Energy Department supports Iowa State studies of concrete for taller wind turbine towers

Iowa State's Sri Sritharan thinks concrete technology can build taller and better wind turbine towers. Larger image. Photo by Bob Elbert.

AMES, Iowa – The U.S. Department of Energy has awarded Iowa State engineers $1 million to study how high-strength concrete can be used to build taller wind turbine towers.

“I think this will revolutionize wind energy,” said Sri Sritharan, Iowa State University’s Wilson Engineering Professor in Civil, Construction and Environmental Engineering and leader of the College of Engineering’s Wind Energy Initiative. “We won’t need to transport these big tubular towers on the highways and we’ll harvest energy where it’s needed.”

Sritharan said concrete towers have several advantages over today’s 80-meter steel towers:    

• They can reach beyond 80 meters, providing energy companies with access to the faster and steadier winds at 100 meters and higher.
• They increase the amount of time turbines are productive.
• They allow wind energy harvesting in regions of the country where favorable winds are only above 100 meters and demand for energy is high.
• And, they contribute to the reduction of wind energy costs by reducing the production and transportation costs of towers.  

The energy department project will build on Sritharan’s earlier work to develop and test concrete wind turbine towers. The tower technology, called Hexcrete, uses precast and easily transportable components to build hexagon-shaped towers from concrete panels connected to concrete columns.

Sritharan and former graduate student Grant Schmitz tested full-size tower segments and connections last year. The tests found the concrete technology could be designed to handle the load expected for taller towers at extreme conditions.

And so Sritharan thinks concrete towers can do a lot for the wind energy industry and for the American economy: “If used for the entire height,” he wrote in a project summary, “the Hexcrete concept will eliminate transportation challenges and engage a well-established U.S.-based precast concrete industry in the wind tower business, thereby greatly reducing reliance on foreign steel and increasing the job market in the U.S.”

In addition to the energy department’s 18-month grant, the wind tower project will be supported by a grant of $83,500 from the Iowa Energy Center and $22,500 of in-kind contributions from Lafarge North America Inc. of Calgary, Alberta, Canada. The project’s industry partners also include the Siemens Corporation’s Corporate Technology center in Princeton, N.J.; Coreslab Structures (OMAHA) Inc. of Bellevue, Neb.; and BergerABAM of Federal Way, Wash.