Siemens on July 5 entered the competition for the largest wind turbine in the world with an upgrade of its SWT-7.0-154 model. The new SWT-8.0-154 turbine boosts power output over the earlier model through upgraded magnet technology. Other components remain largely the same over the earlier model and the smaller SWT-6.0-154 turbine, Siemens said.
The firm thus joins two others offering 8-MW wind turbines: MHI Vestas and Gamesa and Areva’s joint venture Adwen. Deciding which model is “largest” depends on how one defines the term, though. All are rated at 8 MW, but the MHI Vestas V164 has a larger rotor diameter at 164 meters (m) than the 154-m Siemens model.
Adwen’s AD-180 has the largest rotor diameter—at 180 m—of any commercially available design, but none have yet been constructed. Adwen and Danish firm LM Windpower completed the first AD-180 blade in June, each of which is just over 88 m long (Figure 1). The blades will be used for the AD-180 prototype planned to be built at a site in Germany later this year.
Meanwhile, the first two commercial V164 turbines entered operation in April at the Måde project near the port of Esbjerg, Denmark, making them the largest wind turbines currently in service.
The race for the largest model is likely to take another turn after Siemens and Gamesa merge their wind operations next year. Areva has an option to buy out Gamesa’s stake in Adwen or exit the joint venture, either selling it to a third party or selling its share to Gamesa. Those options expire in September.
Two Siemens SWT-7.0 prototypes are currently in operation (Figure 2). Siemens says the first SWT-8.0-154 prototype will be completed in early 2017.
Giant wind turbines remain mostly a European phenomenon, as the models are mainly intended for offshore use. The first offshore wind turbine project in the U.S., the Block Island Wind Farm, is under construction off Rhode Island and will employ five Alstom 6-MW Haliade 150 turbines. It’s slated for operations later this year.
—Thomas W. Overton, JD is a POWER associate editor (@thomas_overton, @POWERmagazine).