First-of-its-kind research at Iowa State is leading to the development of taller towers capable of harvesting more wind energy and expanding wind energy to places where it is currently unfeasible.
“The expectation is that we will be able to generate more energy close to where the demand is high,” said Sri Sritharan, leader of the Iowa State University College of Engineering’s Wind Energy Initiative. “What we’re focusing on is a new concept that will revolutionize the wind energy market. Ideas others have put forward tend to be more incremental in nature.”
Sritharan has assembled a team of researchers who are developing wind towers made of concrete that can be built up to 40 meters taller than existing steel turbine towers. The initiative is the only wind tower research project that is funded by the U.S. Department of Energy.
“If you go taller, there are multiple advantages,” Sritharan said. “If the tower height goes up, the velocity of the wind goes up. If the velocity of the wind goes up, power generation increases.” He added initial studies have shown the taller towers could allow their turbines to generate at least 10 to 12 percent more electricity.
The Iowa State University concept involves stacking hexagonal sections of high-strength precast concrete to a height up to 120 meters. By using concrete, developers can rely upon local firms to transport and assemble the sections, rather than using imported steel. It also solves critical transportation issues. A 120-meter steel tower would require a base with an 18-foot diameter, which is four feet taller than the standard clearance for Interstate highway overpasses.
The greatest advantage to the taller concrete towers, Sritharan said, is that they will open up areas of the nation, like the air conditioning-dependent southwestern United States, to cost effective wind energy generation. Currently, there are insufficient winds in the Southwest to generate low-cost electricity from 80-meter towers.