Wind farm study analysis varies
Depending on who you ask, the recently released sound study conducted at the Shirley Wind Farm in eastern Wisconsin is either good news for proponents or good news for opponents of industrial wind turbines.
Reading the report, and talking to representatives on both sides of the issue, doesn't help clear up the confusion.
The study was made possible due to intervenor funds from the Wisconsin Public Service Commission. The funds were provided in response to Highland Wind Farm's proposed 41-turbine project in the Town of Forest in northeastern St. Croix County. The same company that developed the eight-turbine Shirley Project (Emerging Energies) is also behind the Forest proposal.
Opponents of the Highland proposal point to negative health effects of several homeowners who lived near large turbines in Brown County as a reason for the PSC to deny the wind farm's application. They claim that inaudible sound and vibrations from turbines cause dizziness, nausea, headaches and more for some people living nearby.
The recent research, which focused on low-frequency and infrasound emitted by large electricity-generating wind turbines, was conducted by four independent sound testing firms. The test results will apparently be used by the PSC as it inches closer to its decision on whether to allow the Highland project to move forward. Their decision is expected sometime in February.
The report is signed by five sound experts who conducted the study, which took place Dec. 4-7, 2012. Among the report's recommendations is further study at the Shirley Wind Farm site to get a better handle on sound and vibration emitted by turbines in motion.
When the initial testing was conducted, the sound experts found the Shirley project's current owners, Duke Power, less than cooperative. Those conducting tests said the test results would have been better had the turbines been turned on and off to establish a background sound baseline.
"We strongly recommend additional testing at Shirley," the report concludes.
The study did verify that sound levels in a home 1,280 feet away from one turbine could have caused the illnesses reported by the family that lived there. Two homes that were further away from the turbines (3,300 feet and 7,100 feet away) had limited or no low-frequency or infrasound detected by the sound tests.
"The four investigating firms are of the opinion that enough evidence and hypotheses have been given herein to classify LFN (low-frequency noise) and infrasound as a serious issue, possibly affecting the future of the industry," the report notes.
Within the Highland project, several homes will likely be just outside the 1,250-foot range of a turbine. The setback is the minimum required by state regulations, but Highland opponents claim turbines that close to occupied homes could impact people's health.
After the release of the report, the non-profit organization Clean Wisconsin which helped commission the study issued a statement noting that experts "found no evidence linking low frequency sound from wind turbines to health impacts."
Staff scientist with Clean Wisconsin, Tyson Cook, said wind farms have a long history of successful operation around the world without any documented health problems.
Cook said Wisconsin's wind siting rules were adopted by the PSC after consideration of current science regarding the appropriate distance that turbines should be placed from homes.
"The Shirley Wind Farm measurement study did not reveal any new information that would call those wind siting rules into question," he said. "There are no peer-reviewed studies showing negative health impacts from wind turbine sounds below the threshold of hearing."
The study found nothing unexpected, Cook added, and the results should not be used to stop projects that are moving through the approval process.
"It was not the clearest written report, unfortunately," Cook added. "And there's a lot of sensationalism around this issue."
Cook said that wind generation remains the nation's best and safest source of renewable energy.
"It's important that we fully understand the impacts of our energy sources, which is why we wanted to see this study conducted," Cook said. "While there is no evidence directly linking wind farms to negative health impacts, there are volumes of studies showing the disastrous impact of air and water pollution from burning fossil fuels. By moving toward clean, safe energy choices like wind, we can help improve the health of families across Wisconsin."
If there was scientific proof that wind turbines caused health problems, Clean Wisconsin would fight the installation of turbines near homes, Cook noted. But all current science points to the safety of the industry, he added.
Jay Mundinger, founding principal with Emerging Energies, issued a brief statement following the release of the report.
"We continue to believe that wind energy poses no imminent threat to people's health and safety, that current state-mandated setbacks are appropriate and that renewable wind energy remains a viable, clean source of electricity for Wisconsin."
Those opposing the Highland project read the report differently.
In a press release from attorneys working with the Forest Voice, a non-profit group of local residents fighting against the Highland Wind Farm, claims the study shows that "acoustic energy" yjay may be inaudible can "adversely impact people."
"This study makes it clear that more research is needed before the Public Service Commission should consider granting a permit for the Highland Wind Project," said Brenda Salseg, a Town of Forest resident and spokesperson for Forest Voice. "The risk of putting more families at harm is too great. Highland has five times the number of turbines as Shirley Wind."
Salseg said the state setback for turbines is too short and it's time to correct it.
"The commission's responsibility is to protect the health and safety of the public," she said. "The commission should deny the project as designed to protect the residents of the Town of Forest from the serious problems experienced by folks in the Shirley project."