Wind is everywhere, and it is pne of the planet’s most widely available sources of sustainable, renewable energy. It is a growing part of long-term strategies for large-scale power production. Small-scale wind power generators cause minimal environmental damage. And as the wind generator increases in efficiency, wind will likely be responsible for more of the power that we use every day.
The process of generating power from wind is simple. Wind blows across a propeller, mounted high enough to be above obstacles. This causes the propeller to turn. That turns a turbine, which drives a generator. The generator produces power, and a good windmill can produce about 2,300 kilowatt-hours per year.
On a small scale, wind generators are used to provide supplemental power in much the same way that smaller-scale solar panel installations are used. These are especially popular on farms and in rural-industrial areas where wind is plentiful and consistent. Much larger-scale installations, called wind farms, are also rising in popularity.
The largest land-based wind farm in the world was built between 2008 and 2009 near Roscoe, TX. It had a total construction cost of over $1 billion dollars, and with 627 turbines it now generates enough power for 250,000 households.
The largest off-shore wind farm in the world almost wasn’t finished. It was beset by financial challenges during its development, and the project changed hands numerous times. However, it was finally built and it now lies 7 miles off the coast of Thanet district in Kent, England. It covers approximately 13.5 square miles, cost about $1.4 billion, and adds 300 MW of power to the Kent grid.
There is plenty of criticism of wind power, especially the large-scale projects that cover vast areas of land or sea. Of these, the most common has to do with the unpredictability of wind. A windmill is expensive to build, and in order to be cost-effective it needs a high average wind velocity. However, winds change from day to day and from year to year. It is difficult to ensure that the infrastructure investment will pay off. And in fact, without subsidies wind production is rarely cost-effective.
Wind power is also ironically criticized for causing environmental damage. Although the production process doesn’t use any fossil fuels, large scale wind farms do take up an enormous amount of space. The areas that make good wind farms – rural zones with high average wind velocities -are often home to birds. Construction of the wind farm can upset their habitat, and once it is built the spinning blades can kill them. One company’s recent application to kill golden eagles in order to build a massive wind farm has drawn strong criticism from animal rights activists.
Still, most people would argue that all power production has some cost and that a wind generator in the right location holds the promise of producing clean energy for a long time. Large-scale wind farms are on the rise, and there is no reason to expect that to change. On a smaller scale, those who care about the environment, and those who just want to be free from the energy grid, will continue to look to wind power as an option as well.
Maria is an electrical engineer who specializes in wind generators.