A homeowner in Santa Fe New Mexico is interested in having a

A homeowner in Santa Fe, New Mexico, is interested in having a solar PV system installed at his house. He would like the system to be able to cover all of his annual energy needs. The following is a table from his utility provider showing the monthly energy use in the household. His roof with solar access is facing due east at a 20 degree pitch with no shading. In addition, the local electric company is offering a rebate on residential solar installations of $2.00 per installed Watt, as well as a renewable energy credit rebate based on predicted system performance. The REC rebate is $2.50/W, which is then multiplied by the system performance. Since the installation is east facing, the predicted performance efficiency is 83% (with a system facing due south having a performance efficiency of 100%). Consumption Design system that will offset 100% of the home\'s consumption. Assuming $0.10/W electricity expense with a 5% annual inflationary rate increase, and a $7.50/W installed cost, what will the payback be for this system after the rebate from the utility provider? How do you wire the solar panel? Specifically, how many cells would you need and how would you wire them (series versus parallel) if the solar panel is to have a working voltage of 24.46 V and an amperage of 7.6 A? Assume the individual cells produce 98 V and 3.8 A.

Solution

Global average horizontal radiation in Santa Fe, New mexico = H= 6.49 kWh/m²/day

Tilt angle = 20^o

Total annual energy consumption = 8100 kWh

Total average annual horizontal radiation  in Santa Fe, New mexico = 6.49*365*(1+(cos(20)/2))*0.83 = 2367.32 kWh/m²

Area of solar panel = 8100/2367.32 = 3.4215 m²