If Iris has room on her roof for 35 solar panels rated at 270 W each that will generate, in total, 44,000 kWh per year. Cost: $52,000 to purchase and install the system. Electricity costs $0.18, and there is net metering for the entire amount. Calculate the time it takes for Iris to break even on her investment under the following conditions: Without any subsidy or SRECs. If SRECs sell for $250 / MWh . If there’s a 20% federal tax credit and a 10% state tax credit on solar residential installations and SRECs are selling as described earlier.