GE Applying MRI Magnet Technology to Scale-Up to 15MW Wind Turbines

August 30, 2011 by Jeff Shepard

GE Global Research, the technology development arm of the General Electric Company, announced that it has begun work on the first phase of a 2-year, $3 million project from the U.S. Department of Energy to develop a next generation wind turbine generator that could support large-scale wind applications in the 10-15MW range. This project is one of many in GE’s wind research portfolio focused on scaling up wind power in the most economically feasible way.

"With the industry’s desire for higher megawatt machines to maximize clean wind power opportunities in the U.S. and around the globe, new technologies will be needed to support larger scale wind platforms," said Keith Longtin, Wind Technology Leader, GE Global Research. "The key challenge will be delivering solutions that achieve the right scale and cost. Applying more than 30+ years of experience with superconducting magnets for MRI systems in healthcare, we’re developing an innovative new generator technology that will deliver more power while at the same time helping to reduce the cost of wind power."

"For MRI systems, we’re applying superconducting magnets to make lower cost systems with higher image quality," Longtin said. "For wind turbines, we want to apply them to generate more wind power at a lower cost of electricity. The applications are different, but the basic technology is the same."

An electrical generator is the critical part of a wind turbine that converts the mechanical energy generated by the blades into usable electrical power. How effective your generator is directly impacts how much wind you can convert into electric power.

Longtin explained that the innovative application of superconducting technology could enable significant improvements to the generator and make the elimination of the gearbox more economical. The keys are reducing the size and weight of the generator, while reducing speed and increasing torque. Utilizing superconducting technology reduces weight by virtue of the high magnetic fields that can be created by the superconducting field winding and the fact that the heavy iron in the superconducting generator can be reduced.

GE’s superconducting machine design will employ a novel architecture and proven cryogenic cooling technology, resulting in an improvement in reliability of the complete machine. GE’s proposed superconducting machine aims to have twice the torque density of competing technologies and will additionally reduce the dependence on the rare earth materials prevalent in all permanent magnet machines for wind. The larger power levels of these machines, coupled with their improved energy conversion efficiency leads to more favorable economies of scale (e.g., fewer towers for a given wind-farm output) that will help reduce the cost of energy produced by wind turbines.

The generator project will have two phases. Phase I 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. The Oak Ridge National Lab (ORNL) will be a key partner with GE on the generator project, helping GE to investigate and mitigate high-risk technology challenges associated with the project.