An eastern Nebraska concrete company is working with researchers at Iowa State University to develop a new type of taller tower for wind turbines.
Instead of being constructed in steel, these towers use precast six-sided concrete panels, made at Coreslab Structures in Bellevue.
Grant Schmitz, an I-S-U engineering grad student, says one plus is eliminating the need to move those giant steel columns by truck.
“The main advantage with the precast concrete tower design that we came up with was the transportation benefits,” Schmitz says. “We can break this into smaller pieces that we can transport using standard flatbed shipping without the need for any permitting.”
The steel towers now come from all over the U-S, even from out of the country, while Schmitz says the concrete towers could be built locally.
“I think you can basically find a pre-cast plant within 200 miles of anywhere in the U-S. So, any pre-cast plant could essentially create these components and be much closer to the wind farm sites than some of these steel manufacturers,” Schmitz says.
The current steel towers usually stretch to about 260 feet, but the concrete structures could climb to 320 feet for a better chance of catching the prairie winds.
It translates to a 15-percent minimum increase in energy production. Schmitz and the others in the civil, construction and environmental engineering departments have been testing the strength of the concrete panels. He believes the concrete would last longer than the steel towers.
“Right now, steel towers are currently limited by the fatigue life of the tower to about 20 years, and concrete generally has a better fatigue performance,” Schmitz says. “Our hope and our thoughts are the fatigue life would be longer than what you’d get out of a steel tower, so instead of a 20-year service life, we could be looking at 25 or 30-year service life.”
Schmitz says more study is needed to compare the cost of putting up concrete towers versus steel. He says if all the additional testing pans out, they could be ready to start using the concrete towers in a few years.