OFFSHORE WIND RESEARCH:
Gearing up for cheaper wind power
Norwegian company Angle Wind and its partners have developed a new type of eccentric gear configuration for offshore wind turbines. A marked improvement over conventional planetary gearboxes, the new solution will be able to cut the cost of wind farms substantially.
Now the project partners are preparing to test a durable eccentric gearbox in a 225 kW turbine at Norwegian energy company Lyse’s wind farm off Kvitsøy island in southwest Norway. The next step will be testing it in a 3 MW turbine.
Large share of total cost
Angle Wind tests a prototype of its eccentric gear configuration. (Photo: AWG)
Gears account for roughly 14 per cent of a wind turbine’s cost; only the tower and rotor blades cost more to construct. Extending the life of the gears provides big savings, since replacing the gears entails substantial operational and investment costs.
The new gear design has fewer moving parts and is more reliable than existing gearboxes.
“Now that we’ve successfully completed preliminary testing and refinement, we intend to finalise the testing of two of the gear prototypes within the next two years – at an advanced testing centre and through a full year’s turbine test,” says Anders Dirdal, CEO of Angle Wind. “Following that will come full-scale testing in a 3 MW turbine.”
“We plan to have the gear configuration market-ready in four years.”
Entire chain involved
Developing the gears has meant meshing the efforts of many throughout the entire chain from production to end-user, including producers of components and gears, a leading supplier of wind turbines, and a developer and operator of wind farms. The Research Council of Norway’s Large-scale Programme on Clean Energy for the Future (RENERGI) is providing funding for development and testing activities as part of the ongoing public initiative to promote new, renewable forms of energy.
“Thanks to this collaborative effort, we’ve been able to progress efficiently using clearly-defined requirements and test specifications, with top-notch expertise in superb facilities,” says Mr Dirdal.
With 40 per cent fewer moving parts than a planetary gear configuration, Angle Wind’s eccentric gear is lighter, more reliable and lasts substantially longer. Drivlinje = Drive train, Rotor = Rotor, Hovedlager = Main casing, Aksel = Axle, Generator = Generator, Girboks = Gearbox, Tårn = Tower. (Illustration: AWG)
Capacity up to 10 MW
So far the gear system has undergone four years of development, including a series of tests on gear configurations, couplings and transmission systems. Once the objective of running it in a 3 MW turbine has been fulfilled, the gear system will be refined and adapted so it can be integrated into new and existing generator technology – in turbines ranging up to 10 MW.
Angle Wind’s drive train technology development will also involve new types of bearings, overload couplings, hybrid generators, and solutions that allow the generator to be encased in the tower at ground or surface level instead of up in the nacelle. This final feature reduces the weight of the nacelle while providing far easier maintenance access.
Fewer parts, lighter weight
Angle Wind’s eccentric gear design features integrated bearings and consists of roughly 40 per cent fewer moving parts than a comparable planetary gear configuration. This makes the gearbox lighter yet sturdier, extending its life by at least 30 per cent. Its 20:1 transmission ratio is far superior to the 7:1 of planetary gears.
“Our solution is far more reliable and cost-effective than what is available now,” asserts CEO Dirdal.
Energy producers have high hopes. “We see the potential for Angle Wind’s new solutions for wind power, both on land and offshore,” confirms Mette Kristine Kanestrøm, head of business development for the major Norwegian energy supplier Lyse Produksjon.
| PROJECT FACTS |
| Project title: Innovative multi-MW eccentric gear for offshore wind turbines Project manager: Anders Dirdal Partners: Angle Wind, International Research Institute of Stavanger (IRIS), and a leading producer of wind turbines Project period: 2010–2012 Budget: NOK 19.2 million Funding from the RENERGI programme: NOK 6.5 million |
- Published:
- 01.12.2011
- Last updated:
- 02.12.2011
