The U.S. Department of Energy (DOE) has selected four projects totaling up to $8 million to develop next-generation wind turbine drivetrain technologies for onshore and offshore applications.
According to the DOE, these projects will develop more efficient, smaller and lighter-weight generators in an effort to lower costs and make wind power more affordable.
Each of the selected projects will receive up to $400,000 to design a wind turbine generator that can be scaled up to at least 10 MW, capitalizing on the trend of larger, more powerful turbines, especially for offshore applications.
Two projects are developing direct-drive permanent-magnet designs:
- ABB Inc. of Raleigh, N.C., will develop a lightweight, double-stator generator that uses an advanced magnet cooling system suitable for both geared and direct-drive machines, scalable up to 15 MW.
- WEG Energy Corp. of Duluth, Ga., will develop a high-efficiency, permanent-magnet direct-drive lightweight generator to integrate into its existing platform.
Two projects will develop superconducting generators, which make a much stronger magnetic field using superconducting windings:
- American Superconductor Corp. of Ayer, Mass., will develop a high-efficiency, lightweight wind turbine generator that incorporates high-temperature superconductor (HTS) materials to replace permanent magnets in the generator rotor, potentially reducing size and weight by 50%. The advantage of an HTS design is the higher operating temperature of the generator windings, reducing challenges associated with maintaining supercritical temperatures in the generator. The challenge with HTS machines is that the winding material is much more expensive, and it comes in relatively short lengths, necessitating many splices.
- GE Research of Niskayuna, N.Y., will develop a high-efficiency, ultra-light, low-temperature superconducting (LTS) generator, leveraging technology from GE’s magnetic resonance imaging business. The generator will be tailored for offshore wind and scalable beyond 12 MW. The advantage of LTS generators is the availability of low-cost LTS wire in lengths needed to wind the generator without splices. The challenge with LTS designs is the need to cool the windings to about 4 degrees Kelvin, which typically requires the use of liquid helium.
If successful, these four research projects could result in designs up to 50% smaller and lighter and reduce the cost of wind generation by 10%-25%, says the DOE.
After the projects complete a design and analysis phase, the DOE will select one project to receive up to $6.4 million to build and test a scaled prototype of the generator on a wind turbine.