Renewable Energy Technologies

January 19, 2007

Canada is blessed with abundant energy sources, both conventional and renewable. Conventional energy sources will continue to be a large part of Canada's energy mix, but the share of clean renewable energy in that mix will continue to grow.

Renewable energy has been defined in many ways, but generally means fuel sources that produce usable energy without depleting resources, as is the case with fossil fuels, such as oil, gas and coal. Renewable energy is also characterized by low or zero-emissions of air pollutants or greenhouse gases. The main sources are water, biomass, wind, solar and earth energy.

Wind energy

The energy of the wind can be converted into mechanical energy or electricity. Wind energy is an infinitely renewable form of energy. It does not require fossil fuels, and it does not produce greenhouse gases or other air pollutants.

Though humans have used wind energy for thousands of years, modern wind technologies provide reliable, cost-effective, pollution-free energy for individual, community and national applications.

In good wind areas, the costs of generating electricity range between 5 and 10 cents per kilowatt hour — higher than traditional electricity generation but decreasing every year. Most conventional generation costs continue to increase.

As of November 2006, Canada's installed wind-energy capacity was 1341 megawatts, enough to power more than 400,000 homes. Each megawatt-hour of electricity generated by wind energy helps to reduce greenhouse gas emissions and other air pollutants that would otherwise be produced by fossil fuel-based generation.

Solar energy

There are many ways to transform sunlight into energy, but the main types are solar panels that convert sunlight directly to electricity (also called photovoltaic or PV panels), and panels that absorb heat from the sun and transfer it as space heating or water heating.

Solar energy has a number of advantages. It does not emit air pollutants or greenhouse gases. The energy from the sun is virtually unlimited and largely free once the initial cost of the installation has been recovered. Solar photovoltaic energy systems can be stand-alone or connected to a power grid.

Small-scale hydro

Hydro power uses energy from flowing water to generate electricity. Hydroelectric energy is Canada's main source of electricity, most of which comes from large projects developed by electric utilities.

Today, more small-scale hydroelectric projects are being developed. These smaller projects are often classified as small (1–30 megawatts), mini (100 kilowatts – 1 megawatt) and micro (100 kilowatts or less). Small-scale hydro projects take up little space and do not require the construction of dams, since the turbines are generally placed directly in the flowing stream.

Small-scale hydro can be a competitive source of clean, reliable energy. It is an especially a2007-09-05eration that currently provides electricity in most of Canada's remote communities.

Ocean energy

The generation of ocean energy draws upon mechanical energy from waves driven by winds, tides produced by the moon's gravitational pull as it orbits the earth, and thermal energy from the sun's heat stored in the ocean.

Canada's three coasts are endowed with immense ocean energy resources. This nascent clean-energy domain has the potential to help meet growing energy demands without producing greenhouse gases or other air pollutants.

Earth and geothermal energy

Two types of energy can be obtained from the earth — earth energy and geothermal energy.

Geothermal energy uses steam or hot water in the earth's crust to power turbines or to heat buildings or water. If the local geography has the right features, geothermal facilities can be installed to capture steam as it escapes from cracks or holes underground. Geothermal energy requires a source temperature of more than 100°C to drive a generating turbine.

Earth energy uses the relatively constant temperature of the earth below ground or below a body of water to cool or heat air and water for buildings. For example, a heat pump can extract heat from underneath the ground to heat a building. In the summer, the pump can be reversed to provide air conditioning by moving hot air out of the building and down into the ground.

There are thousands of earth-energy installations in Canada that are used for residential, commercial, institutional and industrial applications. Depending on the source of electricity used to run the system's components, an earth-energy system can reduce greenhouse gas emissions by more than two-thirds compared to similar systems that use fossil fuels.

Bioenergy

Bioenergy is produced by the release of chemical energy contained in fuels made from biomass. Biomass is stored solar energy in plants and many common waste products such as wastes from agriculture, forestry, municipal landfills and food processing. Biomass can supply heat, electricity and vehicle fuels such as ethanol and biodiesel.