  
We were driving through North Dakota during the summer of 2002, and happened to notice a very tall windmill in a field near the road. We had never seen such a huge wind machine, and so of course we had to stop and have a look. What we saw was truly incredible ... the device was gigantic. We took some pictures, and when we got home, did some research on wind-generated power, and were amazed. Wind power generating devices have come a long way since the old windmill on the farm ... they are now part of the power-generating grid across North America. Wherever there is a lot of wind, there are windmills like this one, generating free, clean electricity. Have a look at the pictures we took, and then we'll tell you more about wind power.   
This wind-power generating device in North Dakota is 70 metres tall (about 230 feet), with 26 metre (85 foot) long glass-fibre blades. The whole thing weighs about 118 tonnes, and generates a whopping 2.5 million kilowatt-hours (kWh) each year. It does this without producing any pollution, and virtually for free. It starts producing electricity when the wind speed reaches 13 km/h, and cuts out if the wind speed reaches 90 km/h. It was put into operation in July of 2002. As we watched it, there was very little wind, but the blades were turning, almost silently, at about 15 rpm, quite an impressive sight. We took a short video of the windmill in operation, which you can download here. It's a 404k zipped file, so you'll have to save it and then unzip it before playing it. We think you'll be amazed too, at the size and power of the machine. We also have a large photo of the tower looking straight up .... have a look here. 
Apparently windmill 'farms' like the one near Palm Springs in the USA, shown at the right, are now quite common, especially in regions that don't have other cheap sources of power. In Canada, there are wind farms in Alberta, Saskatchewan, Quebec and Prince Edward Island.Pincher Creek, Alberta, has a number of large-scale wind projects ... visit one of them, Vision Quest. Wind power is now the world's fastest growing energy source. Canada in 2002 produced about 450 million kilowatt-hours of electricity - enough to supply about 56,000 typical Canadian homes. If this electricity were used to replace coal-generated electricity, it would prevent about 450,000 tonnes of carbon dioxide from being discharged into the atmosphere each year. If wind power were used to its full potential around the world, it is estimated that it would produce five times as much electricity as is currently being used world-wide! The cost of wind-produced energy, mostly due to the construction of the towers and electric turbines, is under 8¢ per kilowatt-hour for a large windmill farm.  Here's how a windmill works. Wind energy is a form of solar energy, created by winds in the Earth's
atmosphere that are driven by heat from the sun.
People have made direct use of wind energy for thousands of years, using sails on boats, or on windmills to grind grain.Nowadays, energy that the wind contains can be converted into electricity, using turbine generators. These work just like the generators at a hydro-electric power station, that harness the power of falling water to spin a rotor, driving an electric generator. In a windmill, the air flows past rotors that resemble airplane propellers, which spin and drive the shaft of an electric generator. The difference is that air is much less dense than water, and so the size of the rotor in a windmill must be much larger than the rotor of a hydro (water) turbine. However, wind energy is available over a much larger geographical area than water power ... about one-third of the U.S., for example, has enough wind almost everywhere to generate electricity economically. Wind turbines come in all sizes, from those with rotors measuring a few feet across (often used for battery charging on sailboats or vacation homes) to those with rotors hundreds of feet in diameter (used to generate "bulk" electricity that is fed into the utility transmission and distribution system across North America). Wind speed is important. The energy that the wind contains is a function of the cube of its speed. This means, for example, that if the wind in a location is twice as strong as somewhere else, it will generate eight times as much electricity. Wind energy is a nice way to generate electricity because it is pollution-free. More than half of all the electricity that is used in the U.S., for example, is generated from burning coal, which releases large amounts of toxic metals, air pollutants, and greenhouse gases into the atmosphere. If wind energy were to provide 20% of North America's electricity, it could help remove more than a third of the emissions from coal-fired power plants, or all of the radioactive waste and water pollution from nuclear power plants. Wind farms can also help the economy of rural communities, providing steady income to land-owners through lease payments by the wind-farm owners. Farmers can grow crops or raise cattle next to the towers, which use up only a very small portion of the land.  Others can also benefit by installing smaller windmills. In Spirit Lake, Iowa,
a school is earning income from the electricity generated by a turbine. In Forest City,
Iowa, a turbine which was built as a school project is expected to save $1.6 million in electricity costs over its lifetime.
Wind power projects in remote northern Canadian and Alaskan locations have shown that wind energy can reduce the high costs of transporting diesel fuel to these remote areas. Small wind turbines (under 100 kilowatts) like the one shown at the left are manufactured in Dartmouth in Nova Scotia, and in Guelph, Ontario. Greater use of wind energy in the future will mean a cleaner environment with healthier air, more income to economically depressed communities, and will mean we are relying more on an energy source that is is free and will never be exhausted or interrupted. |