Siemens will deliver six ST-3.0-101 direct-drive turbines for an onshore project at Akita Port. The German manufacturer will also maintain the turbines, which are expected to be installed and operating by mid-2014.
The SWT 3.0 was launched in 2010 and is the company's first direct-drive machine. It won the best turbine 3MW-3.5MW category in Windpower Monthly's Product of the Year feature.
Last month, Eurus Energy awarded a 16.7MW deal to French manufacturer Alstom, for another project in western Japan.
This is not the first deal between the two companies. In 2006, Siemens supplied 15. 1.3MW turbines for a 19.5MW wind farm in the village of Sanagochi on Shikoku, the smallest of Japan's four main islands.
Japan is expected to increase its wind power capacity in the coming years as it focuses on renewable energy in the aftermath of the Fukushima nuclear disaster.
The government recently confirmed that the recently introduced onshore wind tariff of JPY 23.1/kWh ($0.28/kWh) will remain unchanged, while the solar tariffs will decline. The offshore tariff is as yet undecided.