The Folsom Powerhouse used the rushing waters of the American River to turn its turbines which its AC generators used to make AC electricity. This electricity was transmitted to Sacramento, more than 22 miles westward, via one of the lengthiest electrical distribution lines in the nation. At the time, the electricity produced by this powerhouse was perhaps the most economical electricity in the country.
The switch of the Folsom Powerhouse was flipped off in 1952 when the original Folsom Dam was demolished so that a larger dam could take its place. The newer dam has its own hydroelectric plant.