Definition of Hydroelectric Energy

Hydroelectric energy is energy derived from the movement of water.

Water has mass. It falls and flows downward due to gravity. When it moves, it has kinetic energy which can be harnessed. Kinetic energy is the energy of motion.

How is hydroelectric energy harnessed?
In order to harness hydroelectric energy, a power plant needs to be installed in an area with flowing water. This may include a dam that blocks or diverts water. It may also include one or more reservoirs.

What is hydroelectric energy used for?
Hydroelectric energy is used for electricity generation accounting for 6% of all U.S. generation as of 2008. It is the most widely used sustainable source of energy.