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Hydroelectric energy

What is hydroelectric energy?

The energy contained in the natural flow of water in rivers can be transformed into usable energy. Early uses included converting the energy to mechanical power for activities like milling and sawing, and for irrigation. Hydroelectric energy is a renewable source of energy from which electricity is produced by extracting energy from flowing and falling water using a hydraulic turbine and an electric generator. Hydroelectric energy has been used to generate electricity for over a century and represents the world’s largest source of renewable electricity.

  • How is water converted into usable energy?

    Currently, hydroelectricity is the most common form of usable energy produced from flowing and falling water. To produce hydroelectricity, a turbine is placed in a body of moving water and converts the energy of flowing and falling water into mechanical energy that drives a generator, which generates electrical power. The amount of energy extracted from flowing and falling water depends essentially on the volume of water passing through the turbine per unit time (flow rate) and the change in water levels in rivers before and after the turbine (also known as head):

    • Hydroelectric stations are usually built at a sharp incline or waterfall to take advantage of the potential energy gained by the water as a result of gravity
    • Dams are built at some locations to help regulate the flow rate and head, and, therefore, the electricity generation
  • Hydroelectric energy in Canada

    Canada is the third largest producer of hydroelectricity in the world. All the hydroelectric stations in Canada generated a combined total of 393’789 gigawatt-hours in 2022, accounting for 61.7% of Canada’s total electricity generation. In 2021, Canada had 595 hydroelectric stations with 82’232 megawatts of installed capacity.

    Canada has many rivers flowing from mountainous areas toward its three bordering oceans. Hydroelectric stations have been developed in Canada where the geography and hydrography were favourable, particularly in Quebec. Other areas producing large quantities of hydroelectricity include British Columbia, Newfoundland and Labrador, Manitoba, and Ontario.

Hydroelectric Capacity (2010-2021, in megawatts)

Text version

The bar chart displays annual installations of hydroelectric energy capacity in Canada since 2010, in megawatts. The curve shows the increase in cumulative capacity installations from 75,062 megawatts in 2010 to 82’232 megawatts in 2021.

Hydroelectric energy research, development and demonstration (RD&D) at NRCan

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