The wind-energy industry said an opinion filed by Minnesota pollution-control regulators defining wind-turbine noise will stifle its growth.
The Minnesota Pollution Control Agency (MPCA) said the state's limit for wind-farm noise applies not only to sounds from turbines but also should include background noise such as road traffic, said the filing with the Minnesota Public Utilities Commission (PUC).
The filing is part of a contentious permitting case for a proposed $300 million project southeast of Albert Lea, Minn., called the Freeborn Wind Farm, which would include 42 turbines in Freeborn County and another 82 turbines across the state border in Worth County, Iowa.
But both critics and proponents of Freeborn Wind say the MPCA's declaration would apply to the entire wind industry in Minnesota, which ranks seventh in the U.S. in wind-power generation.
The MPCA acknowledged in its filing that the PUC — and the Minnesota Department of Commerce — may have indeed interpreted the rule to mean only turbine noise.
"Nevertheless, the MPCA has historically, and consistently, interpreted and applied … noise standards for total sound," the filing said.
The wind industry has argued that the noise standard applies to turbine noise only, and it said that's the way the PUC has interpreted the rule.
"It's not logical, and there is no scientific basis for [the MPCA's opinion]. How can a developer control the noise of trees, the breeze and traffic?" said Beth Soholt, head of St. Paul-based Wind on the Wires, a group that represents wind-power developers and renewable energy advocates.