Iowa Wind Projects Get Longer Life and Produce More Energy with Repowering

posted by Nathaniel Baer on Tuesday, August 22, 2017

Last week, the Iowa Utilities Board issued an order approving a proposal by MidAmerican Energy to re-power up to 1,000 megawatts of wind turbines in Iowa built approximately 10 years ago. Re-powered wind turbines generate more clean energy for Iowa and will do so far a longer period of time, compared to turbines that are not re-powered.wind

Under their repowering proposal, MidAmerican will replace the turbine blades with longer blades and will replace the nacelle with a more efficient design (the nacelle is the main mechanical component at the top of the turbine with the gearbox, generator, and other equipment). The existing tower will stay in place.

MidAmerican’s proposal is focused on GE wind turbines placed in service between 2004 and 2008. According to GE, repowering can increase energy output by up to 25% and extend the operating life of a turbine by 20 years. These are significant clean energy benefits with positive economic impacts. By generating more zero-fuel renewable electricity, MidAmerican can avoid using power plants that use fuel (coal, natural gas) and save on fuel costs. The repowering activity will occur in up to ten counties across Iowa, bringing economic benefits like local construction jobs and increased property tax revenue.

The Council actively supported the MidAmerican Energy proposal with written comments [NB1] in two dockets at the Iowa Utilities Board and in a workshop held earlier this summer, filed jointly with ELPC. We also joined a settlement on the proposal with MidAmerican, Google and Facebook. We applaud the Iowa Utilities Board for issuing the approval on a timely basis, which is important to access the federal production tax credit.

WindAs an early national leader in wind energy development, Iowa saw significant wind turbine construction in the late 1990s and early 2000s. As a result, we have more wind repowering potential than almost all other U.S. states, now that those early turbines are getting beyond 10 years of operation. Public policy supports repowering projects as well, given the availability of the federal production tax credit for qualifying repowering projects.

We look forward to seeing the repowered wind projects come on-line over the next several years and expanding Iowa’s national wind energy leadership.

Comments filed with the Iowa Utilities Board:




  1. wind power

About The Author

Nathaniel was with the Council as Energy Policy Specialist from 2007-2018. During his time with IEC,  he researched and advocated for policies to expand solar, wind, transmission and energy efficiency, and coordinated the Council’s coalition of allies on energy and climate issues.  ... read more