A house is kept at 22oC in the winter by means of electric heaters. On a cold day, the heaters are on for 18 hours and use an average power of 5 kW.
a. How much power would be saved if a heat pump with a COP of 2.0 was to be used instead?
b. Assuming the cold spell lasts a month (30 days), how much money would be saved by using the heat pumps instead of the heaters? Use $0.15/kWh.