Interactive: Powering the Nation with Wind
By David Kroodsma
How much electricity could the U.S. generate from wind turbines? The answer may surprise you. For example, Texas alone could provide more electricity using wind energy than the entire United States currently uses.
Click through this graphic above and you’ll see just how far we are from fully utilizing this vast resource. Only five states (Washington, West Virginia, Pennsylvania, Tennessee, and Utah) have installed more than one percent of their potential wind energy generation. As a nation, we’re using only about 0.2 percent of our country’s potential wind resource.
It's also clear where this resource lies: in the Great Plains. The top states for potential wind power are Texas (see above), as well as Kansas, Nebraska, South Dakota, Montana, North Dakota, and Iowa. Any one of these latter six states alone could produce more than half as much electricity per year as the nation uses.
On the flip side, the Southeast is relatively wind energy free, and some states, such as Alabama, have effectively zero potential for wind generation. That doesn’t mean it’s never windy in Alabama — it just means that the wind doesn’t blow strongly or consistently enough for wind turbines.
The Northeast and Midwest have somewhat more potential, largely because of stronger winds that blow across the Great Lakes or along the Atlantic coast. The Western states, likewise, fare reasonably well.
The map below, produced by the U.S. Department of Energy, displays how average wind speed varies across the country, showing clearly just how wind-rich the middle of the country is.
The numbers in the clickable graphic above were estimated using data from the National Renewable Energy Laboratory (NREL) in Colorado, and AWS Truepower of Albany, New York, based on detailed wind-speed data. For the onshore data, they excluded areas such as national parks, wilderness areas, cities, wetlands, or steep mountainsides. The offshore estimates include the strip of ocean extending 50 nautical miles from shore as well as the U.S. portion of the Great Lakes.
Of course, even though there is enough potential wind energy to power the nation more than 10 times over (12, to be exact), in practice we can’t currently rely on wind alone. The strong breezes don’t always blow and we don’t yet have cheap ways to store vast amounts of energy, not to mention that our electricity transmission system needs to be considerably beefed up to be able to move wind electricity from windy areas to places that would use the electricity.
Other notes on the data sources:
The onshore dataset estimated wind potential at 80 meters off the ground, while the offshore data are for 90 meters. Both estimates assume 5 megawatts of wind turbine capacity installed per square kilometer of area over which the average wind speed meets a threshold of 6.5 meters per second onshore and 7 meters per second offshore. Additionally, an average annual capacity factor of 30 percent was used to convert potential installed capacity into potential electricity generation. (The annual capacity factor is the amount of electricity a turbine produces over a year divided by the electricity it would have produced if the wind had blown hard enough 24/7/365 to run the turbine at its full rated capacity.)
The current electricity production for each state comes from the U.S. Energy Information Administration's (EIA) Electric Power Monthly, which reports the total wind power produced in 2010. Wind power, though, is growing quickly, and these numbers are likely already outdated because more turbines have been installed — according to the EIA, U.S. wind capacity increased 40 percent per year from 2005 to 2009.
The percent of U.S. electricity use that the potential wind power in each state could provide is calculated assuming that the U.S. uses 3,950,000 Gigawatt-hours of electricity per year, the national consumption level in 2009, according to the EIA.
Finally, for the number of homes that each state could power with wind energy, we used the EIA’s Residential Energy Consumption Survey for 2005, which estimates that the average U.S. home uses about 11,500 kilowatt-hours of electricity per year.