The deal requires Siemens to provide service and maintenance for 958 SWT-2.3 turbines at the projects for about 10 years.
Eight of the wind farms are already in operation, with the rest anticipated to start generation during the agreement.
The contract represents the largest onshore service deal to date for Siemens globally.
MidAmerican Energy and Siemens have worked together since 2008 in developing renewable energy resources in Iowa.
Siemens has a wind turbine blade manufacturing facility in Ft. Madison, where blades for several projects were produced.
Commenting on the agreement, Iowa Governor Terry Branstad said: "I am pleased that MidAmerican Energy and Siemens continue to find opportunities to work together to enhance our state’s position as a national leader in wind generation.
"It is great to see clean, renewable energy as the state of Iowa benefits from the quality jobs and positive economic impact that the renewable energy business generates and delivers."
Siemens Power Generation Services president and CEO Randy Zwirn said: "MidAmerican Energy continues to invest significantly in expanding and sustaining Iowa’s position as one of America’s leading producers of clean, renewable energy.
"We are extremely proud they have chosen Siemens to provide service and maintenance solutions to help ensure the optimal performance of these wind projects over the next decade."
Siemens presently provides service and maintenance for over 3,100 installed wind turbines in the Americas region and more than 7,600 worldwide, with a combined generating capacity of around 18GW.
Image: Siemens will provide service and maintenance to MidAmerican Energy’s 12 wind projects in Iowa. Photo: Courtesy of pakorn/FreeDigitalPhotos.net.
