The word ‘hydro’ comes from the Greek word for ‘water’. Ancient Romans use hydroelectric energy through turbines for thousands of years. Water mills provide another source for hydroelectric energy.

The first U.S. hydroelectric power plant was built on the Fox River in 1882 in Appleton, Wisconsin. This plant powered two paper mills and one home. Hydroelectric energy comes from flowing water … winter and spring runoff from mountain streams and clear lakes. Water, when it is falling by the force of gravity, can be used to turn turbines and generators that produce electric energy.

Definition of  Hydroelectric energy

A hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator converts this mechanical energy into electricity. The operation of a generator is based on the principles discovered by Faraday.


How do hydroelectric energy works?

  • Hydroelectric power comes from water at work, water in motion.

  • Hydroelectricity works by harnessing the potential energy of flowing water. 

  • Hydroelectric energy and coal-fired power plants produce electricity in a similar way.

  • A dam is built  on a large river that has a large drop in elevation.

  • The dam stores lots of water behind it in the reservoir.


How do hydroelectric energy works?

  • Near the bottom of the dam wall there is the water intake. Gravity causes it to fall through the penstock inside the dam.

  • At the end of the penstock there is a turbine propeller, which is turned by the moving water.

  • The shaft from the turbine goes up into the generator, which produces the energy.

  • Power lines are connected to the generator that carries electric energy.


Advantages of hydroelectric energy

  • Hydroelectric energy is a renewable energy.

  • Hydroelectric energy does not produce any green house gases.

  • The operation and maintenance cost of hydroelectric energy is low.

  • Design of hydroelectric energy generating plant is simple.

  • Hydroelectric energy plants have a very long life.

  • Although dams prevent the natural flushing out of a river during a flood, they also control flooding downstream in times of high rainfall and snowmelt.


Disadvantages of hydroelectric energy

  • Usually a large area of land has to be flooded to ensure a continuous flow of water to the turbine

  • Dams affect river ecosystems.

  • Constructions of hydroelectric energy plants are costlier.

  • An adequate supply of water from rain or snow is required for hydroelectricity plants to continue operation.


Interesting facts regarding hydroelectric energy

  • America’s leading source of renewable energy is hydroelectric energy.

  • Worldwide, hydroelectric energy accounts for about 20% of all electric generation.

  • Hydroelectric energy is very efficient energy source because some turbines can achieve efficiency of 95 % .


Interesting facts regarding hydroelectric energy

  • Hydroelectric energy today provides about 20 % of the world's electricity and is the main energy source for more than 30 countries.

  • Worldwide, water is the most commonly used renewable energy resource, providing enough energy to meet the needs of 28.3 million consumers.

  • Hydroelectric energy can also be used for water supply, flood control, irrigation and even recreation purposes..


Atomic energy Nuclear fusion
Definition of atomic energy Nuclear waste
What is atomic energy Wind energy
Atomic energy act Nuclear energy pros and cons
Atomic energy commission About nuclear energy
History of atomic energy Energy resources
Atomic energy definition Nuclear energy facts
Atomic energy levels Is nuclear energy renewable
Atomic energy symbol Nuclear reactors
What is atomic energy used for Nuclear technology
Geothermal energy How does nuclear power work
Tidal energy Atomic energy logo
Hydroelectric energy Types of energy


Air energy Light energy
Atomic energy Oil energy
Electric energy Sound energy
Gas energy Steam energy
Geothermal energy Sun energy
Hydro Energy Water energy
Kinetic energy Wave energy
Types of Energy    


Hydroelectric - Energy - - Power – Different – Various – All – Other – How Many – Renewal – Sources – Resources – Light – Electrical – Alternative – Chemical – Stored – Main – Kids – Children – Schools – Kinetic – Educational – Sun – List – Chart – Facts – Info – Information – Thermal – Nuclear – Wind – Mechanical – System – Basic – Conservation – Clean – Green – Solar – Natural – Definition – Units – Magnetic – Heat – Radiation – Radiant – Gravitational – Sound – Elastic – Nuclear – Microwave – Steam – Turbine – Water – Watt – Jewel – Internal – External – Combustion – Renewable - Transmission – Hydroelectric - Energy - Enegy - Hydrelecrtic - Hydrelectric