Guest Blog | January 4, 2013 | Energy Policy, Wind

Chances are, if you see a wind farm while driving on the road, you’re pretty certain what it is. Unlike coal or nuclear power plants, there’s usually little question as to what those big white spinning things are and what they’re doing. But, for whatever reason, you may find yourself looking for wind farms on Google Earth. Even though turbines are relatively easy to see and comprehend in three dimensions, when looking for turbines on Google Earth, finding turbines takes a bit of finesse and practice.

Wind farms usually have very little infrastructure built up near them – few large scale transmission substations, no huge piles of coal, no need to be near bodies of water. Also, wind turbines are frequently in “mixed-use” land zones, so the landscapes can be dominated by farmland, unassociated roads, landscapes, or even other power plants. These other uses can quickly distract the viewer and make it more difficult to find a wind turbine. Another limitation to finding wind turbines on Google Earth is their size compared to a coal or nuclear power plant. While coal and nuclear power plants tend to take up many, many acres of land and can be effectively viewed at several miles altitude, a Google Earth user will likely need to zoom in to about half a mile to get a clear image of a turbine. At half a mile, the resolution on Google Earth can get pixelated, making it harder to see a turbine. But, like the smokestacks from coal-fired power plants, the best way to identify a turbine is by its shadow on the ground.

As you can see, the landscape tends to dominate the shadows cast by the wind turbines at the Buffalo Mountain wind farm in Tennessee. The shadows are a function of the time of year (in this case, winter), position of the wind turbines, and time of day that the satellite imagery took the picture. Below is an image of a single turbine at the American Wind Power Center in Lubbock, Texas and a few turbine parts lying on the ground.