Hydro power is electrical energy produced through the power of moving water. Power obtained from the (typically gravitational) movement of water., Hydropower plants derive energy from the force of moving water and harness this energy for useful purposes. Traditional uses include watermills. In modern technology, hydropower moves turbines that pass on their energy to a generator which then produces electric power. Hydropower is a type of renewable energy, and once the power plant is constructed it produces little to no waste. Globally, hydropower contributes more electricity than any other renewable energy type.