New wind turbine drivetrain without a giant bearing finishes first test, moves toward 22 and 30 megawatt designs

A wind turbine drivetrain without a giant bearing

A European Union funded project called LIGHTWIND has finished the first physical test of a wind turbine drivetrain that removes the large main bearing found in most wind turbines. The drivetrain, called OptiGen, replaces that bearing with a wheel and rail system placed near the generator air gap, the gap between its spinning and stationary parts. Optimized Generators SL, the Barcelona based company coordinating the project, finished a first test round and is starting a second to refine the design. This is a research milestone, not a finished product, a wind turbine drivetrain without a giant bearing tested so far at 15 megawatts, with a 22 megawatt version planned next and a 30 megawatt version being assessed for scalability.

Testing targets a proven technology milestone

Testing used a custom rig plus a hexapod, a device that moves a test object in many directions, called Beat 1.1 and built by IDOM, at the Fraunhofer IWES facility in Hamburg, Germany, separate from Barcelona where Optimized Generators SL is based. The phase targets Technology Readiness Level 4, an engineering scale measuring how proven a technology is, with a higher number meaning closer to commercial use. Testing so far uses the IEA Wind 15 megawatt reference turbine, a published industry standard used for comparison, not a turbine already for sale. The next step scales that reference to 22 megawatts, using a second standard, the IEA Wind Task 55 reference, before checking whether the same approach can reach 30 megawatts.

Weight is the reason drivetrain design matters offshore

A drivetrain sits atop a turbine tower and turns the motion of the rotor into electricity, well over 100 meters above the water on a large offshore turbine. The IEA Wind 15 megawatt reference turbine used for comparison carries a rotor and nacelle, the housing that holds the drivetrain at the top of the tower, weighing around 1,017 tonnes, a general industry figure, not a measurement of a turbine built with OptiGen inside it. Weight placed that high bends the tower and foundation below it, worse on a floating platform, where extra weight can force a larger platform, stronger mooring lines or more ballast, all adding cost. Material published directly by the project states that final performance and weight reduction figures for OptiGen are not yet available, a detail visible only by reading the pages the project publishes, not a shorter summary of them.

Nearly all the funding comes from the European Union

LIGHTWIND runs from October 2024 to September 2027, with a total project cost of 2,994,871.98 euros, of which 2,994,871.69 euros comes from the European Union, so the European Union funds nearly the whole project. Nine partner organizations across 7 countries, Spain, the Netherlands, Germany, Poland, Denmark, Greece and Norway, share that funding, from 33,564.96 euros for the smallest share, held by Marine Resources Advisory Team AS in Norway, to 806,678 euros for the largest, held by Fraunhofer Gesellschaft in Germany, per the European Commission project record. In January 2026, 9 European governments and the offshore wind industry signed a pact in Hamburg targeting a 30% cut in offshore wind electricity costs by 2040, and material published by the project states LIGHTWIND has no validated results yet against that target.