Hydropower is a renewable source of energy which uses the force or energy of moving water to generate power. The most common type of hydroelectric power plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity. But hydroelectric power doesn't necessarily require a large dam. Some hydroelectric power plants just use a small canal to channel the river water through a turbine.
Another type of hydroelectric power plant - called a pumped storage plant - can even store power. The power is sent from a power grid into the electric generators. The generators then spin the turbines backward, which causes the turbines to pump water from a river or lower reservoir to an upper reservoir, where the power is stored. To use the power, the water is released from the upper reservoir back down into the river or lower reservoir. This spins the turbines forward, activating the generators to produce electricity.
A small or micro-hydroelectric power system can produce enough electricity for a home, farm, or ranch.
Hydropower is the most advanced and mature renewable energy technology, and provides some level of electricity generation in more than 160 countries worldwide.
Hydropower plants range from very small to very large individual plants and vast integrated schemes involving multiple large hydropower plants.