SCITUATE — For some residents of the Driftway, Scituate’s wind turbine will cause more than 60 hours of shadow flicker per year, a study report says.
The eight Scituate homes most affected by shadow flicker experience more than 10 hours of flicker per year, according to the study, which was presented to the town’s selectmen Tuesday.
The company that did the study, EAPC Wind Energy of Vermont, determined that one home will be exposed to 69 hours of the strobe-like phenomenon per year, and two others will be exposed to more than the state-recommended maximum of 30 hours.
EAPC used a combination of weather records and data collected from receptors to project how much shadow flicker will occur.
Shadow flicker is the term for alternating periods of light and darkness caused by a wind turbine’s rotation.
The angle of the sun determines where a turbine’s shadows fall, but when it comes to measuring shadow flicker, the amount of sunlight let into a home is less important than the number of hours per day the turbine runs, according to the study.
“We found that the size of a receptor doesn’t make that much of a difference, but the hours the turbine is operational makes a huge difference,” said Chester Harvey, Geographic Information Systems specialist for EAPC Wind Energy.
Since 2012, some Scituate residents who live near the town’s turbine have complained of headaches, nausea and trouble sleeping. Some brought their concerns to the State House in July.
Though a state-mandated health impact study did not link shadow flicker to health problems, it advised that people not be exposed to more than 30 hours of flicker per year.
The selectmen briefly discussed several possibilities, including technology that would shut down the turbine when shadow flicker occurs.