MidAmerican Energy Co. has selected Siemens Gamesa Renewable Energy as supplier and installer for the Rolling Hills wind power project—a 429-megawatt wind facility located in Adair, Adams and Cass counties in Iowa. The agreement marks the largest repowering order to date in North America.
Siemens Gamesa will use 163 SG 2.7-129 and 18 previously sold SWT-2.3-108 wind turbines. The repowering project includes replacement of the blades, hubs and nacelles for all units, as well as top tower sections for the SG 2.7-129 units. The nacelles and hubs will come from the Hutchinson, Kan., nacelle and hub assembly facility, and the blades will come from the Fort Madison, Iowa, blade manufacturing facility. Commissioning of the project is expected for late 2021.
Mortenson Renewable Energy Group built the Rolling Hills wind park in 2011 for MidAmerican Energy Co. The construction company was responsible for the erection of the wind turbines, the construction of access roads, foundations and underground collection. The wind park was one of the largest single-phase wind projects ever built in the U.S. Its power capacity generated electricity for 130,000 average households per year.