Halfway Through Bison I Wind Farm, Minnesota Power Upgrades Technology by Switching to Direct-Drive Wind Turbines

As the first half of its Bison I Wind Power Project in North Dakota nears completion, Minnesota Power is shifting into 2011’s second phase by upgrading to even more efficient, new direct drive wind turbines that will deliver more wind energy to Minnesota Power customers.

For the second phase of its first wind energy project in North Dakota, the Duluth-based division of ALLETE, Inc. (NYSE: ALE) will install 15 new 3-Megawatt (MW) wind turbines manufactured by Siemens instead of the 17 wind turbines of 2.3 Megawatts originally planned. The new turbine arrangement is expected to generate an additional 10,000 Megawatt hours of annual energy.

The new SWT-3.0-101 direct drive wind turbines were described as “game-changing” by the CEO of Siemens’ wind power business unit in a news release announcing Minnesota Power’s order for the new equipment. Siemens’ direct drive wind turbine features a permanent magnet generator but no gearbox. With the number of parts in the wind turbine reduced by half, the direct drive technology has the potential to reduce maintenance time, resulting in higher wind turbine availability.

“We’re very excited to apply this leading-edge technology in North Dakota, where the renewable energy potential of wind is unmatched,” said Eric Norberg, Minnesota Power Senior Vice President of Strategy and Planning. “Our customers will benefit from the additional energy production and the likelihood of improved efficiency for many years.” The project is part of the Company’s overall effort to meet Minnesota’s renewable energy mandate to deliver 25 percent of its energy from renewable sources.

Minnesota Power, Siemens and other contractors have been working since the spring of this year on the first phase of Bison I wind farm, located in west-central North Dakota near the town of New Salem.

Major components began arriving on the worksite in September, and the last of the phase one turbine structures was erected in mid-October. All 16 wind turbines in Bison I’s first phase are now operational. Renewable energy generated at the Bison wind farm will be delivered to Minnesota Power’s customers in northeastern Minnesota, over a 465-mile direct current transmission line it purchased on Dec. 31, 2009.

“Bison positions us at the forefront of renewable energy production as our nation transforms its energy landscape,” said ALLETE President and CEO Alan R. Hodnik. “Embracing new technology is part of that evolution and reflects our commitment to providing greater value to our customers and shareholders.”

Minnesota Power provides retail electric service within a 26,000-square-mile area in northeastern Minnesota to 144,000 customers and wholesale electric service to 16 municipalities.