The best sites for hydropower dams have already been developed so the development of big hydro plants is unlikely. But existing plants could be enlarged to provide additional generating capacity. Plus, many flood-control dams not equipped for electricity production could be outfitted with generating equipment. The Federal Energy Regulatory Commission estimates 60 thousand megawatts of additional generating capacity could be developed in the United States. People use more electricity during the day when they are awake and using electrical appliances, and less at night when they are asleep.
People also use more electricity when the weather is very cold or very hot.
Electric utility companies have to produce electricity to meet these changing demands. Baseload power is the electricity that utilities have to generate all the time. For that reason, baseload power should be cheap and reliable. Hydropower meets both these requirements. Generating, electricity from flowing water is the cheapest way to generate electricity in the United States, and the fuel supply-flowing water is always available, especially at plants with pumped storage systems.