Also known as hydroelectric power, it is the most commercially developed renewable energy source. A large reservoir is created with dam that can control the flow of water. The flow causes a wheel to turn, which leads to the generation of electricity. Hydro energy can also be harnessed using the natural flow of a river. It can be used 24/7 and in any weather condition.
In the 1890s, Nikola Tesla developed a system of alternating current (AC) that enabled power from Niagra Falls to be generated and transmitted over great distances.
Hydroelectric power accounts for 6.3% of the energy generated in the U.S.