Siemens Gamesa announced Wednesday it signed a contract to provide 21 of its new 4.5-megawatt wind turbines for a wind farm expansion project in Iowa.

It’s at least the fourth contract the company has signed this year for the turbine, its largest on-shore product, to be supplied by the company’s manufacturing plant in Hutchinson.

MidAmerican Energy Company is buying the nacelles for its 95-megawatt Southern Hills Expansion wind power project, which will feature the turbines operating at 4.8 MW.

The SG 4.5-145 features a 71 meter or 233-foot long blade.

The contract also includes the company’s premier service and maintenance agreement for three and a half years.

The model is designed for sites with medium winds, the company stated in a release, offering a flexible generation rating between 4.2- and 4.8 MW, which makes it adaptable for optimal performance at each individual project.

“We are once again proud to have been awarded a project by MidAmerican Energy Company, strengthening our long-standing relationship with them,” stated José Antonio Miranda, CEO of Onshore Americas at Siemens Gamesa Renewable Energy, in the release. “We have had great success with the SG 4.5-145 wind turbine, with over 1.4 GW sold in the U.S., Canada and Mexico, and are excited to continue growing that number.”

The company announced its first three contracts for the new 4.5-megawatt turbine made in Kansas in June. Those contracts were with EDF Renewables for 30 turbines in Milligan County, Neb., 48 turbines for the 241 MW Coyote wind project in Scurry County, Texas, and 48 SG 4.5’s for the 246 MW Oso Grande wind project in New Mexico.

Siemens Gamesa has installed nearly 1,400 wind turbines in Iowa, for a total of almost 3.5 gigawatts of generation. More than 80 percent of that, or 1,164 units with a capacity of nearly 3 GW, were with MidAmerican Energy Company.