Solar Energy at Macalester

 

Cost is an important factor to consider before implementing a solar energy system.  Several calculations can be made in order to determine the possible costs of installing a solar energy system.

The calculations shown below are for the Winton Health Services building at Macalester.  Winton was chosen because it is one of the lowest energy consuming buildings at Macalester.  Unfortunately, the energy consumption of Winton is still 5x more than the typical household, making it rather unfeasible as a potential site for solar energy.

 Winton Health Services

Winton Health Services

1998 Energy Consumption = 36,000 kWh/year = 100 kWh/day = 100,000 watt-hrs/day

bullet  Average of 4-6 good hours of sun per day in Minnesota
bullet  Assume 4 hrs of good sun per day for our calculations
bullet 100,000 watt-hrs / 4 hours = 25,000 watts PV needed
bullet 25,000 watts / 120 watt panel = 200 panels needed
bullet Size of panels: 56 inches x 26 inches (~10 sq. feet per panel) = 2,000 sq. feet roof space needed
bullet Estimated cost per panel:  $4 per watt  =  $480 per panel
bullet Total cost for panels = $100,000
bullet Additional hardware (power conditioning equipment, etc.) ~ $ 2 per watt ($50,000 total)
bullet Balancing system (mounting hardware, wires, labor, etc.) ~ $2 per watt ($50,000 total)
TOTAL COST 100% POWER = approximately $200,000
bullet Assuming a 25 year life for the solar panels, it will cost ~$8,000 per year for electricity   (~$0.20 per kWh) for Winton Health Services
bullet The Current Cost of Electricity @ Macalester is $0.05 per kWh is ~ $1,800 per year

 

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