Hydropower may not get as much attention as solar and wind get, but it’s actually America’s single largest renewable energy source. Hydropower currently produces six percent of the total energy needs of the U.S., and there is much potential to increase the electricity-generating capacity as a new report suggests. That’s because of the over 80,000 dams in the U.S; only 2,000 are producing power. Some of those not being used could be equipped for generation, and older facilities could be much more efficient with newer technology.