Hydroelectric Power

HYDROELECTRIC POWER, also called hydroelectricity, is a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity. Far from being a new innovation, people have used this energy in nature for much of history, more than two thousand years ago people in Greece were using flowing water to turn the wheel of their mill to ground wheat into flour.

Most hydroelectric power plants have a reservoir of water, a gate or valve to control how much water flows out of the reservoir, and an outlet or place where the water ends up after flowing downward. Water gains potential energy just before it spills over the top of a dam or flows down a hill. The potential energy is converted into kinetic energy as water flows downhill. The water can be used to turn the blades of a turbine to generate electricity, which is distributed to the power plant’s customers.

As with all of the other categories within Saving Energy, there are lots of benefits of using hydroelectric power to create electricity – the fact that it’s renewable is just one of them. Hydroelectric power can be a very predictable and consistent form of electricity which works well with other forms of renewable energy to match demand. They’re actually one of the most flexible forms of generation, being able to hit maximum capacity in under 2 minutes and being able to be stopped just as quickly.

This means that hydroelectricity is perfect for helping meet any peak demands and balance generation throughout the day. Using hydroelectricity in combination with other more weather dependent renewable generation such as wind and solar is ideal as it can be turned on very quickly and is far more responsive than gas, coal or nuclear power stations.

Hydroelectric generators also have long lives when compared to other forms of electricity generation. A hydroelectric generator can still be in service 50 to 100 years of working and requires very little labour with low maintenance costs which makes a lot of economic sense.

Due to its efficiency in saving energy and its versatility, worldwide, hydroelectric energy is the most commonly-used renewable source of electricity – approximately 70% of all of the renewable electricity generated on Earth is from hydropower. China is the largest producer of hydroelectricity, and other top producers of hydropower around the world include the United States, Brazil, Canada, India, and Russia - Saving Energy is working with the organisations leading the way in projects which are supporting the further development of this important power source.


Water is about 800 times denser than the Air around you so even a slow flowing stream of water or moderate sea waves can yield considerable amounts of energy. There are many forms of water energy: