As an energy-efficiency consultant, you’re asked to assess a pumped-storage facility. Its reservoir sits 146 above its generating station and holds…

As an energy-efficiency consultant, you’re asked to assess a pumped-storage facility. Its reservoir sits 146 above its generating station and holds 9.0×109 of water. The power plant generates 316 of electric power while draining the reservoir over an 7.6 period. Its efficiency is the percentage of the stored potential energy that gets converted to electricity.