The Public Service Board has released its interim sound standards for commercial wind projects.
After setting standards on a case-by-case basis, the board, for the first time, established uniform limits on how loud wind turbines can be.
Over the coming year, the board will work on the state's permanent wind sound standards. And a wind project pegged for the southern Vermont towns of Windham and Grafton could become one of the main proving grounds for the new rules.
Gov. Peter Shumlin vetoed a controversial energy siting bill earlier this year, because he said provisions dealing with wind turbine noise would have put the brakes on renewable energy development.
When lawmakers hammered out a new bill, they directed the Public Service Board to come up with the interim sound standards within 45 days.
Addison County Sen. Chris Bray wrote the energy siting bill and he says the interim sound standards give both sides of the issue a starting point to work on the permanent rule.
"I think they're clear. They're well articulated. They capture the understanding of the board at this moment in time," Bray says. "In a way, what we're seeing now is everyone is putting their cards on the table and that is going to be helpful in terms of people understanding, regardless of where you are again, how we're looking at rule-making around sound."
During a heated debate in the Statehouse around siting energy projects, the sound standards proved to be one of the hottest issues.
It's extremely complicated to agree on a way to measure sound. It's also very expensive. And when a company is proposing a project, the best they can do is make assumptions about how noise from the turbines will travel over distance, through foliage and over hills and valleys.
And Bray says when wind energy supporters and critics sit down at a table, there's usually a wide gap between them.
"I have no doubt that both parties are telling the truth just as they see it and experience it," he says. "And so, our job is to try to look for reasonable ways for all of us to get along and make this work."
If it works, it will be tested in the southern Vermont towns of Windham and Grafton.
The Spanish energy company Iberdrola Renewables wants to put up 28 wind turbines, each almost 500 feet high, on a plateau that straddles both towns.
It would be by far the largest wind project in Vermont.
As complicated and controversial as it is to settle on ways to measure and model wind noise, the debate over how that noise affects human health gets even stickier.
David Acker is a member of the Grafton Planning Commission, and his house is high on a hill directly across the valley from the proposed wind development.
Acker says with so much money behind energy development, human health impacts are simply ignored.
He says there are appropriate sites for commercial wind development, but a plateau that rises between two small towns is not one of them.
"There is government information out there saying this is a problem, but the industry wants to push it to the side, and they don't want to look at this," Acker says. "They say there is no scientific proof. I disagree with them. I don't know why it is that they get to make the rules. I think it's up to the people to decide what's best for them."
Iberdrola spokesman Paul Copleman says the company is paying close attention to how Vermont develops its new sound standards.
Both towns are considering public votes on the project in November. If the wind project wins support, then Copleman says the company will file for a certificate of public good some time in 2017.
"Building a wind farm is obviously a change, and we understand that," Copleman says. "We want to listen to community concerns. We want to listen to the types of questions that we're getting when we talk to people, when we interact in the community and address those concerns. And for whatever reason that sound is a concern that a lot of people want to talk about, then we have to build a site that takes that into consideration."
Even though there's uncertainty over how Vermont will adopt its permanent sound standards, Copleman says the company is moving ahead with its planning.
"We have to trust the science. We have to keep moving forward," he says. "We have to continue to evaluate for sound, and we have to pay close attention to the process as it moves forward. But certainly that doesn't preclude us from thinking that this is a great site for a wind farm for any number of other reasons. And based on the modeling we've done so far, we are optimistic that even with new sound standards, this is a great site."
Annette Smith, a critic of the commercial wind industry, says the interim sound standard that was released doesn't bode well for the permanent rule-making process that will take place.
Smith says the interim standard is actually a step backwards, because it says inside sound should be measured under the assumption that windows are closed in the winter, and Vermonters, she says, open their windows in winter.
The interim rule also says sound should be averaged over an hour, so if there are high peaks between lower volumes Smith says there are real impacts to people both inside and outside their homes.
"So basically they have catered entirely to the wind industry and done absolutely nothing to protect our citizens," Smith says. "This was my worst fear."
Smith has worked with families that live around existing wind sites in Vermont.
She says it's disappointing that the Public Service Board ignored testimony from people who say the wind turbine noise is making them sick.
"I have written and submitted many, many, many, many documents on this topic," Smith says. "We participated in everything the board has ever done on this issue. There is no reason to expect anything good will come out of this Public Service Board. And the fact that they actually just made it worse is such a revealing thing for Vermonters."
The Public Service Board is expected to open up a new docket to begin gathering testimony on the permanent sound standard.
The new rules are expected to be finished before July 2017.