Low Windspeed Wind Turbine

Well over 50 % of US land area constitutes low wind-speed sites, yet wind turbines are either not effective or only marginally effective in such low winds. To extract significantly more energy from such DOE Class 1 or Class 2 winds requires substantially increasing turbine blade rotor diameter (wind power is proportional to the square of the blade diameter). However, due to limitations on turbine blade tip speed, this cannot be done without significantly decreasing blade rotor rpm (blade tip speed is directly proportional to rotor rpm), which in turn, due to limitations on generator output at low rpm, is notoriously costly to do. This makes genuinely low wind-speed, wind-electric power conversion commercially impractical. A recently introduced generator design addresses this issue. However, further work to more fully characterize and further develop this design is required. As a result, R&D work is being proposed that will include generator prototype construction, and extensive testing and modeling.