MidAmerican using concrete tower

With an eye toward capturing more wind at higher altitudes, MidAmerican Energy is installing a concrete tower at its new wind farm in Adams County.

The concrete tower will provide support for the tallest land-based wind turbine ever built in the country, according to Mike Gehringer, vice president, renewable energy for MidAmerican Energy.

'Advancements in turbine design and construction techniques are opening up new opportunities for development of renewable resources,” Gehringer said in a news release.

Des Moines-based MidAmerican Energy has contracted with Siemens for the supply and construction of the new concrete tower.

Gehringer said MidAmerican and Siemens view the tower as a prototype that could serve as the model for other concrete turbine towers at future wind farms. The companies also expect it to open up low-to-medium wind resource areas of Iowa for future wind development.

'The process of building a concrete tower is quite different from the process we use to construct turbines with steel towers,” Gehringer said. 'Instead of building the tower sections in a factory and transporting them to the site to be fitted together, crews pour the concrete in segments and manufacture the tower onsite.”

The 2.3-megawatt concrete tower wind turbine at the Adams County wind farm will measure 377 feet from ground to the hub where the blades are attached, compared with 263 feet for most of the turbines in use at other MidAmerican Energy wind farms.

With blades extended, the turbine will reach a height of 554 feet, making it about as tall as the Washington Monument.

Michael McManus, director of business development and strategy for Siemens Americas Onshore Wind, said it will be the first concrete tower project for Siemens in North America.

'We're proud to say that this patented Siemens tower technology was conceived, designed, engineered, and constructed entirely in the United States,” McManus said in a news release.

Siemens will supply the wind turbine blades for the entire Adams County project from its blade factory in Fort Madison.

The concrete tower wind turbine is one of 64 wind turbines planned for the wind farm. All wind turbines for the 154-megawatt project are scheduled to be erected by the end of this year.