- A homeowner paid $4000 for a solar water heater and received a tax credit of 30%. The system saves $450 per year. Find a simple payback time. Assuming a discount rate of 5%, find the payback time based on the Present Worth analysis.
- A solar power company plans to build a 50 MWe solar power plant with the following information. Find the LCOE and IRR for this investment.

Location: Daggett, California (Lat. 34° 51.8′)

Capital costs, including site prep and construction = $125 M (30%

equity, 70% debt at 5%)

Repairs and maintenance = $150,000/year (plant shutdown 10 days/ year for maintenance and repairs)

Yearly electrical output = 300 MWhe/day

Tariff received = $0.15/kWhe for the first year, with 5%/year escala- tion after that

Life of system = 25 years - Calculate the IRR(internal rate of return) if the power company gets a fixed feed-in tariff of $0.25/kWhe for 20 years and the salvage value of the plant after 20 years is $20 M.