Project Development, Wind Power

When is Wind Energy Noise Pollution?

As more wind projects are developed closer to communities in densely populated areas, a number of homeowners within close range are complaining about noise. This often raises the question: “When does wind become an unacceptable source of noise pollution?”

The question isn’t easy to answer. While states and local communities set objective decibel standards for highways, airports and wind projects, “noise” is very subjective. Some people are not at all troubled by the low-frequency sound of an operating wind turbine. Others are extremely sensitive to the sound and report being in a constant state of agitation.

The small island of Vinalhaven in Maine’s Penobscot Bay offers an interesting case study. Since Fox Islands Wind installed 3 GE 1.5 MW wind turbines on the island community last fall, a group of residents within a half mile of the turbines have complained that the turbines are not only too loud, but sometimes psychologically disturbing.

While it is a small group of people being affected by the turbines, the issue has gotten a lot of attention – even attracting experts from the National Renewable Energy Laboratory who have gone to the island to study both objective sound levels and subjective reactions to the turbines.

Vinalhaven is a very peaceful, rural community. One of the main contentions of the affected residents is that the Maine state compliance levels – 55 decibels during the day and 45 decibels at night – are too loud for such a rural area. They also claim that the developer, Fox Islands Wind, misled them into believing that ambient sounds would cover up the turbines.

Even though Fox Islands Wind officials say they are in compliance with state noise standards, they are looking at some possible alterations such as lowering the cut-out speed of the machines, installing noise cancellation equipment in homes or changing out parts on the turbines.

Of course, any changes would affect the economics of the project and raise electricity prices for people on the island. For a fishing community dealing with a high cost of living and depressed prices for lobster, that could be a difficult pill to swallow. Because the vast majority of islanders strongly support the project, tension has arisen between the small number of impacted homeowners and the rest of the community.

The 45 decibel limit is lower than compliance levels for airports, factories and highways. People seem to be able to live around those. So why do wind turbines make people so angry? Well, the obvious answer – at least in rural areas like Vinalhaven – is that 45 decibels is still a significant increase in sound levels. It can substantially change the local soundscape. If that reality is not properly communicated, the agitation may increase.

But the other answer is less clear. It revolves around the quality of wind farm noise itself. Perhaps there is something in the low-frequency whooshing of a wind turbine that makes it more difficult for people to listen to.

“It’s interesting that we’re getting such high annoyance at these lower sound levels compared to other things,” says Jim Cummings, founder of the Acoustic Ecology Institute. “There’s now research going on into the quality of this noise and how it impacts people.”

Because industrial-scale wind within communities is so new, the research around noise problems is also nascent. Some onlookers like Cummings say the lack of a coordinated, objective look at the issue contributes to misinformation and mistrust of the wind industry.

Last year, the Acoustic Ecology Institute put out a report looking at the scattered nature of the research.

The American and Canadian Wind Energy Associations put together a joint study in December of 2009. The National Renewable Energy Laboratory has been giving the issue more attention, undertaking projects like the one on Vinalhaven. And there have been a few notable surveys done in Europe. But there still has been no independent, comprehensive study that has “put a lid” on the issue, says Cummings.

In the meantime, some wind advocates label people with sound complaints as “anti-wind.” At the same time, anti-wind advocates often exaggerate sound issues, saying they represent a public health problem. Without better studies and recognition of the problem, says Cummings, the misinformation and mistrust on both sides will continue.

“The reality is somewhere between,” he says.

For a detailed look at what’s happening on Vinalhaven, listen to this week’s podcast linked above. We’ll visit the island and talk with people on both sides of the issue. It’s not all bad – we’ll also look at how wind transformed the culture and economy of Roscoe, Texas.