Bigger is better when it comes to wind turbines. But reducing the cost of wind power could require designers to rethink an essential element of existing turbine technology: the generator. The electrical generator is the part of a wind turbine that converts the mechanical energy generated by the blades into electricity. Today, most wind turbine generators are connected to a gearbox, which steps up the speed of the spinning turbine blades, so that the torque requirements for the generator can be lower. While this technology is extremely effective in the field today, the larger wind turbines become, the heavier and more costly the generators must become. The result would be increased power – but at a higher cost.
GE Global Research, the technology development arm of General Electric, is trying to address this Achilles’ heel of wind turbine technology. The firm has announced that it is partnering with the Oak Ridge National Laboratory to develop a generator to support large-scale wind turbines in the 10-15-megawatt (MW) range. Work has begun on the first phase of the two-year, $3 million project funded by the U.S. Department of Energy.
The goal is to reduce the size and weight of the generator, while reducing blade speed and increasing torque. GE’s approach uses superconducting technology to increase the efficiency of the generator and eliminate the gearbox. The machine will incorporate a novel architecture and cryogenic cooling technology to increase reliability. Researchers hope that the increased power, combined with higher efficiency, will achieve greater economies of scale, reducing the cost of wind generation.
Phase I of the project will focus on developing a conceptual design and evaluating the economic, environmental and commercial factors associated with it. Phase II will explore the potential commercialization of the technology.