Lab Helps Design a Better Turbine Blade to Produce Electricity
ALBUQUERQUE, N.M. Promising initial tests show designs and technology developed by Sandia National Laboratories could allow wind turbines to produce power in lighter breezes.
Engineers at Sandia and the National Energy Renewable Laboratory, NREL, in Golden, Colo., say a prototype turbine blade that contains carbon fiber performed better than expected in tests that simulate vibration and stress caused by prolonged exposure to wind.
"It's good news," said Tom Ashwill, a principal member of the technical staff at Sandia's Wind Energy Technology Department.
The department has been working for three years to develop new designs and technology that will enable manufacturers to produce stronger, lighter and more flexible wind turbine blades.
Blade manufacturer TPI Composites in Rhode Island has so far produced seven prototype blades, each about 30 feet long, that will undergo lab and field tests to simulate power-producing conditions.
Commercial wind turbine blades have 115-foot-long fiberglass blades mounted on towers between 210 feet and 260 feet tall. The turbines can produce 1.5 megawatts of electricity, enough for about 1,200 households.
NREL's National Wind Technology Center conducted the first tests on Sandia's CX100 design. The wing-shaped fiberglass blade is built around a 100 percent carbon fiber "spine."
Manufacturers currently build blades with fiberglass spines. Carbon fiber is stronger and lighter than fiberglass, Ashwill said.
Sandia and NREL hope their designs will enable manufacturers to produce larger blades that require less wind to turn them. When the blades turn, a shaft transmits the force to a generator, which produces electricity.
Being able to produce power in lighter winds could help reduce the price of energy. Sandia's Wind Energy Technology Department receives about $4 million annually from the U.S. Department of Energy to help develop technology to achieve that goal.
The positive test results on the CX100 tests mean "We're on the way," said NREL engineer Jim Johnson. Sandia and NREL plan to conduct similar tests on another blade prototype this summer, the TX100, which incorporates carbon fiber throughout the blade surface.
Ashwill said this innovation will allow the blade to twist in high winds, reducing strain and prolonging blade life.
Sandia plans to test both blade designs next spring at the U.S. Department of Agriculture's research station at Bushland, Texas, near Amarillo. They will be mounted on utility-size turbine towers and tested under real-life wind conditions, Ashwill said.
Earlier attempts to field test the blades at Bushland had to be abandoned because of an equipment malfunction early this year, he said.
Source: Knight Ridder/Tribune Business News