GRANITE FALLS – The Minnesota Public Utilities Commission has approved a permit for the construction of an 18-turbine, 44.6-megawatt wind farm in Chippewa County.
The PUC approved the permit for Palmer’s Creek Wind Farm on a 5-0 vote at its meeting May 11, according to Dan Wolf, executive secretary to the commission. The permit includes requirements that project developer Fagen Engineering of Granite Falls update an avian and bat protection plan, as well as a shadow flicker report, noise analysis and microwave beam study. The wind farm site is located between microwave relay towers in the region.
Construction of the wind farm will likely begin in 2½ to 3 weeks, according to Mike Rutledge, director of regulatory affairs for Fagen Engineering. The turbine towers and blades for the project are currently stored near the project area, but there remains administrative work with state regulators before the actual work can begin, he said.
The project will include two 2.3-megawatt turbines on 262.4-foot towers and 16 2.5-megawatt turbines on 295.2-foot towers. The towers will be erected over a 6,150-acre area north of Granite Falls in an area parallel to the Minnesota River Valley and Chippewa County Road 5.
The permit includes a requirement that the company retain an independent consultant to monitor bat and avian fatalities at the site for three years after operations begin. During the first year, the monitoring includes a requirement that vegetation be mowed within a 60-meter radius of 10 of the 18 turbines, including the four located nearest the Minnesota River bluff. Keeping the vegetation down will assist in identifying avian and bat fatalities attributed to the turbine operations. In order to reduce avian and bat fatalities, the permit also includes requirements that call for feathering the turbine blades at certain wind speeds – turning the blades into the wind to reduce surface area.
The permit was issued after the company agreed to move the four turbines nearest the river bluff a few hundred feet away from it. The original plans had the four turbines closer to the bluff.
The Minnesota Department of Natural Resources had expressed concerns about the turbine placement near the river valley and bluff. The DNR considers the wind farm a “high-risk” site due to its proximity to the river valley and the consequent potential for bat and avian fatalities.
The river valley is an avian flyway, and studies conducted as part of the permit application identified a high population of bats and avian species in the area, including some bat species considered rare in Minnesota.
Fagen Engineering commissioned assessments of the wildlife and native vegetation in the area, as well as the avian and bat populations. Fagen Engineering also undertook studies concerning microwave beam interference in the project area, potential noise and shadow flickering – a pulsating effect when rotating wind turbine blades move between the sun and an observer.