Successful 2006 Large Wind Turbine Projects

Clipper Windpower

Northern Power Systems (NPS) produced an award-winning electronics package that can be scaled for use in a wide range of wind turbines, from small to multimegawatt systems. According to NPS, the new converter improves wind turbine reliability, energy capture, and grid performance. The project team was chosen by the American Wind Energy Association for its 2006 Technical Achievement Award. Tests completed in 2006 on both the converter and a 1.5-MW direct-drive , also developed with program support, demonstrated high- power output.

Knight & Carver is developing a 27.5-m (90-ft) replacement blade for a 750-kW turbine. The “STAR” (which stands for sweep twist adaptive rotor) blade is the first of its kind ever built. Its most distinctive characteristic is a gently curved tip, which prompts the blade to respond to high winds such that adverse loads are attenuated. This allows the blade length to be extended with no weight penalty and augments energy capture in low-wind-speed resource areas.

Global Energy Concepts (GEC) worked with program researchers to fabricate a 1.5-MW, single-stage drivetrain with a planetary gearbox and a medium-speed, permanent-magnet generator. The simple gearbox and moderate-sized generator show potential for reducing tower-head weight and drivetrain . The company completed initial testing of this drivetrain at NREL's 2.5-MW dynamometer test facility. The generator is currently being upgraded, and a second phase of testing is planned for 2007.

Genesis Corporation is testing a new tooth form for gearboxes that promises major improvements in power density while reducing the costs of these devices. The company completed the first round of testing with positive results and is now working to refine its design through further targeted testing.