Hydroelectric Power

Hydropower uses the energy of water movement to turn power turbines which generate electricity.  Hydropower does not require water specifically, but it requires the kinetic energy that is carried by rapid moving liquid, such as a river or a waterfall.  The amount of power that can be generated from moving water depends entirely on how fast it moves when it reaches the turbines.

Hydropower is normally harnessed through the use of giant dams. Large amounts of water are stored and then released in a controlled flow from the dam. The water depth increases pressure resulting in a large amount of kinetic energy in the outflow. The water is channelled to turbines that convert the kinetic energy into electricity. There are only three dams in the world today capable of generating over 1 gigawatts of energy. More countries are adopting this alternative power source with the United States alone owning more than 2,000 hydroelectric plants. As of 2012, China is the biggest user of hydropower, generating up to 20% of its electricity from hydroelectric sources.

Another method of using hydropower is through the use of pumping stations. Two reservoirs are located at different heights in from each other. When electricity production is required, water from the upper reservoir will flow to the lower reservoir.  During periods of low demand when electricity is cheap water is pumped from the lower reservoir to the upper reservoir in a kind of energy recycling.  Although more electricity is consumed pumping the water to the upper reservoir, it is economical as it is done during periods of low consumption.

Smaller hydroelectric plants can also harness the energy from the natural flow of rivers and streams.  Hydropower is a clean source of energy which is sustainable and beneficial to the environment. The only disadvantage is that it requires the water to move fast enough in order to generate large amounts of electricity.