The tests are over, and the Bent Tree Wind Farm is on.

On Monday, Wisconsin Power & Light announced the wind farm has begun commercial operation. Coincidentally, Freeborn County was in a wind chill advisory.

“Today, we’re making some power. Today is not a bad day for the first commercial day,” said Greg Kaelberer, site manager.

Bent Tree has 122 turbines and is capable of producing up to 201 megawatts of energy, enough to power 50,000 homes. It is Wisconsin Power & Light’s second owned and operated wind farm. The first is Cedar Ridge Wind Farm, a 68-megawatt wind farm in Fond du Lac County in Wisconsin. It became operational in December 2008.

Madison, Wis.-based Wisconsin Power & Light is a subsidiary of Alliant Energy.

“Alliant Energy is committed to providing our customers with balanced energy solutions that are environmentally responsible, reliable and cost-effective,” said WP&L President John Larsen.

The two wind farms were built to meet Wisconsin mandates for renewable energy. Kaelberer said the mandates are met by using energy from the two wind farms and by purchasing energy from renewable sources.

“I feel fairly excited about the project coming to this point,” Kaelberer said, noting the wind farm will reduce the need to burn as much fossil fuel.

Construction started on the Bent Tree Wind Farm in April 2010, with a goal of being done in March 2011. Construction wrapped up on Jan. 9. It is considered the first phase of the Bent Tree Wind Farm. The wind farm is licensed for up to 400 megawatts, and WP&L has lease options in place should more wind turbines need to be built.

Kaelberer said building a second phase would depend on the regulatory situation in Wisconsin, Iowa or Minnesota. If legislatures mandate an increase in standards for energy from renewable sources, then construction could happen.

Right now, there are no immediate plans for more towers, he said.

This spring and summer, people can expect Bent Tree crews to move dirt around the towers and repair wind farm roads and Freeborn County roads, Kaelberer said. Much of the road work, mainly in the north half of the site, stopped once the ground froze.

People living near the wind farm have seen the turbines operate. Kaelberer said before Monday the wind farm had been producing test power. He said the energy produced could not be counted as commercial until all the wind turbines were constructed and tested.

“We now can pass the baton from construction to operations,” Kaelberer said.

The operations building in Hartland has five Alliant Energy employees and about 15 employees from turbine manufacturer Vestas, he said. The Vestas employees monitor and make repairs on the V82 turbines for three years before handing that role over to Alliant Energy. There are about other five contracted workers who do jobs such as janitorial, snow removal or road repair.

So while the construction phase brought as many as 300 workers last summer into the Harland-Manchester area, the operations phase leaves about 25.

Ted Francois, the project developer, said he is glad to reach this point. He said people will see the turbines functioning when the wind is strong enough to generate electricity unless either they are being repaired or the Midwest Independent Transmission System Operator, which oversees the Midwest power transmission system, asks Bent Tree to curtail power generation temporarily for various reasons.