Xcel Energy Inc., based in Minneapolis, says it has the most wind power on its system of any U.S. electric utility.
MidAmerican Energy Co., based in Des Moines, says it's the top utility in wind generation ownership.
The competing claims are both legitimate, and they underscore two distinct business approaches to harnessing wind power: To own or not to own?
MidAmerican owns almost all of its wind generation. Xcel, which has been getting power from the wind for nearly 20 years, purchases much of its renewable power under long-term contracts from wind farm developers.
There are pros and cons to each approach, as utilities weigh whether to tie up capital in wind technology or let others take the risks.
"Some utilities say that wind power is here, it's a viable option and I want to get it in my rate base," said Jeff Anthony, business development director for the American Wind Energy Association (AWEA), a trade group that tracks U.S. wind projects. "Other utilities feel, 'No, we don't quite know how to integrate an intermittent source.' "
Together, Xcel and MidAmerican Energy have a 17 percent share of the nation's wind power capacity. That's enough to power 2.5 million homes.
Most utilities have gone Xcel's way and bought renewable power from others under contracts. Industry officials say the companies didn't have any experience with wind power, especially in the 1990s, and turned to companies specializing in the technology.