High-Efficiency Turbine Generator for Instream Electric Power Production

Concerns over global warming due to carbon emissions have spurred an interest in such renewable energy alternatives as hydroelectric, wind, solar, geothermal, and biomass. Of all of these, hydroelectric power offers perhaps the greatest potential for supplying a significant portion of our nation's energy needs. To realize this potential, however, this technology needs to expand beyond traditional dam based installations (for which there are relatively few suitable remaining sites) into the vast number of open flow installations potentially available in rivers, canals, tidal streams and open ocean sites. To help promote this expansion, this project will focus on the development of an advanced, vertical axis, hydrokinetic power generator that is significantly more efficient, lighter, smaller, and lower energy cost than current commercial products. Two key features of this design are (1) an active blade control system that provides independent control of blade pitch and (2) a low-profile, low-speed, high-torque electric generator suitable for direct coupling to the turbine (no gearbox). Both systems will use a unique, disk-shape, high performance electromechanical structure that is potentially low cost, compact, light-weight, and very efficient. If successful, this technology will provide many benefits, including high turbine efficiency, high starting torque, less vibration, speed control independent of generator load, and a mechanism to help clear debris caught in the blades. The Phase I effort will develop preliminary designs of this system for several turbine sizes. Performance, size, weight and energy cost attributes will be evaluated, and the technology’s feasibility will be assessed based on comparisons with other hydrokinetic generator products. Assuming feasibility is confirmed, Phase II will be used to construct and test a working prototype system and validate performance expectations. Commercialization of the technology will be pursued following successful validation. Key Words: hydroelectric, hydrokinetic, turbine, actuator, generator