In this problem, we consider replacing an existing electrical water heater with an array of solar panels. The net installed investment cost of the panels is $1,680 ($2,100 less a 20% tax credit from the government). Based on an energy audit, the existing water heater uses 180 kilowatt hours (kWh) of electricity per month, so at $0.13 per kWh, the cost of operating the water heater is $23.4 per month. Assuming the solar panels can save the entire cost of heating water with electricity, answer the following questions. a. What is the simple payback period for the solar panels? b. What is the IRR of this investment if the solar panels have a life of 10 years? A computer call center is going to replace all of its incandescent lamps with more energy efficient uorescent lighting xtures. The total energy savings are estimated to be $1,581 per year, and the cost of purchasing and installing the uorescent xtures is $4,700. The study period is seven years, and terminal market values for the xtures are negligible. a. What is the IRR of this investment? b. What is the simple payback period of the investment? C. Is there a conict in the answers to Parts (a) and (b)? List your assumptions. d. The simple payback "rate of return" is 1/6. E> a. The IRR of the investment is 27.50 %. (Round to one decimal place.) b. The simple payback period of the investment is 3 years. (Round up to the next whole number.) c. Select all the correct assumptions below. _ A. The IRR will signal an acceptable (protable) project if the MARR is higher than 27.5%. |n."B. The value of 6 may indicate a poor project in terms of liquidity. C. The value of 6 may indicate the best project in terms of liquidity. In." D. The IRR will signal an acceptable (protable) project if the MARR is less than 27.5%. cl. The simple payback "rate of return", 1/6, is D%. (Round to one decimal place.)