The US Department of Energy has selected four projects for funding led by GE, ABB, WEG Energy and American Superconductor Corporation that aim to develop next-generation turbine drivetrain technologies to boost individual output to up to 15MW.
GE is developing a high-efficiency ultra-light low temperature superconducting (LTS) generator, using innovations developed by the company’s magnetic resonance imaging business.
The generator will be tailored for offshore wind and scalable beyond 12MW.
DoE said the advantage of LTS generators is the availability of low-cost LTS wire in lengths needed to wind the generator without splices.
However, the challenge with LTS is the need to cool the windings to about four degrees kelvin, which usually requires the use of liquid helium, it added.
ABB is working on a lightweight double stator generator that uses an advanced magnet cooling system suitable for both geared and direct drive machines, scalable up to 15MW, Doe said.
WEG Energy Corporation is developing a high-efficiency permanent magnet direct drive lightweight generator to integrate into its existing platform.
American Superconductor Corporation is working on a turbine that incorporates high-temperature superconductor (HTS) materials to replace permanent magnets in the generator rotor.
This has the potential to reduce the size and weight by 50%, DoE said.
“The advantage of an HTS design is the higher operating temperature of the generator windings, which significantly reduces the challenges associated with maintaining supercritical temperatures in the generator,” it said.
However, the winding material is expensive, and it comes in relatively short lengths, necessitating many splices, DoE added.
The $8m projects will each receive up to $400,000 from the DoE.
After a design and analysis phase, DOE will select one project to receive up to $6.4m to build and test a scaled prototype on a wind turbine.