In two separate developments regarding direct drives, two companies say they are aiming at 6-MW ratings for offshore designs. In one, France-based turbine manufacturer Alstom and EDF Energies Nouvelles agreed to bid jointly on 3 GW of offshore construction. The consortium says it hopes to win tenders to build a third of the 3 GW with Alstom’s 6-MW turbines. The company also says a partnership with French generator manufacturer Converteam will bring the company’s direct drive, permanent-magnet generator to Alstom’s under-development offshore wind turbine.
Under the terms of the alliance, Converteam will supply its Advanced High Density direct-drive PMG. “The generator will have the largest torque of any PMG built to date,” says Converteam CEO Pierre Bastid. “This project lets us take a big step in commercializing large direct-drive wind generators.” The first two units are scheduled for installation off the coast of Belgium during the winter of 2011-2012, in collaboration with developers Belwind as part of a roughly 40-MW demonstrator project.
Alstom’s turbine, which boasts a 150-m rotor, is under development in Barcelona, Spain. It will be “simple, reliable, and effective,” says company VP of Offshore Frédéric Hendrick. Engineers will begin two prototypes in July, which will be tested on land in 2011. They are scheduled to launch next year at Belgium’s Belwind project. “We are consulting on the ports’ capacity to accommodate an industrial cluster,” says Hendrick. The factory would also produce turbines for Germany and Belgium. The first production run of a dozen machines is planned for mid-2013, with full production slated for 2014.
At the end of March, GE announced it had entered into a roughly $3.2 billion agreement to acquire some 90% of the equity in Converteam from a controlling shareholder group. GE’s announcement followed a similar move from American Superconductor Corp., which has agreed to acquire Finland-based The Switch Engineering Oy, a $265 million acquisition. AMSC said it expects The Switch’s background in advanced synchronous generators to help commercialize superconductor generators for its direct drive 10 MW SeaTitan turbine.
In a second development, Siemens has started testing its first 6-MW SWT-6.0-120 direct-drive wind turbine offshore in Høvsøre, Denmark. As a direct drive, it does not use a large gearbox, but rather directly turns the generator at the same speed as the rotor. The unit is expected to require less maintenance than a conventional turbine with a gearbox, making the direct-drive unit a good pick for offshore work. Although direct drive comes with a higher capital costs, the added reliability is expected to offset the extra cost.
This is the third direct-drive turbine Siemens has developed. The company says it has a power-to-weight ratio comparable to that of 2 and 3-MW models. This improvement means weight will affect installation less negatively than other 6-MW turbines. The high weight of wind turbines affects other costs as well because it makes transportation and installation difficult. The combined weight of the SWT-6.0-120′s nacelle and blades is 350 tons. Serial production begins in 2014.
Filed Under: Gearboxes, News, Offshore wind