Wind

Windmills of one type or another have been around for well over a thousand years, and while they’ve improved greatly in efficiency, they still work pretty much the same way they always have.

In general, the taller the windmill and the stronger the wind, the more electricity it can generate. As the industry has matured, turbine capacities have grown from a few hundred kilowatts to many megawatts, with blade lengths (and thus tower heights) increasing accordingly.

The best areas for wind power in the United States are mostly in the Midwest, particularly in a broad band stretching from Texas to North Dakota. These regions are already largely built out or planned. New wind capacity is most likely to be installed in offshore farms, where the wind blows more strongly and consistently, but these are facing years of delays due to local opposition and high financing costs. Nevertheless, it is likely that offshore wind will eventually become a major contributor to energy supples.

A longstanding myth about wind power is that windmills kill large numbers of birds. While it is true that the bird is unlikely to survive a collision, such accidents are rare. Modern turbine blades spin slowly, and the birds can generally see and avoid them. Estimates of bird fatalities from wind turbines vary, but are typically under one million annually. That’s a tiny fraction of the more than 1 billion birds killed each year by domestic cats.