In a rare move, a state judge has recommended that a proposed southern Minnesota wind farm — Freeborn Wind — be denied an operating permit, saying the project has failed to show it can meet state noise standards.

Meanwhile, the owner of Bent Tree Wind Farm, which is also in Freeborn County, recently agreed to buy the homes of two families who have long complained about excessive noise.

The proposed Freeborn Wind project southeast of Albert Lea would exceed maximum levels of allowed noise and therefore shouldn't get a permit from the Minnesota Public Utilities Commission (PUC), Administrative Law Judge LauraSue Schlatter wrote in an opinion released earlier this week.

Schlatter also wrote that Freeborn Wind's developer, Invenergy, should be given time to submit a plan on how it would comply with Minnesota's noise laws.

Administrative law judges like Schlatter are appointed to examine contested cases before the PUC, and their rulings are nonbinding recommendations. However, they often carry significant weight with the PUC.

"The importance of this ruling is that the judge recognized noise impacts are significant and real," and that Invenergy demonstrated it couldn't follow state rules, said Carol Overland, an attorney for the Association of Freeborn County Landowners, which opposes Freeborn Wind over fears of excessive noise and other issues.

Dan Litchfield, an Invenergy senior manager, objected to Schlatter's interpretation of Minnesota's noise regulations, saying it "is impossible to meet for a wind farm. … Every other wind farm in the state has not been subject to this interpretation."

Chicago-based Invenergy, a major U.S. wind power developer, contends the Minnesota noise standard applies to wind turbine sounds alone. Schlatter concluded that the state standard applies to background noise combined with wind noise, citing the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Commerce.

There is no Minnesota rule specifically for wind farm noise. But the general state noise regulation would include sounds from birds to nearby road traffic to wind turbines themselves — all combined, Frank Kohlasch, the MPCA's air assessment manager, said in an interview.

The Commerce Department, which represents the public interest before the PUC, has interpreted the noise standard that way since 2012, said Ross Corson, a department of spokesman. "It's not new," he said. "It hasn't been an issue."

That's largely because wind farm proposals have rarely been contested before the PUC, as Freeborn Wind has.

Schlatter's Freeborn Wind decision could have implications for the wind power industry.

"We are trying to understand the ALJ's recommendation," said Beth Soholt, executive director of St. Paul-based Wind on the Wires, a wind power advocacy group. "We are concerned about a new direction and what it would do to development."

The Freeborn Wind farm would include 42 turbines, its footprint encompassing just over 250 homes. Another 58 of its turbines would be located in Worth County, Iowa. Altogether, the $300 million project would produce up to 200 megawatts of electricity to be purchased by Xcel Energy.

The entire Freeborn Wind farm was originally slated to be built in Freeborn County. But Invenergy decided to move more than half of it across the border due to opposition from the Association of Freeborn County Landowners.

The group's antipathy was sparked partly by fallout from the 122-turbine Bent Tree wind farm in northwestern Freeborn County, which has been producing power since 2011.

For several years, a handful of residents who live next to Bent Tree complained about turbine noise. The Minnesota Department of Commerce in 2016 found their complaints to be "substantial." Two studies were then done, and both indicated Bent Tree exceeded state noise standards at certain sites. Wisconsin Power and Light, Bent Tree's owner, has questioned the studies' accuracy.

In March, the PUC took the rare step of ordering Wisconsin Power to "show cause" why its permit for Bent Tree should not be revoked.

To solve its Bent Tree problems, Wisconsin Power reached agreements in April with two persistent noise complainants, Bernie and Cheryl Hagen and Dave and Birgitt Langrud. The Bent Tree noise studies had involved turbines directly adjacent to the Hagens' and Langruds' homes.

The settlements call for the company to buy their properties — if the PUC allows an end to operating restrictions on three turbines at Bent Tree, as well as the cancellation of any further noise studies connected to the first two.

The PUC unanimously approved the settlements Thursday.

Mike Hughlett • 612-673-7003