Electricity 101

How do we generate electricity? Basically it’s very simple. We spin a magnet surrounded by coils of copper wire and the constantly changing magnetic field causes the electrons in the copper wire to flow. In more technical terms, the magnet (or magnets) and the wire coils are collectively called a generator.

So, the next obvious question is how do we get the magnets to spin? Easy. We use a turbine, which is, in its simplest form, an axle with blades on it. When a fluid, like water, air or steam, pushes against the blades, the force causes the axle to rotate. This in turn spins the magnets.

Spinning the magnets and delivering the resulting electricity to customers contributed about $24.5 billion to Canada’s gross domestic product in 2009. In total, Canada generated 574.8 terawatt-hours of electricity in 2009, or enough electricity to power about 48 million average Canadian households.

Generating electricity in Canada is as diverse as the country itself. Most other countries rely on two or three sources of electricity, but Canada generates electricity from several energy sources – hydropower, natural gas, coal, nuclear power, fuel oil, wind power, biomass, tidal power and solar.

Hydropower, where water turns the turbines, is the most common method of generating electricity in Canada, and accounted for 362.9 terawatt-hours in 2009, or about 63.1 per cent of all the electricity produced in the country.

Conventional thermal powered electricity, where coal, natural gas, fuel oil or biomass is burned to create high-pressure steam that turns the turbines, accounted for 124.1 terawatt-hours, or 21.6 per cent of Canada’s electricity supply.

Nuclear electricity uses thermal energy from fission products to create high-pressure steam. About 86.2 terawatt-hours of electricity were produced 2009, about 15 per cent of Canada’s total generation.

Finally, wind energy generated 1.6 terawatt-hours of electricity in 2009, and combined with tidal, solar and fuel cell generated electricity, accounted almost 0.3 per cent of Canada’s electricity.

Solar generated electricity is one of two types of electricity that doesn’t require a turbine. Electromagnetic energy from the sun is converted directly to electricity by a photovoltaic (PV) cell. When the PV cell is exposed to electromagnetic radiation, the radiation is absorbed and electrons are emitted. Solar electricity is used primarily in residential applications and not in large-scale commercial applications.

The other type of electricity generated without a turbine is that produced from fuel cells. Fuel cells convert electrons stored in hydrogen to electricity by way of a chemical reaction without combusting the hydrogen. Full cells power objects ranging from small, hand-held devices to forklifts and transit buses.

Getting the electricity from the spinning magnets to the consumer is a two-stage process, transmission, which involves moving the electricity at high voltage from the point of generation to the area where it will be used, and distribution, which involves moving low voltage electricity from the transmission network to the actual point of consumption.

Once the electricity is generated, its voltage is boosted by step-up transformers to between 115,000 and 735,000 volts. This allows for more efficient movement of the electricity by reducing heat loss. There are more than 160,000 kilometres of high-voltage transmission lines in Canada, approximately 74,640 kilometres of which have voltages exceeding 230,000 volts.

For distribution to consumers, the voltage is lowered by step-down transformers at substations near the point of consumption. These transformers bring the voltage down to service level, typically 480 volts for industrial use and 120 or 240 for residential use.

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