one and three above was set at 10 per cent and for the capital payment scenario a 5 per cent return on investment was deemed reasonable in relation to operator's reduced capital cost and the associated risks. For this study a Chabot profitability index of 0.3 was used and is defined as the net present value of the sum of the discounted energy bills over n years of operation divided by the initial investment cost (refer to the main feasibility study for a more detailed discussion on financial analysis and the use of the Chabot profitability index.)

For reference see Appendix D for the calculated net present values over 25 years (analysis period) of the discounted energy bills, cost of maintenance and cost of electricity needed to operate the solar hot water system.

6.1 SCENARIO #1: MINIMUM PRICE OF FUEL REQUIREMENT

This scenario looked at what the minimum energy price, by fuel type, would need to be to make the proposed solar hot water system financially viable today. Table 3 is a summary of the findings.

For the dairy farm in this study the cost of natural gas would need to increase by 152 per cent from $9.94/GJ to $25.00/GJ.

However, if the dairy farm didn't have access to natural gas and had been using electricity to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity of $0.09/kWh. Furthermore, if the farmer had been using propane to heat water, then the cost of propane would need to increase by 11 per cent from $0.55/L to $0.61/L.



Table 3. Scenario #1: Minimum Price of Fuel Requirement for Farm #1

Variable Current Cost of Energy

Required Cost of Energy

Utility Rate 9.94$ 25.00$



Fuel Type

Natural Gas ($/GJ)

Electric ($/kWh)

Scenario 1 Summary

Propane ($/L)

6.2 SCENARIO #2: CAPITAL FUNDING REQUIREMENT

This scenario looked at the one-time capital payment, by fuel type, that would be required to make the proposed solar hot water system financially viable given today's energy prices. Table 4 is a summary of the findings.

The dairy farm in this study would need a one-time capital incentive of $114,840 for a 60-collector system. This capital incentive amounts to 45 per cent of the total cost of installing a solar hot water system.

However, if the dairy farm didn't have access to natural gas and had been using either electricity or propane to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity or propane ($0.09/kWh and $0.55/L respectively).

Table 4. Scenario #2: Capital Funding Requirement for Farm #1

Fuel Type Variable Current

Capital Cost ($/m 2)

Required Capital Grant

($/m 2)

Natural Gas Capital Cost 1,800$ 825$

Electric Capital Cost 1,800$ not required

Propane Capital Cost 1,800$ not required

Scenario 2 Summary

6.3 SCENARIO #3: RENEWABLE HEAT INCENTIVE REQUIREMENT

This scenario looked at the renewable heat incentive, by fuel type, that would be required over a 25-year period to make the proposed solar hot water system financially viable given today's energy prices. In other words, an incentive based on the amount of energy saved through on-site heat production. Table 5 is a summary of the findings.

The dairy farm in this study would need a renewable heat incentive of $0.054/kWh of heat energy produced over a 25-year period. This amounts to the government paying the farmer $4,650 per year on heat energy produced.



However, if the dairy farm didn't have access to natural gas and had been using electricity to heat water, the financial analysis tells us it would be viable today to install a solar hot water system based on the local price of electricity of $0.09/kWh. Furthermore, if the farmer had been using propane to heat water, then would need a renewable heat incentive of $0.009/kWh of heat energy produced over a 25-year period.

Table 5. Scenario #3: Renewable Heat Incentive Requirement for Farm #1

Current Cost of Energy

Current Cost of Energy

($/kWh)

Required Incentive on Fuel Saved

Equivalent Incentive on Fuel Saved

($/kWh)

9.940$ 0.036 15.06$ 0.054

0.090$ 0.090 not required not required

0.550$ 0.080 0.060$ 0.009

Renewable heat incentiveElectric ($/kWh)

Propane ($/L) Renewable heat incentive

Renewable heat incentive

Fuel Type

Natural Gas ($/GJ)

Variable

Scenario 3 Summary



APPENDIX A – DETAILED CALCULATION OF HOT WATER USAGE

To calculate hot water usage using natural gas utility bill and the equation:

Q = 500 x gpm x ∆T

Where:

Q is the heat energy (Btu/h).

gpm is the flow rate (US-gallon/minute).

∆T is the temperature rise (F).

We know for Farm #1:

Annual natural gas consumption 732 GJ (used for hot water, domestic hot water, space heat in office and farmer's house, and for heating season outdoor swimming pool).

Dairy operation uses an 80 per cent efficient natural gas hot water tank.

Hot water usage 4 hours per day (1,460 hours per year).



Calculate Q heat energy

1) Calculate the natural gas used in house for space heating and hot water. We know the average house in B.C. uses 0.61 GJ of energy per square metre annually, of which 55 per cent is used for space heating and 22 per cent is used for heating water (Source: Natural Resources Canada 2009 stats). Size of house estimated to be 250 m2. Hence, amount of natural gas used annually in house for space heating and hot water = 0.61 GJ/m2 x 250 m2 x 0.77 = 117 GJ.

2) Calculate the natural gas used in office for space heating. For the office we assume space heating uses 1.2 GJ of energy per square metre annually. Size of office estimated to be 80 m2. Hence, amount of natural gas used annually in office for space heating = 1.2 GJ/m2 x 80 m2 = 96 GJ.

3) The owner stated the pool heater is turned on for a short period early in the summer to get the water warm. The annual natural gas usage could be clearly read off the utility bill = 31 GJ.

4) Therefore, annual natural gas used to heat water for dairy operation = 732 – 117 – 96 – 31 = 488 GJ/year.

5) Annual energy to heat water for dairy operation = natural gas used x efficiency of hot water tank = 488 GJ/year x 0.80 = 390 GJ/year.

6) Convert GJ to Btu = 390 GJ/year x 947,817 Btu/GJ = 369,648,630 Btu/year.

7) Q = 369,648,630 Btu/year divided by 1,460 hours/year of water usage = 253,184 Btu/h.

Calculate ∆T temperature rise

1) ∆T = hot water temperature minus incoming supply water temperature = 82 C – 4 C = 78 C

2) Convert C to F = 78 C x 1.8 F/C = 140 F

Calculate gpm flow rate



1) From equation Q = 500 x gpm x ∆T

Where:

Q = 253,184 Btu/h

∆T = 140 F

Therefore:

gpm = 253,184 divided by (500 x 140) = 3.6 gpm

Calculate daily hot water usage

1) Daily hot water usage = 3.6 gpm x 240 minutes = 864 US-gallons

2) Convert US-gallons to litres = 864 US-gallons x 3.78 litres/US-gallon = 3,266 litres

Dairy uses about 3,300 litres of 82 C water a day.



APPENDIX B – MANUAL CALCULATIONS OF SOLAR POTENTIAL

Table 6. Summary of Monthly Radiation - Incident and Usable for Farm #1

kWh/m2-day kWh/m2-month kWh/m2-month %

A B C D E

Jan 1.93 60 26 44

Feb 3.07 86 41 48

Mar 4.10 127 57 45

Apr 5.03 151 68 45

May 5.33 165 74 45

Jun 5.31 159 70 44

Jul 5.74 178 80 45

Aug 5.47 170 76 45

Sep 4.61 138 55 40

Oct 3.10 96 34 35

Nov 2.11 63 19 30

Dec 1.71 53 17 32

1447 618 43

5.2 2.2 43

Farm #1

MonthIncident Solar Usable Solar

kWh/m2-yr:

GJ/m2-yr:

Column A: Month Column B: The daily averaged solar radiation incident on an equator-pointed 34° tilted surface (relative to the horizontal) (NASA data) Column C: The monthly averaged solar radiation incident on an equator-pointed 34° tilted surface (relative to the horizontal) (column B x # of days in month) Column D: The monthly averaged solar radiation captured and usable on an equator-pointed 34° tilted surface (relative to the horizontal) Column E: The percentage of incident solar radiation captured and usable

For this site, the energy input from the sun to a square metre of south-facing collector is about 1,447 kWh annually; and the energy output of a square metre of south-facing collector is about 618 kWh annually. The average annual operating efficiency of the collector (Viessmann flat plate model Vitosol 100-F SV1) is about 43 per cent. Results would be similar for other brands of flat plate collectors.



Table 7. Detailed Monthly Radiation Data for Farm #1

The monthly solar potential is site specific and is calculated using NASA solar radiation incident data, NRCan weather data and operating performance for Viessmann flat plate collector (model Vitosol 100-F SV1). Results would be similar for other brands of flat plate collectors.

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Jul

0.69

44.

452

22.1

5.74

6643

.956

3.2

0.10

0.45

2.58

80

Aug

0.69

44.

452

22.5

5.47

6643

.555

8.1

0.10

0.45

2.46

76

Sep

0.69

44.

452

18.9

4.61

6344

.156

5.8

0.12

0.40

1.84

55

Oct

0.69

44.

452

13.6

3.10

4935

.445

4.2

0.15

0.35

1.09

34

Nov

0.69

44.

452

7.1

2.11

3830

.939

6.4

0.19

0.30

0.63

19

Dec

0.69

44.

452

3.8

1.71

2723

.229

7.7

0.17

0.32

0.55

17

Col

umn

B:

Opt

ical

eff

icie

ncy

is t

he f

ract

ion

of s

olar

rad

iatio

n w

hich

pas

ses

thro

ugh

the

outs

ide

colle

ctor

gla

ss a

nd r

each

es t

he a

bsor

ber

and

is a

ctua

lly a

bsor

bed

for

a V

iess

man

n fla

t pl

ate

colle

ctor

Col

umn

C:

Col

lect

or h

eat

loss

fac

tor

is a

pro

pert

y of

the

col

lect

or c

hose

n

Col

umd

D:

Ave

rage

mon

thly

day

time

tem

pera

ture

(N

RC

an d

ata)

Col

umn

E: T

he d

aily

ave

rage

d so

lar

radi

atio

n in

cide

nt o

n an

equ

ator

-poi

nted

34°

tilt

ed s

urfa

ce (

rela

tive

to t

he h

oriz

onta

l) (

NA

SA

dat

a)

Col

umn

F: A

ppro

xim

ate

aver

age

fluid

tem

pera

ture

ent

erin

g th

e co

llect

or (

calc

ulat

ed v

alue

)

Col

umn

G:

Tem

pera

ture

diff

eren

ce b

etw

een

fluid

ent

erin

g co

llect

or a

nd a

vera

ge d

aytim

e te

mpe

ratu

re (

colu

mn

F -

colu

mn

D)

Col

umn

H:

The

criti

cal i

nten

sity

is in

dica

tive

of t

he le

ngth

of

time

in e

ach

day

duri

ng w

hich

the

col

lect

or p

rodu

ces

ener

gy (

calc

ulat

ed v

alue

)

Col

umn

I: T

his

fact

or is

an

exte

nsio

n of

col

umn

H a

nd in

volv

es t

he c

ritic

al in

tens

ity a

nd t

he p

erio

d of

col

lect

or o

pera

tion

(cal

cula

ted

valu

e)

Col

umn

J:

The

perc

enta

ge o

f in

cide

nt s

olar

rad

iatio

n ca

ptur

ed a

nd u

sabl

e (c

alcu

late

d va

lue)

Col

umn

K:

The

daily

ave

rage

d so

lar

radi

atio

n ca

ptur

ed a

nd u

sabl

e on

an

equa

tor-

poin

ted

34°

tilte

d su

rfac

e (r

elat

ive

to t

he h

oriz

onta

l) (

colu

mn

E x

colu

mn

J)

Col

umn

L: T

he m

onth

ly a

vera

ged

sola

r ra

diat

ion

capt

ured

and

usa

ble

on a

n eq

uato

r-po

inte

d 34

° til

ted

surf

ace

(rel

ativ

e to

the

hor

izon

tal)

Col

umn

A:

Mon

th

Fa

rm #

1

Mo

nth



APPENDIX C – RETSCREEN RESULTS FOR SOLAR HOT WATER

Table 8. RETScreen Solar Hot Water Model for Farm #1

Technology

Load characteristicsApplication Swimming pool

Hot water

Unit Base case Proposed case

Load type OtherDaily hot water use L/d 3,360 3,360Temperature °C 82 82Operating days per week d 7 7

Percent of month used Month

Supply temperature method User-definedWater temperature - minimum °C 4Water temperature - maximum °C 4

Unit Base case Proposed case Energy savedIncremental initial costs

Heating MWh 111.6 111.6 0%

Resource assessmentSolar tracking mode FixedSlope ˚ 40.0Azimuth ˚ 0.0

Show dataDaily solar radiation - horizontal

Daily solar radiation - tilted

Solar water heaterTypeManufacturerModelGross area per solar collector m² 2.49Aperture area per solar collector m² 2.34Fr (tau alpha) coefficient 0.78Fr UL coefficient (W/m²)/°C 4.43Temperature coefficient for Fr UL (W/m²)/°C² 0.000Number of collectors 60 33Solar collector area m² 149.64Capacity kW 98.07Miscellaneous losses % 2.0%

Balance of system & miscellaneousStorage YesStorage capacity / solar collector area L/m² 70Storage capacity L 9,807.0Heat exchanger yes/no YesHeat exchanger efficiency % 98.0%Miscellaneous losses % 2.0%Pump power / solar collector area W/m² 15.00Electricity rate $/kWh 0.070

SummaryElectricity - pump MWh 3.5Heating delivered MWh 66.9Solar fraction % 60%

Heating system Project verification Base case Proposed case Energy saved

Fuel type Natural gas - GJ Natural gas - GJSeasonal efficiency 80% 80%Fuel consumption - annual GJ 502.2 201.0 GJFuel rate $/GJ 9.940 9.940 $/GJFuel cost $ 4,992 1,998

GlazedViessmann

Vitosol 100-F SV1

Solar water heater



APPENDIX D – FINANCIAL ANALYSIS DATA

Table 9. Financial Analysis Data for Farm #1

En

erg

y

Sa

ve

d

Co

st p

er

Un

it

of

En

erg

yA

nn

ua

l S

av

ing

s

Pre

sen

t V

alu

e

of

An

nu

al

Sa

vin

gs

En

erg

y

S

av

ed

C

ost

pe

r U

nit

o

f E

ne

rgy

An

nu

al

Sa

vin

gs

Pre

sen

t V

alu

e

of

An

nu

al

Sa

vin

gs

En

erg

y

Sa

ve

d

Co

st p

er

Un

it

of

En

erg

yA

nn

ua

l S

av

ing

sP

rese

nt

Va

lue

of

An

nu

al

Sa

vin

gs

En

erg

y

Co

nsu

me

d

Co

st p

er

Un

it o

f E

ne

rgy

An

nu

al

Co

sts

Pre

sen

t V

alu

e o

f A

nn

ua

l C

ost

sA

nn

ua

l

Co

sts

Pre

sen

t V

alu

e o

f A

nn

ua

l C

ost

s

(kW

h)

($/

kW

h)

($)

($)

(kW

h)

($/

kW

h)

($)

($)

(kW

h)

($/

kW

h)

($)

($)

(kW

h)

($/

kW

h)

($)

($)

($)

($)

AB

CD

EF

GH

IJ

KL

MN

OP

QR

S

00.

0358

$

-

$

23

9.27

$

0.

0900

$

-

$

60

1.77

$

0.

0802

$

-

$

535.

99$

0.09

00$

9.

65$

49

.55

$

161

80.

0365

$

22

.56

$

20

.51

$

61

80.

0918

$

56

.73

$

51

.57

$

61

80.

0818

$

50

.53

$

45.9

4$

9.

910.

0918

$

0.91

$

0.83

$

9.60

$

8.73

$

261

80.

0372

$

23

.01

$

19

.01

$

61

80.

0936

$

57

.87

$

47

.82

$

61

80.

0834

$

51

.54

$

42.6

0$

9.

910.

0936

$

0.93

$

0.77

$

-$

361

80.

0380

$

23

.47

$

17

.63

$

61

80.

0955

$

59

.02

$

44

.35

$

61

80.

0851

$

52

.57

$

39.5

0$

9.

910.

0955

$

0.95

$

0.71

$

9.79

$

7.36

$

461

80.

0387

$

23

.94

$

16

.35

$

61

80.

0974

$

60

.20

$

41

.12

$

61

80.

0868

$

53

.62

$

36.6

3$

9.

910.

0974

$

0.97

$

0.66

$

-$

561

80.

0395

$

24

.42

$

15

.16

$

61

80.

0994

$

61

.41

$

38

.13

$

61

80.

0885

$

54

.70

$

33.9

6$

9.

910.

0994

$

0.98

$

0.61

$

9.99

$

6.20

$

661

80.

0403

$

24

.90

$

14

.06

$

61

80.

1014

$

62

.64

$

35

.36

$

61

80.

0903

$

55

.79

$

31.4

9$

9.

910.

1014

$

1.00

$

0.57

$

-$

761

80.

0411

$

25

.40

$

13

.04

$

61

80.

1034

$

63

.89

$

32

.79

$

61

80.

0921

$

56

.91

$

29.2

0$

9.

910.

1034

$

1.02

$

0.53

$

10.1

9$

5.23

$

861

80.

0419

$

25

.91

$

12

.09

$

61

80.

1054

$

65

.17

$

30

.40

$

61

80.

0939

$

58

.04

$

27.0

8$

9.

910.

1054

$

1.05

$

0.49

$

-$

961

80.

0428

$

26

.43

$

11

.21

$

61

80.

1076

$

66

.47

$

28

.19

$

61

80.

0958

$

59

.20

$

25.1

1$

9.

910.

1076

$

1.07

$

0.45

$

10.3

9$

4.41

$

1061

80.

0436

$

26

.96

$

10

.39

$

61

80.

1097

$

67

.80

$

26

.14

$

61

80.

0977

$

60

.39

$

23.2

8$

9.

910.

1097

$

1.09

$

0.42

$

-$

1161

80.

0445

$

27

.50

$

9.

64$

61

80.

1119

$

69

.16

$

24

.24

$

61

80.

0997

$

61

.60

$

21.5

9$

9.

910.

1119

$

1.11

$

0.39

$

10.6

0$

3.71

$

1261

80.

0454

$

28

.05

$

8.

94$

61

80.

1141

$

70

.54

$

22

.48

$

61

80.

1017

$

62

.83

$

20.0

2$

9.

910.

1141

$

1.13

$

0.36

$

-$

1361

80.

0463

$

28

.61

$

8.

29$

61

80.

1164

$

71

.95

$

20

.84

$

61

80.

1037

$

64

.09

$

18.5

6$

9.

910.

1164

$

1.15

$

0.33

$

10.8

1$

3.13

$

1461

80.

0472

$

29

.18

$

7.

68$

61

80.

1188

$

73

.39

$

19

.33

$

61

80.

1058

$

65

.37

$

17.2

1$

9.

910.

1188

$

1.18

$

0.31

$

-$

1561

80.

0482

$

29

.76

$

7.

13$

61

80.

1211

$

74

.86

$

17

.92

$

61

80.

1079

$

66

.67

$

15.9

6$

9.

910.

1211

$

1.20

$

0.29

$

11.0

3$

2.64

$

1661

80.

0491

$

30

.36

$

6.

61$

61

80.

1236

$

76

.35

$

16

.62

$

61

80.

1100

$

68

.01

$

14.8

0$

9.

910.

1236

$

1.22

$

0.27

$

-$

1761

80.

0501

$

30

.97

$

6.

13$

61

80.

1260

$

77

.88

$

15

.41

$

61

80.

1122

$

69

.37

$

13.7

2$

9.

910.

1260

$

1.25

$

0.25

$

11.2

5$

2.23

$

1861

80.

0511

$

31

.58

$

5.

68$

61

80.

1285

$

79

.44

$

14

.29

$

61

80.

1145

$

70

.76

$

12.7

3$

9.

910.

1285

$

1.27

$

0.23

$

-$

1961

80.

0521

$

32

.22

$

5.

27$

61

80.

1311

$

81

.03

$

13

.25

$

61

80.

1168

$

72

.17

$

11.8

0$

9.

910.

1311

$

1.30

$

0.21

$

11.4

7$

1.88

$

2061

80.

0532

$

32

.86

$

4.

88$

61

80.

1337

$

82

.65

$

12

.29

$

61

80.

1191

$

73

.61

$

10.9

4$

9.

910.

1337

$

1.33

$

0.20

$

-$

2161

80.

0542

$

33

.52

$

4.

53$

61

80.

1364

$

84

.30

$

11

.39

$

61

80.

1215

$

75

.09

$

10.1

5$

9.

910.

1364

$

1.35

$

0.18

$

11.7

0$

1.58

$

2261

80.

0553

$

34

.19

$

4.

20$

61

80.

1391

$

85

.99

$

10

.56

$

61

80.

1239

$

76

.59

$

9.41

$

9.

910.

1391

$

1.38

$

0.17

$

-$

2361

80.

0564

$

34

.87

$

3.

89$

61

80.

1419

$

87

.71

$

9.

79$

61

80.

1264

$

78

.12

$

8.72

$

9.

910.

1419

$

1.41

$

0.16

$

11.9

4$

1.33

$

2461

80.

0576

$

35

.57

$

3.

61$

61

80.

1448

$

89

.46

$

9.

08$

61

80.

1289

$

79

.68

$

8.09

$

9.

910.

1448

$

1.43

$

0.15

$

-$

2561

80.

0587

$

36

.28

$

3.

35$

61

80.

1477

$

91

.25

$

8.

42$

61

80.

1315

$

81

.28

$

7.50

$

9.

910.

1477

$

1.46

$

0.14

$

12.1

8$

1.12

$

Col

umn

AYe

ar.

Col

umn

BA

nnua

l ene

rgy

that

can

be

save

d by

the

sol

ar t

herm

al s

yste

m p

er m

2 of

col

lect

or a

rea.

Col

umn

CC

ost

per

unit

of n

atur

al g

as in

$/k

Wh

esca

late

d at

2%

ann

ual i

nfla

tion.

Col

umn

DA

nnua

l off

set

savi

ngs

of n

atur

al g

as (

colu

mn

B x

col

umn

C).

Col

umn

EPr

esen

t va

lue

of a

nnua

l off

set

savi

ngs

(pre

sent

val

ue o

f co

lum

n D

).

Col

umn

FA

nnua

l ene

rgy

that

can

be

save

d by

the

sol

ar t

herm

al s

yste

m p

er m

2 of

col

lect

or a

rea.

Col

umn

GC

ost

per

unit

of e

lect

rici

ty in

$/k

Wh

esca

late

d at

2%

ann

ual i

nfla

tion.

Col

umn

HA

nnua

l off

set

savi

ngs

of e

lect

rici

ty (

colu

mn

F x

colu

mn

G).

Col

umn

IPr

esen

t va

lue

of a

nnua

l sav

ings

(pr

esen

t va

lue

of c

olum

n H

).

Col

umn

JA

nnua

l ene

rgy

that

can

be

save

d by

the

sol

ar t

herm

al s

yste

m p

er m

2 of

col

lect

or a

rea.

Col

umn

KC

ost

per

unit

of p

ropa

ne in

$/k

Wh

esca

late

d at

2%

ann

ual i

nfla

tion.

Col

umn

LA

nnua

l off

set

savi

ngs

of p

rpan

e (c

olum

n J

x co

lum

n K

).

Col

umn

MPr

esen

t va

lue

of a

nnua

l sav

ings

(pr

esen

t va

lue

of c

olum

n L)

.

Col

umn

NA

nnua

l ene

rgy

requ

ired

to

oper

ate

pum

ps,

incr

ease

d at

2%

ann

ually

for

"w

ear

and

tear

".

Col

umn

OC

ost

per

unit

of e

lect

rici

ty in

$/k

Wh

esca

late

d at

2%

ann

ual i

nfla

tion.

Col

umn

PA

nnua

l ope

ratin

g co

st o

f el

ectr

icity

(co

lum

n N

x c

olum

n O

).

Col

umn

QPr

esen

t va

lue

of a

nnua

l cos

t (p

rese

nt v

alue

of

colu

mn

P).

Col

umn

RA

nnua

l mai

nten

ance

cos

t ba

sed

on o

ne m

aint

enan

ce v

isit

ever

y 2

year

s, p

er m

2 of

col

lect

or a

rea.

Col

umn

SPr

esen

t va

lue

of m

aint

enan

ce c

osts

(pr

esen

t va

lue

of c

olum

n R

).

Ye

ar

Na

tura

l G

as

as

Pri

ma

ry F

ue

lE

lect

rici

ty a

s P

rim

ary

Fu

el

Pro

pa

ne

as

Pri

ma

ry F

ue

lM

ain

ten

an

ceE

lect

rici

ty

Off

set

Co

nsu

mp

tio

n

Documents

Solar-Thermal Feasibility Study Farm #1 Dairy Operation #1.pdf · Solar-Thermal Feasibility Study Farm #1 Dairy Operation Mirko Slivar Stantec Consulting Ltd. Suite 300 – 175 2nd