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									Solar-Thermal Feasibility Study
Farm #3 Cherry Orchard




                                Mirko Slivar ● Stantec Consulting Ltd.
                         Suite 300 – 175 2nd Avenue, Kamloops, B.C.
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




                                     2
TABLE OF CONTENTS


1     EXECUTIVE SUMMARY ..................................................................................................... 4


2     SITE INFORMATION ........................................................................................................ 5


2.1     FARM OPERATION .......................................................................................................... 5
2.2     LOCATION .................................................................................................................... 5
2.3     EQUIPMENT .................................................................................................................. 5
2.4     UTILITY INFORMATION ................................................................................................... 5


3     THERMAL LOAD CALCULATIONS ...................................................................................... 6


3.1     CHILLED WATER ............................................................................................................ 6


4     SOLAR-THERMAL POTENTIAL .......................................................................................... 7


4.1     SOLAR HOT WATER ........................................................................................................ 7


APPENDIX A – MANUAL CALCULATIONS OF SOLAR POTENTIAL ............................................ 9




LIST OF FIGURES AND TABLES


Figure 1. Cherry Packing Process Flow Diagram .......................................................................... 5

Figure 2. Monthly Radiation – Incident and Usable for Farm #3 .................................................... 7

Table 1. Summary of Monthly Radiation – Incident and Usable for Farm #3.................................... 9

Table 2. Detailed Monthly Radiation Data for Farm #3 ................................................................10




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FARM # 3         SOLAR-THERMAL FEASIBILITY STUDY




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 at a cherry orchard and packing facility, located in the Okanagan
Valley.

The agricultural operation packs over 600 tons of cherries annually. The harvest season begins around
mid-July and lasts for about 6 to 8 weeks. Cherries are picked daily starting at first light and are
immediately taken to the packing facility where the fruit is cooled with cold water (8 to 10 C), hand
sorted, cooled further with cold water (4 to 7 C), sized, cooled even further with cold water (0 to 2 C),
then packed and stored at 1 C ready for shipment to market. Cooling cherries ensures the quality of
fruit from orchard all the way to market.

There is a potential for using solar-thermal chilled water at this fruit packing facility. Since the packing
facility only operates for 8 weeks in the summer it does not require heated air. Furthermore, other
than the bathroom sink, there is no requirement for hot water. Hence, there are no suitable
applications for using neither solar heated air nor solar hot water at this cherry packing facility.

The chilled water temperature demand for the cherry packing process starts at 10 C and goes down to
0 C in three steps. However, solar chilled water systems are limited to delivering down to a
temperature of 7 C, so only the initial cooling process when the cherries first arrive at the packing
facility is feasible.

The 20-ton chiller currently serving this process consumes about 25 kW of electricity under full load.
Based on the packing facility operation of 8 hours per day, 7 days per week, for 8 weeks, the unit will
run for 448 hours per season. With electricity rates at $0.084/kWh, the chiller will cost about $1,000
to operate annually.

To replace or supplement the cooling capacity of this chiller with solar will require at least 200 square
metres of collector area, according to solar chiller supplier Yazaki Energy Systems Inc. A solar chilled
water system will cost a minimum of $470,000. Based on a maximum savings of $1,000 per year, this
study concludes that a solar chilled water system is not a financially viable option for this cherry
packing facility.

Although there is no suitable opportunity to use solar-thermal systems for this agricultural operation,
this study looked at the solar radiation available at this site for solar hot water. Of the three
technologies explored in this study, solar hot water is the best use of solar energy per square metre of
installed collector area and represents the greatest potential for cost effective solar energy use.

For this site, the energy output from a square metre of south-facing collector is about 679 kWh
annually. About 71 per cent of this usable energy is received over the period April to October. Over
the other six months, the sun delivers the remaining 29 per cent of year's total usable energy.

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.




Stantec Consulting Ltd.                                                                           4
FARM # 3          SOLAR-THERMAL FEASIBILITY STUDY




2      SITE INFORMATION

The cherry harvest season in the Central Okanagan begins around mid-July and lasts for about 6 to 8
weeks. Cherries are picked daily starting at first light and are immediately taken to the packing facility
where the fruit is cooled with cold water (8 to 10 C), hand sorted, cooled further with cold water (4 to
7 C), sized, cooled even further with cold water (0 to 2 C), then packed and stored at 1 C ready for
shipment to market. The packing process starts around noon and finishes around 6 to 7 p.m. (refer to
Figure 1 for packing process flow). Cooling cherries ensures the quality of fruit from orchard all the
way to market.


    INCOMING          INITIAL STATION        SECOND STATION           THIRD STAGE
    FRESH             COOLING/SORTING        COOLING/SORTING          COOLING STATION           COLD STORAGE
    CHERRIES          WATER TEMP 8-10 C      WATER TEMP 4-7 C         WATER TEMP 0-2 C           AIR TEMP 1 C



Figure 1. Cherry Packing Process Flow Diagram

2.1       FARM OPERATION

The cherry orchard and packing facility packs about 600 to 650 tons of cherries annually.

2.2       LOCATION

          Kelowna, B.C.

          Latitude 49.5 degrees and longitude 119.5 degrees.

          This orchard, located in the Okanagan Valley, has good southern exposure to capture the sun
           with no shading issues from buildings, trees or mountains.

2.3       EQUIPMENT

          One 20-ton chiller Heat Craft model HDV200 to supply 8 to 10 C water.

          One 8.5 hp chiller Bohn model BZT086 to supply 4 to 7 C water.

          One 40-ton chiller Carrier model 30HR040544 to supply 0 to 2 C water.

2.4       UTILITY INFORMATION

Electricity is used in the packing facility for cold water process equipment, refrigeration, lights, hot
water and other electrical equipment. Space heating requirements are minimal since the building is
not used during the winter months. The operation does not use propane.




Stantec Consulting Ltd.                                                                           5
FARM # 3         SOLAR-THERMAL FEASIBILITY STUDY




3     THERMAL LOAD CALCULATIONS

There is a potential for using solar-thermal chilled water at this fruit packing facility. Since the packing
facility only operates for 8 weeks in the summer it does not require heated air. Furthermore, other
than the bathroom sink, there is no requirement for hot water. Hence, there are no suitable
applications for using neither solar heated air nor solar hot water at this cherry packing facility.

3.1    CHILLED WATER

The chilled water temperature demand for this packing facility starts at 10 C and goes down to 0 C in
the three steps previously described. Solar chilled water systems are limited to delivering down to a
temperature of 7 C, so only the initial cooling process when the cherries first arrive at the packing
facility is feasible.

The 20-ton chiller currently serving this process is a Heat Craft model HDV200, which consumes about
25 kW (based on manufacturer’s specifications) of electricity under full load. Based on the packing
facility operation of 8 hours per day, 7 days per week, for 8 weeks, the unit will run for 448 hours per
season. With electricity rates at $0.084/kWh, the chiller will cost about $1,000 to operate annually.

To replace or supplement the cooling capacity of this chiller with solar will require at least 200 square
metres of collector area, according to solar chiller supplier Yazaki Energy Systems Inc. A solar chilled
water system will cost a minimum of $470,000 ($360,000 for collectors, plus $50,000 for chiller, plus
$60,000 for buffer tanks, cooling tower and miscellaneous parts). Based on a maximum savings of
$1,000 per year, this study concludes that a solar chilled water system is not a financially viable
option for this cherry packing facility.




Stantec Consulting Ltd.                                                                           6
FARM # 3         SOLAR-THERMAL FEASIBILITY STUDY




4     SOLAR-THERMAL POTENTIAL

Although there is no suitable opportunity to use solar-thermal systems for agricultural operations at
this site, this section briefly presents the solar radiation available at this site for solar hot water. The
main feasibility study concludes that of the three technologies explored solar hot water is the best use
of solar energy per square metre of installed collector area and represents the greatest potential for
cost effective solar energy use.

4.1     SOLAR HOT WATER

It is not anticipated that an agricultural operator will perform these manual calculations. This method
is included for benchmarking and information purposes. The general procedure for carrying out these
calculations is:

      1) Determine monthly solar radiation available (refer to Appendix A).

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

For this case study, the energy input from the sun to a square metre of south-facing collector is about
1,526 kWh annually; and the energy output of a square metre of south-facing collector is about 679
kWh annually.

Figure 1 shows the monthly incoming radiation from the sun (green line) and the usable energy after
losses (red line). About 71 per cent of this usable energy is received over the period April to October.
Peak production for given collector occurs in July with 96 kWh per square metre of collector. In
December the collector is only able to produce 17 kWh per square metre of collector.




Figure 2. Monthly Radiation – Incident and Usable for Farm #3




Stantec Consulting Ltd.                                                                            7
FARM # 3         SOLAR-THERMAL FEASIBILITY STUDY




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 (about $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.

The collector selected in this example is a Viessmann flat plate collector (model Vitosol 100-F SV1).
Refer to the main feasibility study for a detailed discussion on solar fundamentals.




Stantec Consulting Ltd.                                                                        8
FARM # 3         SOLAR-THERMAL FEASIBILITY STUDY




APPENDIX A – MANUAL CALCULATIONS OF SOLAR POTENTIAL

Table 1. Summary of Monthly Radiation – Incident and Usable for Farm #3


                                      Farm #3


                          Incident Solar                  Usable Solar
  Month
              kWh/m 2-day        kWh/m 2-month kWh/m 2-month             %

     A               B                     C             D                E
    Jan            2.08                    64            24              37
    Feb            3.26                    91            39              43
    Mar            4.36                135               61              45
    Apr            5.19                156               75              48
    May            5.44                169               81              48
    Jun            5.56                167               80              48
    Jul            6.18                192               96              50
    Aug            5.83                181               87              48
    Sep            4.95                149               64              43
    Oct            3.32                103               38              37
    Nov            2.15                    65            18              28
    Dec            1.79                    55            17              30
                            2
                 kWh/m -yr:            1526             679              44
                   GJ/m 2-yr:              5.5          2.4              44
C olumn A: Month
C olumn B: The daily averaged solar radiation incident on an equator-pointed 34°
tilted surface (relative to the horizontal) (NASA data)
C olumn 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)
C olumn D: The monthly averaged solar radiation captured and usable on an
equator-pointed 34° tilted surface (relative to the horizontal)
C olumn 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 1,526
kWh annually; and the energy output of a square metre of south-facing collector is about 679 kWh
annually. The average annual operating efficiency of the collector (Viessmann flat plate model Vitosol
100-F SV1) is about 44 per cent. Results would be similar for other brands of flat plate collectors.




Stantec Consulting Ltd.                                                                        9
                                                                                                                                                                                                                                                                           FARM # 3




                                                                                                                                                                                                 data and operating




Stantec Consulting Ltd.
                                                                                                                                                                                                                                       Table 2. Detailed Monthly




                                                                                                                                                                                                 flat plate collector (model

                                                                                                                                                                                                 would be similar for other
                                                                                                                                                                                                 using NASA solar radiation
                                                                                                                                                                                                                                       Radiation Data for Farm #3




                                                                                                                                                                                                 Vitosol 100-F SV1). Results
                                                                                                                                                                                                 performance for Viessmann
                                                                                                                                                                                                 site specific and is calculated
                                                                                                                                                                                                 The monthly solar potential is




                                                                                                                                                                                                 brands of flat plate collectors.
                                                                                                                                                                                                 incident data, NRCan weather




                                                                                                                                       Farm #3


                                         Collector                               Average
                                                           Collector Heat                                            Collector Inlet                             Critical                              System          Daily System   Monthly System
                                          Optical                               Daytime Air        Incident Solar                               T                                  Factor
                           Month                            Loss Factor                                               Water Temp.                               Intensity                             Efficiency          Output          Output
                                         Efficiency                               Temp.

                                         Efficiency           W/m 2-C                  C            kWh/m 2-day              C                   C                W/m 2                               Efficiency        kWh/m 2-day   kWh/m 2-month
                              A               B                   C                    D                   E                 F                   G                   H                 I                   J                  K                                     L
                                                                                                                                                                                                                                                                        SOLAR-THERMAL FEASIBILITY STUDY




                             Jan             0.694              4.452                -0.5                 2.08               20                20.5                263.0             0.13                0.37                0.77                              24
                             Feb             0.694              4.452                 1.0                 3.26               28                27.0                346.4             0.11                0.43                1.40                              39
                             Mar             0.694              4.452                 8.2                 4.36               42                33.8                433.7             0.10                0.45                1.96                              61
                             Apr             0.694              4.452                13.3                 5.19               51                37.7                483.7             0.09                0.48                2.49                              75
                             May             0.694              4.452                18.1                 5.44               56                37.9                486.3             0.09                0.48                2.61                              81
                             Jun             0.694              4.452                21.6                 5.56               62                40.4                518.3             0.09                0.48                2.67                              80
                              Jul            0.694              4.452                25.0                 6.18               64                39.0                500.4             0.08                 0.5                3.09                              96
                             Aug             0.694              4.452                25.0                 5.83               64                39.0                500.4             0.09                0.48                2.80                              87
                             Sep             0.694              4.452                19.4                 4.95               62                42.6                546.6             0.11                0.43                2.13                              64
                             Oct             0.694              4.452                11.6                 3.32               48                36.4                467.0             0.14                0.37                1.23                              38
                             Nov             0.694              4.452                 4.0                 2.15               37                33.0                423.4             0.20                0.28                0.60                              18
                             Dec             0.694              4.452                -0.8                 1.79               26                26.8                343.8             0.19                 0.3                0.54                              17
                          C olumn A: Month
                          C olumn B: Optical efficiency is the fraction of solar radiation which passes through the outside collector glass and reaches the absorber and is actually absorbed for a Viessmann flat plate collector
                          C olumn C : C ollector heat loss factor is a property of the collector chosen
                          C olumd D: Average monthly daytime temperature (NRC an data)
                          C olumn E: The daily averaged solar radiation incident on an equator-pointed 34° tilted surface (relative to the horizontal) (NASA data)
                          C olumn F: Approximate average fluid temperature entering the collector (calculated value)
                          C olumn G: Temperature difference between fluid entering collector and average daytime temperature (column F - column D)
                          C olumn H: The critical intensity is indicative of the length of time in each day during which the collector produces energy (calculated value)




10
                          C olumn I: This factor is an extension of column H and involves the critical intensity and the period of collector operation (calculated value)
                          C olumn J: The percentage of incident solar radiation captured and usable (calculated value)
                          C olumn K: The daily averaged solar radiation captured and usable on an equator-pointed 34° tilted surface (relative to the horizontal) (column E x column J)
                          C olumn L: The monthly averaged solar radiation captured and usable on an equator-pointed 34° tilted surface (relative to the horizontal)

								
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