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Hydroelectricity: Flowing water, flowing power

From rushing rivers deep in Canada's wilderness comes the electricity that keeps our cities humming. As a renewable, emissions-free source of energy, hydroelectricity is "green," but flooding from hydroelectric dams has sometimes devastated traditional aboriginal livelihoods. Ranging from a single tidal turbine to Niagara Falls to a dam carved from a mountain, Canada's hydro projects provide 60 per cent of this country's power.

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How does energy from a running river become a force that powers lights, refrigerators and other conveniences of modern living? The key is the water turbine: a large wheel-like object with internal blades that make the turbine rotate as water flows through. When the turbine is connected to a generator, it creates electricity. As a new power station goes up on the St. Lawrence River, the CBC children's program Junior Magazine demonstrates the process. 
• For a river to generate power, a series of structures must be built to transform its raw energy into electrical power:
- Dams hold back the river to create high water levels
- Reservoirs store water at high levels to maintain a steady supply
- Penstocks, or designated chutes, direct water into the turbines
- Turbines spin, powering electric generators in the powerhouse
- Power lines carry electricity from the powerhouse to your house

• Electricity is the energy that is created when subatomic particles (protons and electrons) vibrate against each other. The particles are attracted to those with the opposite charge and repelled by those with the same charge, creating energy.

• The "hydro" in "hydroelectricity" is derived from the Greek word for water. In Canada, hydroelectricity is so common that the word "hydro" is used to signify all electricity, whether it comes from water, coal or nuclear power.

• In 1995 about 60 per cent of Canada's electric power was derived from hydroelectric sources. That ranges from a high of about 85 per cent in British Columbia, Manitoba, Newfoundland and Labrador, Quebec and the Yukon to just four per cent in Alberta and none in Prince Edward Island.

• Other Canadian sources of electricity are, in order of usage: coal, nuclear power, gas and oil.

• Unlike most other sources of energy, hydroelectricity is renewable. Barring disastrous ecological changes, rivers will always flow to turn the turbines that create hydro energy.

• Renewable energy is that which will never be exhausted. Other examples are solar power, wind power and geothermal energy.

• Non-renewable energy is finite; once it's gone, it can't be recovered. Examples are fossil fuels such as coal, oil and gas, which will eventually be depleted.

• In 2002 the total generating capacity of hydroelectric plants in Canada was about 67,000 megawatts. "Generating capacity" means the amount that can be produced at any given time.

• Canada generates 353,000 gigawatt hours of electricity per year, making it the largest producer of hydroelectricity in the world.
Medium: Television
Program: Junior Magazine
Broadcast Date: May 11, 1958
Reporter: Doug Maxwell
Duration: 1:15

Last updated: November 6, 2014

Page consulted on November 6, 2014

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