The US National Renewable Energy Laboratory (NREL) after collaboration with global researchers has released a reference offshore wind turbine design with a 15MW nameplate capacity for both fixed-bottom and floating applications.

The reference wind turbine (RWT) – a complete open-source turbine system with supporting models for simulation and design – makes it possible to evaluate the performance and cost of modifications before prototype development, said the partners.

The open-source model is named IEA 15MW after the International Energy Agency, which helped to coordinate the research collaboration. It is available on GitHub.

The RWT can accommodate multiple software tools and will provide industry, researchers and academics with a public-domain tool for designing next-generation offshore wind turbines, according to NREL researcher Evan Gaertner, who led the design effort.

He noted configurations of the IEA 15MW go beyond the capabilities of the 10-12MW offshore turbines already in development by industry, but are similar enough to serve as a baseline for 15-20MW next-generation designs.

“The IEA 15MW will serve as a valuable development resource for the foreseeable future,” he said, claiming it will help support cutting-edge research for years to come.

Several projects and project proposals are starting to use the reference turbine, even in its prerelease state. It’s already being used to study lightweight generators and floating support structure design, and to conduct wind turbine software tool comparisons, said Gaertner.

NREL worked in collaboration with the Technological University of Denmark [DTU] and the University of Maine [UMaine]. NREL designed the rotor, generator, drivetrain, nacelle, tower, monopile, and controller.

DTU reviewed the design and suggested improvements, performing loads analysis and developing public domain models for their simulation toolsets. UMaine also designed the semisubmersible loading substructure.

The most powerful wind turbine currently nearing commercial deployment is the 12MW GE Haliade-X, but several OEMs are known to be working on projects to push that up further. Recharge revealed how Siemens Gamesa recently protected technology associated with its hotly-anticipated ‘1X’ offshore wind turbine concept – widely expected to be one of a fleet of next-generation machines in the nameplate range of 14-16MW.

While the US has only a single 30MW offshore wind farm in commercial operation, its development pipeline exceeded 26GW last December, according to the federal Bureau of Ocean Energy Management (BOEM).

Out of this pipeline, developers anticipate 14 projects totaling 9.1GW to be operational by 2026, assuming BOEM adheres to present permitting timelines.

The IEA 15MW was partially funded by the US Department of Energy's Office of Energy Efficiency and Renewable Energy’s Wind Energy Technologies Office.