GE says its experience with superconducting equipment from its healthcare MRIs is applicable to generators for wind turbines. High torque at low rotational speeds may let wind turbines product up to 15 MW and without a gearbox.
GE Global Research, the technology development arm of GE, says 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 applications in the 10 to 15-MW range. “With the industry’s quest 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. “Applying more than 30 years of experience with superconducting magnets for MRI systems in healthcare, we’re developing a generator technology that will deliver more power while at the same time reducing the cost of wind power.”
“MRI machines use 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.”
Today, most conventional wind turbines use a gearbox to increase slow rotor speeds to a higher rpm needed by induction generators. While such drivetrains are effective in today’s wind turbines, they become expensive as they scale to larger wind platforms because of their additional weight and maintenance needs. It may be possible to get additional power from a larger drivetrain, but it comes with an increase in the cost of electricity.
Longtin says the application of superconducting technology could enable significant improvements to the generator and eliminate the gearbox. The keys are in reducing the size and weight of the generator, while dealing with lower shaft speeds and high torque. Superconducting technology allows a lighter weight generator that uses high magnetic fields made possible by superconducting materials and the fact that such a generator needs less steel than a conventional generator.
GE says its superconducting machine will use an architecture and proven cryogenic cooling to improve the reliability of the complete machine. GE’s proposed superconducting machine aims to have twice the torque density of competing technologies and will further reduce dependence on rare-earth materials prevalent in permanent-magnet generators that are finding favor in many modern turbines. The larger potential power levels of these machines, coupled with better 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.
In addition to the next generation wind turbine generator project, GE says its researchers are driving other key technologies that will allows the economic scale-up of wind. A few details include:
• Using lighter, more advanced composite materials for longer blades to improve wind capture without adding so much weight that it increases the cost of power
• More advanced controls, sensors, and condition monitoring algorithms to reduce operating costs, and
• Developing an array of grid integration technologies to feed larger amounts of wind-generated power into the grid. Such equipment focuses on making sure wind turbines are grid-code compliant and provide grid-friendly features to help utilities more reliably manage larger wind power loads.
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.
GE Global Research
www.GE.com/wind
Filed Under: Generators, News, Turbines
