Wind Unit Sound Limits

Under final rules issued by the Vermont Public Service Board, wind-powered electric generation facilities will now be subject to certain noise restrictions. The rule sets forth ceilings on wind unit sound levels based on the size of their turbines, with the limits delineated in terms of decibels. 

Prompted by various complaints by property owners proximate to wind projects, the board said it had sought to minimize as much as possible any negative impacts on residents living near such facilities. At the same time, though, the board stated that it had been careful not to set noise level caps so low that they would interfere with Vermont's continuing efforts to reduce fossil fuel use, combat climate change, and transition to renewable energy. 

The board reported that its rule provides that large turbines (those with a capacity of more than 150 kilowatts) may not exceed 42 decibels during the day and 39 decibels at night, with the nighttime period defined as 9:00 in the evening to 7:00 in the morning. Those turbines also must be set back from the nearest residences a distance of at least 10 times the total height of the turbines, although developers were allowed to seek a waiver of that requirement. 

Medium- and small-sized turbines were restricted to no more than 42 decibels day or night. The 42-decibel limit can be waived by individual agreement as between developers and neighbors of wind generation facilities. (Board Rule 5.700)