GE makes a world of products using different materials and processes. But the same research innovations that make an airplane engine lighter and more fuel efficient can make a windmill blade longer and lighter – the technologies are connected, sometimes it just takes some ingenuity to make the leap.
That’s why the idea of using magnet technology from GE MRI machines to create the next generation of wind turbines is so exciting. The project, which is underway at GE Global Research as part of a two-year, $3 million project from the U.S. Department of Energy, aims to create turbines with almost twice the capacity as the largest ones today. It’s a marriage of almost 30 years of research into superconducting magnets for health care imaging with green energy technology that is making carbon-free megawatts cheaper for Americans.
Like any worthwhile project, this one started with a challenge: How do you maximize a wind turbine’s output without increasing maintenance requirements and dependence on rare earth materials?
The answer requires a reimagining of the turbine’s electrical generator, which converts the energy of the swooshing blades into electricity. In most turbines, the generators are connected to gearboxes that, just like a bike, allow the turbine to adjust to the wind and generate the right amount of torque.
The setup works well for 2.5-megawatt (MW) turbines but, as the plants push into the 10-15 MW range, the gearboxes become heavier and require maintenance, two factors that make energy more expensive. GE’s innovation is to use superconducting magnets similar to the ones in MRI machines to eliminate the gearbox altogether and improve the generator. This approach reduces the requirement for heavy iron in the generator and the need for rare earths in superconducting magnets. The machine will use cryogenic cooling technologies that bring temperatures down close to absolute zero.
The challenges of putting this technology in wind turbines that could go miles offshore are bracing, said Ruben Fair, a GE technologist who has worked for 17 years on superconducting and cryogenic magnet systems. “Since offshore wind farms are really only accessible once a year, weather permitting, such machines have to be ultra-reliable,” Fair said.
The first phase of the project involves developing and evaluating a design. The second phase will evaluate the project’s commercial viability.
Turbines that generate more electricity can effectively squeeze more energy out of a smaller wind farm and reduce the cost of energy. They also provide a great case for how innovation in fields as diverse as energy and health care can learn from each other.