Composite resins might take wind turbines towers to new heights

When it comes to generating wind power, it’s simple: Taller towers are key to harvesting more energy.

Problem is, steel turbine towers can only go so tall. Build one much higher than the North American average of 265 feet and not only is it not strong enough to support the weight of the turbine – which can be as much as 100 tons – but it’s also in danger of buckling under the stress of the rotating machinery. Add to that the fact that, in their present configurations, steel monopoles are pre-fabricated in sections as large as 14 feet in diameter and 70 feet long, making it difficult to ship them to the typically hilly and remote locales of current wind farm sites, and you’ve got some serious hurdles to the growth of wind power.

Scientists at the University of Dayton Research Institute (UDRI) believe they’ve hit on a way to clear those hurdles, by using fiberglass and resin composites to build turbine towers up to almost 400 feet in height.

According to Brian Rice, division head for multi-scale composites and polymers at UDRI, the fiberglass and resin composites could be used to fabricate tower sections on-site at the wind farm using raw materials delivered to the site. “On-site fabrication eliminates the transportation problems and makes more sites accessible to wind power development,” he said. Such a dramatic increase in tower height necessitates an increase in tower diameter, too, but Rice is confident a new design concept can solve that problem.

In addition, he added, the corrosion-resistant properties of composites would be far better suited than steel for offshore wind farms, which are just starting to be developed in U.S. waters.

A project team under Rice’s direction has been working on the idea for the past two years, during which time materials have been tested and coupon samples analyzed. In addition to UDRI and lead partner Ershigs Inc., the team reads like a who’s who of Ohio industry research: Edison Materials Technology Center in Dayton, WebCore Technologies in Miamisburg, Owens Corning in Columbus, and Ashland Performance Materials in Dublin.

Further boosts came earlier this year, when UDRI received US$270,000 in state funding for the project and a feasibility study was put together shortly after. The next step is to prepare for product demonstration, which includes the goal of completing and testing a full-scale 100 meter composite tower, which Rice said will be one of the largest composite structures ever built.