Green power is energy from renewable resources - such as solar, wind, geothermal, small hydro, and biomass - which are a lot less harmful to our environment than conventional energy sources like coal, oil, gas or nuclear power.
Fossil fuels and nuclear plants contribute to some of the worlds greatest environmental problems, including global climate change, smog, acid rain, oil spills and dangerous radioactive waste.
It doesn't have to be like this. We can meet our energy needs and ensure the health of our planet for now and for future generations. But it will take a radical change in the way we generate and use energy - an energy revolution.
While not strictly a 'source' of energy, conservation is a key part of the green energy solution, as the greenest form of energy is to not use it in the first place.
Using less energy doesn't mean shivering in the dark. It means getting the most out of the electricity and gas we consume by taking steps to cut down on energy waste and be more energy efficient. And it can help you cut your fuel bills while creating green jobs!
Easy ways to save energy include:
- Turn down your heating or air conditioning and dress appropriately.
- Put compact flourescent light bulbs in your four most-used lights - they produce the same amount of light for about a quarter of the energy of ordinary light bulbs and last much longer.
- Switch off lights and appliances when not in use.
- Use cooler wash temperatures and full loads in washing machines.
- In Toronto, contact Green$aver for a home or small business energy audit.
The wind is a source of clean, renewable energy. Wind turbines (windmills) use strong, steady wind to create electricity. Wind power emits no pollution and has very little impact on the land. Wind energy can be produced anywhere the wind blows with consistent force. The windier the location, the more energy that can be produced, and the lower the cost. Good sites for wind power are located widely throughout the Ontario and the world. Wind farms can also be mixed with agricultural farms, as only about 5% of the land where a wind farm is sited is actually occupied by turbines, equipment, and access roads - the rest can be used for growing crops or grazing livestock.
Wind energy produced in California now provides for the residential needs of more than one million people. The Canadian Wind Energy Association's Wind Vision for Canada outlines how Canada can install 10,000 MegaWatts of wind power by 2010 - enough to power 4 million homes. Contact the Windshare cooperative to find out how you can get involved in wind power development in Toronto.
Small Hydro (run-of-the-river)
Hydropower facilities intercept the water as it flows down rivers and streams, converting its mechanical energy into electricity. Hydropower is considered a renewable energy resource, but not all hydro is green. The construction and operation of large hydropower dams impact natural river systems and fish and wildlife.
Small-scale, run-of-the-river hydro projects are, however, usually considered "green." Run-of-river projects typically use relatively low dams where the amount of water running through the powerhouse is determined by the water flowing in the river. Because these plants generally do not hold back water behind storage dams, they tend to have less effect on upstream water levels and downstream stream flow than storage projects. Electricity generation from these plants will vary with changes in the amount of water flowing in the river.
The sun's radiation is used in two ways: photovoltaic (PV) systems and solar thermal systems. PV systems change sunlight directly into electricity. PV panels are commonly used in areas where it is cheaper than running electrical wires or using batteries, including: rural homes, remote research stations, freeway call boxes, or solar-powered calculators. Solar thermal systems use the sun's energy to heat spaces or water; for example, by running liquid through a solar hot water heater (basically a long black tube on your roof that runs down to your hot water heater) to pre-heat the cold water in the tank, you can cut your gas or electricity consumption for water heating in half.
Passive solar energy - using building design to help heat or cool buildings - is also an important element of the green energy revolution.
Bioenergy is produced by the release of stored chemical energy contained in fuels made from biomass. Biomass is actually a product of solar energy that has been stored by the photosynthetic activity of plants. The plants remove CO2 from the atmosphere and combine it with water to produce biomass.
Biomass is in many common waste products, such as agricultural or forest waste (such as straw or sawdust left over from sawmills).
Bioenergy is not a new concept. It is one of the oldest of all energy resources, beginning with the controlled use of fire to provide heat, light and cooking for earliest mankind.
Today, 5.9% of Canada's primary energy demand is supplied from the combustion of biomass. Other countries that are not heavily industrialized or do not have indigenous fossil fuels still use biomass for a large portion of their energy supply.
A promising source of energy for Toronto is to capture the methane gas from the City's green bin program, sewage plants and landfills as organic matter decomposes and burn it to produce heat and electricity. By converting this naturally-occuring methane into carbon dioxide, we reduce its contribution to global warming by over 90 percent.
There are two types of energy that can be obtained from the earth:
Earth energy uses temperatures found in the earth or below 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. Toronto's deep lake water cooling project - which takes cold water from deep in Lake Ontario and uses some of this cold energy to cool office buildings before the water goes to be treated for use as drinking water - eliminates the need for electricity to run air conditioners and is less disruptive to the lake ecosystem (coal or nuclear electricity generating stations release large amounts of hot water into the lake from the steam used to turn tubines).
Geothermal energy is generated by converting the hot water or steam from deep beneath the Earth's surface into electricity. Geothermal plants emit very little air pollution and have minimal impacts on the environment. They are very economical, competing favorably with fossil fuel generation. Currently, geothermal plants in the U.S. provide enough electricity to supply the homes of 3.5 million people, but there is limited geothermal potential in Ontario.