Wind energy has been used for centuries, for grinding grain, pumping water and generating electricity. Small wind turbines were an important source of electricity for rural families in North America in the 1920's and 1930's. Wind energy faded into the background with the rural electrification efforts of the 1940's and the development of reliable small engine generators.
Modern small wind turbines are technically advanced and reliable; incorporating permanent magnet alternators, sophisticated electronics, and innovative blade materials.
Wind And Solar
In many Canadian locations a wind turbine is an excellent supplement to a solar electric system. Small wind systems are often combined with photovoltaics because seasonal variations in wind and solar resources are complementary. Most places in Canada do not have adequate wind to use as a primary power source. Locations such as the prairies that have constant prevailing winds are most suited to wind power. Contrary to popular beliefs, coastal areas are not always the best sources of power as the winds are not constant and predictable such as the prairies.
Battery Size
In many Canadian locations a wind turbine is an excellent supplement to a solar electric system. Small wind systems are often combined with photovoltaics because seasonal variations in wind and solar resources are complementary. Most places in Canada do not have adequate wind to use as a primary power source. Locations such as the prairies that have constant prevailing winds are most suited to wind power. Contrary to popular beliefs, coastal areas are not always the best sources of power as the winds are not constant and predictable such as the prairies.
Site Selection
Wind flowing over the surface of the earth is slowed by the friction of the ground. Objects such as trees and houses create turbulence. This reduces the energy a turbine can extract from the wind and stresses on the turbine components. The higher a turbine is placed the more power is generated. A wind turbine should be at least 33 feet (10 meters) above any object within a 330 foot (100 meter) radius. Local geography also needs to be considered.
Wind Speed
The power of the wind is easy to feel and the sight of a wind turbine rotating in the wind provokes a lot of interest. Proper location is critical to the success of a wind turbine installation. The determining factor of a good location is the amount of wind that is available. If there is an average wind speed of 8 mph (13 km/h) or higher, wind power may be a viable source of electricity. The power available in the wind increases with the cube of the wind speed if the wind speed doubles the power available increases by eight!
Maintenance
Unlike photovoltaic modules, wind turbines have moving parts. Periodic maintenance of bearings, brushes and shafts is required. It is important when installing a wind generator to consider how easy it will be to access the generator and remove it.
Towers are a critical component of wind power systems. Proper location and height of tower are necessary to get maximum energy from a wind turbine. Improper tower design or installation may result in personal injury, property damage or a damaged generator and will very likely result in less than satisfactory performance from your wind turbine.
Fossil
Coal, oil and gas are called "fossil fuels" because they have been formed from the organic remains of prehistoric plants and animals.
Find out more about how they formed at www.energyquest.ca.gov/story/chapter08.html
At the time this page was written, they provided around 66% of the world's electrical power, and 95% of the world's total energy demands (including heating, transport, electricity generation and other uses).
Nuclear
Nuclear power is generated using Uranium, which is a metal mined in various parts of the world. The first large-scale nuclear power station opened at Calder Hall in Cumbria, England, in 1956. Some military ships and submarines have nuclear power plants for engines.
Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels.
Solar
We've used the Sun for drying clothes and food for thousands of years, but only recently have we been able to use it for generating power.
The Sun is 150 million kilometres away, and amazingly powerful.
Just the tiny fraction of the Sun's energy that hits the Earth (around a hundredth of a millionth of a percent) is enough to meet all our power needs many times over.
In fact, every minute, enough energy arrives at the Earth to meet our demands for a whole year - if only we could harness it properly.
Wind
We've used the wind as an energy source for a long time. The Babylonians and Chinese were using wind power to pump water for irrigating crops 4,000 years ago, and sailing boats were around long before that.
Wind power was used in the Middle Ages, in Europe, to grind corn, which is where the term "windmill" comes from.
Tidal
The tide moves a huge amount of water twice each day, and harnessing it could provide a great deal of energy - around 20% of Britain's needs.
Although the energy supply is reliable and plentiful, converting it into useful electrical power is not easy.
There are eight main sites around Britain where tidal power stations could usefully be built, including the Severn, Dee, Solway and Humber estuaries.
Only around 20 sites in the world have been identified as possible tidal power stations.
Hydro
We have used running water as an energy source for thousands of years, mainly to grind corn.
The first house in the world to be lit by hydroelectricity was Cragside House, in Northumberland, England, in 1878. In 1882 on the Fox river, in the USA, hydroelectricity produced enough power to light two paper mills and a house.
Nowadays there are many hydro-electric power stations, providing around 20% of the world's electricity. The name comes from "hydro", the Greek word for water.
Pumped Storage
Pumped storage reservoirs aren't really a means of generating electrical power. They're a way of storing energy so that we can release it quickly when we need it.
Demand for electrical power changes throughout the day. For example, when a popular TV programme finishes, a huge number of people go out to the kitchen to put the kettle on, causing a sudden peak in demand.
If power stations don't generate more power immediately, there'll be power cuts around the country - traffic lights will go out, causing accidents, and all sorts of other trouble will occur.
The problem is that most of our power is generated by fossil fuel power stations, which take half an hour or so to crank themselves up to full power. Nuclear power stations take much longer.
We need something that can go from nothing to full power immediately, and keep us supplied for around half an hour until the other power stations catch up. Pumped storage reservoirs are the answer we've chosen.
Wave
Ocean waves are caused by the wind as it blows across the sea. Waves are a powerful source of energy.
The problem is that it's not easy to harness this energy and convert it into electricity in large amounts. Thus, wave power stations are rare.
Geothermal
The centre of the Earth is around 6000 degrees Celsius - hot enough to melt rock. Even a few kilometres down, the temperature can be over 250 degrees Celsius.
In general, the temperature rises one degree Celsius for every 36 metres you go down.
In volcanic areas, molten rock can be very close to the surface.
Geothermal energy has been used for thousands of years in some countries for cooking and heating.
The name "geothermal" comes from two Greek words: "geo" means "Earth" and "thermal" means "heat".
Biomass
Wood was once our main fuel. We burned it to heat our homes and cook our food. Wood still provides a small percentage of the energy we use, but its importance as an energy source is dwindling.
Sugar cane is grown in some areas, and can be fermented to make alcohol, which can be burned to generate power. Alternatively, the cane can be crushed and the pulp (called "bagasse") can be burned, to make steam to drive turbines.
Other solid wastes, can be burned to provide heat, or used to make steam for a power station. "Bioconversion" uses plant and animal wastes to produce fuels such as methanol, natural gas, and oil. We can use rubbish, animal manure, woodchips, seaweed, corn stalks and other wastes.
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