Bison Wind ship on its way to Duluth

Bison Wind ship on its way to Duluth Friday, July 30, 2010 Minnesota Power's ship, the BBC EMS, is coming in.

When the BBC EMS steams under Duluth’s Aerial Lift Bridge next month, crowds won’t be hanging over the canal piers and lining the banks of Lake Superior to get a look at the vessel.

The EMS isn’t a tall ship and it was built only four years ago. But when it enters the Duluth harbor on August 10 or 11, ALLETE and Minnesota Power employees from here to New Salem, N.D. will be paying close attention because of the ship’s cargo.

The BBC EMS may not be tall, but it’s heavy. The cargo ship is loaded with wind turbine equipment destined for MP’s Bison Wind Energy Center currently under construction near New Salem. Now on her way across the North Atlantic, the ship left the port of Aarhus, Denmark July 23, headed for the St. Lawrence Seaway entry on the East Coast.

On board the ship are 16 nacelles and 16 rotor hubs that are integral components of the first phase of Bison. Of a total 33 wind turbines to be installed in the project by the end of 2011, 16 will be assembled and scheduled for activation by the end of this year. Each nacelle supports a rotor and encloses a wind turbine plant’s major components for electric power generation -- the gearbox, drive train and control electronics. A rotor hub fits on the front of the nacelle and contains large holes where the blades will be fitted. Each rotor and hub set weighs 144 tons.

The equipment was manufactured at a Siemens facility not far from Aarhus in Brande, Denmark. The blades for Bison will be fabricated in a Siemens facility in Fort Madison, Ia. and trucked to the construction site.

Towers for the wind turbines will be built in West Fargo, N.D. The Siemens 2.3 megawatt turbines are similar to those used in the Oliver Wind I installation near Center, N.D. constructed in 2006 by NextEra Energy. Minnesota Power buys all the energy output from Oliver I and Oliver II, an adjacent wind farm utilizing General Electric turbines.

There is still much to be done at the Bison I construction site before the nacelles are delivered there by truck in mid-September, but work is progressing smoothly according to Ron Gullicks, large projects control manager for the Bison project.

Foundations and structures for the 22-mile transmission line connecting Bison with the Square Butte Substation in Center have been installed, Gullicks said, and line is being strung across the 132 H-frame wood and steel structures. Foundations have been completed for the Bison substation and the addition to the Square Butte substation. Prefabricated and pre-wired control houses for each substation have been delivered, he said, and structural steel was being erected there earlier this week.

An operations and maintenance building that includes offices, storage and warehouse and a garage are now being finished, Gullicks said. A total of about eight miles of access roads for Bison’s phase one is “about 75 percent complete,” he said. Excavation of turbine foundations has begun, and the first concrete pours for foundations are expected soon.

To get an idea of the size of the wind tower foundations, each one requires 452 cubic yards of concrete.

Pedestals for the turbine towers contain 160 anchor bolts. Gullicks said that in keeping with the concept of renewable energy, a ground source heating system is being installed in the Bison operations and maintenance building.