The Minnesota DNR updated their best management practices for Wind Energy!
As it is unknown the extent to which the wind industry voluntarily follows any recommendations for feathering, the ONLY way to protect our bat population is to require similar restrictions on the hours of operation via our local Township Ordinances.
Minnesota Department of Natural Resources
Guidance for Commercial Wind Energy Projects – Updated July 2018
[Excerpts] Full Document “The DNR supports the following language that the PUC has included in recently issued site permits: “The Permittee shall operate all facility turbines so that all turbines are locked, or feathered, up to the manufacturer’s standard cut-in speed from one-half hour before sunset to one-half hour after sunrise of the following day, from April 1 to October 31 of each year of operation. All operating turbines at the facility must be equipped with operational software that is capable of allowing for adjustment of turbine cut-in speeds.” Feathering below the manufacturers recommended cut-in speed is anticipated to reduce bat fatalities by 25-35%. This standard should also be applied to existing projects that are being repowered.”
“The DNR recommends appropriate setbacks be established around wetlands that are large enough to provide a significant amount of habitat that would attract birds or bats to the area. Locating turbines or other infrastructure near these wetlands may result in avian avoidance of the habitat or may increase avian and bat fatalities. Avian avoidance of wetlands occurs when birds are stressed due to the turbine height, noise, shadow flicker, or use of an access road and they no longer use the habitat for resting, feeding, or nesting. Avian and bat fatalities occur when they strike the turbine or by barotrauma (Baerwald et. al. 2008).
Buffalo Ridge fatality studies indicated turbines with avian fatality were significantly closer to wetlands (1430.45 feet) than turbines without avian fatality (1,948.82 feet) (Johnson et al. 2000). Vonhoff (2002) recommends turbine placement at least 1,640 feet from bodies of water, riparian habitats, and forest edges.
The presence of rare species will also be considered by the DNR when making avoidance area or setback recommendations. These setbacks may be reevaluated as the PUC permitting process proceeds if more information on sensitive resources associated with the area becomes available or as the project becomes more defined.
Recommended Studies and Field Surveys
The Minnesota DNR also has an informative section on recommended Studies and Field surveys, many would be good additions as required studies in local ordinance permitting, along with the setbacks and restrictions to protect those areas identified.
Minnesota Biological Field Surveys
In many cases, there are substantial gaps in the knowledge needed to fully evaluate the potential impact of wind development on natural resources. The DNR may recommend to developers, PUC/EERA, or other regulatory agencies that biological field surveys be conducted for some sites.
Bat and Avian Fatality Monitoring
Avian Grassland Surveys
Avian Wetland Use Surveys
Avian Flight Characteristics
Avian Habitat Avoidance Studies
Greater Prairie Chicken and Sharp-tailed Grouse Surveys
Bat data collection
Native Prairie Surveys
via Minnesota DNR Guidance for Commercial Wind Energy Projects – Updated July 2018
(Also see requirements https://mn.gov/commerce/energyfacilities/)