To create the database, the USGS partnered with the Department of Energy, Lawrence Berkeley National Laboratory and the American Wind Energy Association. The organizations merged their individual data sets to create a new database that was more accurate and comprehensive than previous efforts. Once they compiled the new database, researchers attempted to visually verify the precise location of each turbine using satellite imagery. They intend to update it periodically in the coming years as the wind industry grows.
The database shows that Kern County is home to some 4,581 wind turbines with a total power-generating capacity of somewhere north of 4,000 megawatts, giving Kern the largest county-level concentration of wind capacity in the nation. Put another way, there are more turbines in Kern County alone than in the entire Northeast region of the United States.
This image from the USGS's database shows the locations of hundreds of Kern County's wind turbines, lined up in diagonal rows.
California can also boast the No. 2 and No. 3 counties in the nation when it comes to turbine density: Riverside, home to the San Gorgonio Pass wind farm, and Alameda, where the Altamont Pass wind farm is located. Texas' Nolan County and Oregon's Gilliam County round out the top five.
At the other end of the spectrum, 2,501 counties are tied for dead last, with no commercial wind energy to speak of. There are a number of reasons for this, one of which is simple geography. There's a lot of variation in average annual wind speeds in the U.S., as shown the map below from the U.S. Department of Energy, which gives wind speeds at 80 meters, near the height of a typical wind turbine. The southeast, in particular, is virtually a wind desert relative to the rest of the country. As a result there are hardly any commercial wind projects to be found in the region.
Geography aside, there are also political considerations. Wyoming, for instance, stands out with a splash of deep purple on the map above. While it ranks seventh in the nation in terms of its potential wind-power generation, according to the Department of Energy, it ranks just 17th in terms of installed capacity. One factor driving the disparity: Wyoming is one of just two states that tax wind power (Oklahoma is the other), which renewable energy advocates say has stifled the development of the industry there.
Still, the cost of wind is falling to the point where interest in the industry is being driven more and more by plain economics, rather than political ideology. In 2015, the Department of Energy forecast that there will be over 400 gigawatts of installed wind-power capacity in the United States by 2050, representing more than a fourfold increase over our current 89 gigawatt capacity.