The Burlington Free Press ran an article this week that is perhaps the most comprehensive look at the emerging noise issues around Vermont’s two largest wind farms, in Sheffield and Lowell/Albany. The problems at the Sheffield Wind project, which began operations in October 2011, are interesting, in that some residents live within earshot of I-91, yet have found that the sounds made by turbines 3/4 mile away are far harder to live with. (I, too, live about a mile from an interstate, hearing noise levels that are roughly the same as those I’d hear from turbines at that distance.) A retired Air Force pilot says that the turbines remind him of a jet at 10,000 feet that never goes away.
Both projects must comply with state regulations that call for maximum sound levels of 45dB outside homes, and 30dB inside homes; quarterly monitoring at four locations is required as well. The first year of monitoring at the Sheffield Wind project affirmed that it’s operating in compliance, though at least one monitoring location was close enough to the interstate that some have questioned its usefulness.
The article highlights some of the challenges facing neighbors, as well as state regulators and wind farm operators. For starters, we may again be seeing that turbine sounds of 40-45dB can be more bothersome than has been assumed, especially for people who, like one couple in the article, moved to the area “for its beauty and peace.” Also, short-term sound monitoring may not occur at the times when the noise is most troublesome; the noise issues may not be solely related to wind speed and direction, but could also be affected by the level of inflow turbulence or other atmospheric conditions. The article does not clarify how many complaints have been received around the Sheffield Wind project, but notes that 28 households have lodged formal complaints since the turbines on Lowell Mountain began operations in November.
A noise-reduction mode is available on the Lowell Mountain turbines, and Green Mountain Power is working to learn when it should be triggered. Both sound testing and complaints from neighbors will inform that learning process. “These noise issues are relatively new for us,” said Geoff Commons, director of public advocacy with the state Public Service Department. “We’re trying to figure out what the problem is. We’re trying to help.”