The cost of a single solar panel lies in the range of $200 to $400, depending on the power output of the panel and the material it is made from. Before investing in equipping your home with solar power, it is wise to see whether the savings in the cost of electricity would justify the amount you would invest in the panels.

(a) Suppose your monthly electrical usage equals the national U.S. household average of 948 kWh. Assuming an average of five hours of sunlight per day and a 30-day month, calculate how many panels you would need to provide that amount of energy and what the total cost would be for each of the following two types of panels: (i) 140W panel that costs $210; (ii) 240W panel that costs $260. What is your conclusion?

(b) Suppose you decide to install the 240Wpanels, and the average cost of electricity purchased over the next three years is $0.15/kWh. What would the total cost savings be over that 3-year period? What more would you need to know to determine whether the investment in the solar panels would pay off? (Remember that a solar power installation involves batteries, AC/DC converters, wires, and considerable hardware in addition to the solar panels themselves.)

(c) What might motivate someone to decide to install the solar panels even if the calculation of Part (b) shows that the installation would not be cost-effective?