4. (20 pts) A wind turbine rated at 5 MW operates at a capacity factor of 0.38. The installed cost of the turbine is $6,000,000. The electricity can be sold for $0.10/kWh. The turbine was paid for with a down payment of 20% of the cost and a loan for the balance. The interest rate on the loan is 5% and the loan period is 15 years. The annual operation and maintenance amounts to 2% of the capital cost. General inflation is 3% per year and the discount rate is 4% per year i) What is the simple payback period? ii) What is the annual payment on the loan? iii) What is the present value of the sum of all the costs and revenues in the 10th year (only the 10th year, not the others)? Assume that revenue and O&M costs are both affected by the same inflation rate