- National Wind Watch: Wind Energy News - https://www.wind-watch.org/news -

Scituate resident seeks state regulations on turbine shadow flicker

SCITUATE – A neighbor of the 390-foot-tall wind turbine on the Driftway is pushing state officials to require turbine owners to install technology that would shut down the machines when shadow flicker is detected.

While state regulations limit turbine noise, there is no limit on shadow flicker: the rotation of turbine blades causing alternating periods of shadow and light on surrounding buildings.

A group of residents have complained that their health is adversely affected by the noise and shadow flicker from the turbine, which is owned by Scituate Wind LLC, a partnership of Palmer Capital and Solaya Energy.

A January 2012 wind turbine health impact study ordered by the state Department of Environmental Protection and state Department of Public Health concluded that there is limited evidence that exposure to prolonged shadow flicker negatively impacts health.

Despite that finding, people who live near the Scituate turbine have said their symptoms, including headaches and nausea, disappear when the turbine is off for extended periods.

Tom Thompson, a Gilson Road resident and executive director of a group called the Alliance for Responsible Siting of Alternative Energy Installations, recently sent a letter to the commissioner of the state Department of Environmental Protection and secretary of the Executive Office of Energy and Environmental Affairs asking that they mandate the installation of flicker control technology.

Control systems monitor sunlight and shadow, and turn off the turbine when the strobe effect could occur, Thompson said.

While the health impact study found that shadow flicker does not pose a risk, it also suggested that flicker be allowed to occur for no more than 30 minutes per day or 30 hours per year.

Matt Kakley, a spokesman for the Massachusetts Clean Energy Center, said there is no set standard for acceptable amounts of shadow flicker. Instead, individual communities establish regulations, he said. For example, the board of health in Bourne declared flicker a nuisance.

If turbine owners are required to install strobe control systems, the arbitrary guideline of 30 hours per year will no longer be relevant, Thompson said.

“Mandating the owners to install the technology would take the guesswork out and shut off the turbine until the conditions no longer exists,” said Thompson, who had not heard back from state officials as of Monday.

Kakley said flicker is easier than other effects of turbines to predict and mitigate, as it’s largely based on the angle of the sun and other conditions.

“It’s easy to mitigate knowing that at this time, provided it’s sunny, a house would experience flicker, so there’s a timeframe for shutting a turbine down,” he said.