In some states, maintenance costs are offset by tax breaks given to power plants that use renewable energy sources. There are many good sites for wind plants in the United States including California, Alaska, Hawaii, the Great Plains, and mountainous regions. Scientists say there is enough wind in 37 states to produce electricity from the wind. Generally, an average wind speed of 14 mph is needed to convert wind energy into electricity economically. The average wind speed in the United States is 10 mph.
Scientists use an instrument called an anemometer to measure how fast the wind is blowing.
An anemometer looks like a modern-style weather vane. It has three spokes with cups that spin on a revolving wheel when the wind blows. It is hooked up to a meter that tells the wind speed. As a rule, wind speed increases with altitude and over open areas with no wind breaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.