Marcio Loos and others at Case Western Reserve University in Cleveland, have built what they say is the world's first polyurethane blade reinforced with carbon nanotubes -- making it lighter and eight times stronger than blades made with current materials such as epoxy resin, fiberglass, carbon fiber and aluminum -- a university release reported Tuesday.
To meet the expansion expected in the market for wind energy, turbines need to be bigger, but just building larger blades isn't a smart answer, researchers say. The heavier the blades, the more wind is needed to turn the rotor, and the more the blades flex in the wind, the more they lose the optimal shape for catching moving air.
Lighter, stiffer blades would enable maximum energy and production, Loos says.
Carbon nanotubes are lighter per unit of volume than carbon fiber and aluminum, and have more than five times the tensile strength of carbon fiber and more than 60 times that of aluminum.
"The idea behind all this is the need to develop stronger and lighter materials which will enable manufacturing of blades for larger rotors," Loos said.