What is Hydroelectric Power?

Hydroelectric power uses falling water.

The Origin of Hydro Power

Hydro Power was first used in Ancient Egypt. They used flowing water to make a machine work and grind their crops.

The History

The first recorded use of hydro power was a clock. It was built in 250 BC. The first hydro electric power plant was at Niagara Falls, in Canada. The early hydro-electric power plants were much more reliable than the fossil fuel plants. There was a high electricity demand in the middle years of this century.

The Size

Hydro power plants today range in size from several hundred kilowatts to several hundred megawatts. Some of the larger plants have capacities up to 10,000 megawatts and supply electricity to millions of people.

How It Works

Water is needed to run a hydroelectric unit. The force of the water being released through the dam spins the blades of a turbine. The turbine is connected to a generator. The generator produces electricity. When ever the water is done going through the turbine, the water go back to the river.

The Production of Power from Hydro Energy

Step 1 :A hydroelectric power plant uses the force of falling water from a reservoir to turn a turbine that drives a generator.
Step 2 :An exciter powers the rotator.
Step 3 :As the rotator and its magnetic field turn, an electric charge is created in the stator.
Step 4 :A transformer increases the voltage of the current coming from the starter.

The Advantages

The Disadvantages

  • Hydropower plants have a Long life and low operating cost. It is also clean, domestic and renewable source of energy. In hydropower plants the source of energy is not destroyed unlike fossil fuel electricity.
  • Hydropower plants have high set up cost, long construction period and flooding. They can also affect fish and wildlife habitats.

Types of Hydropower Plants

Most of the hydropower plants are conventional in their design. They usually use one-way water flow to make electricity.


Run-of-river plants: They use a little of stored water to make the water flow through the turbines. A lot of these types store water for up to 1 week. Changes in the weather have to do with many of the power outages.

Storage Plants: These types have enough water stored to provide a constant supply of electricity. The large dams can store several years worth of water

Pumped Storage

This types reuses water. After water produces the electricity, it goes from the turbines to a reservoir located below the dam.

The Impact of Hydropower plants on the Environment

Hydropower is one of the cleaner types of electricity. It prevents the burning of 22 billion gallons of oil or 120 million tons of coal each year. Hydropower does not produce air pollution. Hydropower has no waste.

Building Hydropower Plants

Dams and reservoirs provide flood control, water supply, irrigation, transportation, recreation and refuges for fish and birds. although not as many as government agencies.

The Life Span

Some hydropower live up to 200 years.

Interesting Facts...

About 20% of all electricity is generated by hydropower. Hydropower provides about 10% of the electricity in the USA. Norway produces 99% electricity with hydropower. New Zealand uses 75%. Only 2,400 of the nation's 80,000 existing dams are used to generate power.

Where It Is Used In Canada

Hydro power is mainly used in Quebec, Ontario and British Columbia.

The Largest Hydroelectric Power Plants in the World.


1. Turukhansk-USSR-1994-20,00,000

2. Itaipu-Brazil/Paraguay-1983-12,600,000

3. Grand Coulee-USA-1942-10,830,000

4. Grui (Raul Leoni)-Venezuela-1968-10,300,00

5. Tucurui (Raul G. Lhano)-Brazil-1980-7,960,000

6. Sayano-Shushensk-USSR-1990-6,400,000

7. Corpus Posadas-Argentina/Paraguay-1984-6,000,000

8. Krasnoyarsk-USSR-1968-6,000,000

9. La Grand 2-Canada-1979-5,328,000

10. Churchill Falls-Canada-1971-5,225,000


Swift flowing rivers or streams, mountain regions or areas with heavy rainfall are the best sites for hydroelectric plants.


Hydropower is the most efficient way to generate electricity. With in the last 10 years the Department of Energy has spent $1.2 billion on research and development for other renewable sources like wind, solar, and geothermal. They only $10 million on hydropower.

On of the most famous hydropower plants in Canada is Niagara Falls

Click here to go to a web-site on Niagara Falls