Gov. Terry Branstad and MidAmerican Energy are announcing plans to spend $1.9 billion to install 656 wind turbines in Iowa by the end of 2015.
The Des Moines-based utility's plan announced Wednesday at a Statehouse news conference represents the largest economic development project in Iowa history.
When completed, the new turbines will have the capacity to generate up to 1,050 megawatts of wind power.
MidAmerican estimates that by January 2016, it will be capable of generating nearly 40 percent of its power by wind.
MidAmerican is Iowa's largest energy company, bringing electricity to 734,000 customers and natural gas to 714,000 customers in Iowa, Illinois, Nebraska and South Dakota.