
Among the renewable energy sources that produce electricity, hydropower is the most common one. It calculated for a 7 % of total U.S. electricity generation. It is among the oldest resource of energy and was used many years ago to revolve a paddle wheel for reason such as grinding grain. The first U.S. hydroelectric power plant opened on the Fox River near Appleton, Wisconsin, on September 30, 1882. Before that, coal was the solitary fuel used to produce electricity.







