But the two-member panel also left the issue open to future debate with a warning there were "risks and uncertainties associated with wind turbines".
The Suncor project was the first to be challenged under Ontario's new renewable-energy approval process, which allows anyone to contest a wind-farm permit. The hearing was billed as the most thorough airing of turbine health concerns ever, with more than two dozen expert witnesses called to testify.
The tribunal decided insufficient evidence had been presented to prove wind turbines caused serious harm to human health. But it noted: "This case has successfully shown that the debate should not be simplified to one about whether wind turbines can cause harm to humans. The evidence presented to the tribunal demonstrates that they can - if facilities are placed too close to residents."
Andrew Lord, a lawyer with Toronto law firm Davis LLP, said the decision meant the case was not closed. "The issue could resurface, though for that to happen, there would need to be some serious peer-reviewed science to support the assertion that turbines harm human health," he said.
Eric Gillespie, a Toronto environmental lawyer acting for the group challenging Kent Breeze's permit, said the tribunal's acknowledgement of potential risks was a big step forward. "I think it's fair to say that rather than resolving the debate, the decision legitimises the debate."
Project opponents, said Gillespie, were looking at the possibility of appealing the tribunal's decision. There are also likely to be future challenges of wind-farm permits issued by the province's environment ministry, he added. New information is coming to light all the time, he explained, and the tribunal's analysis would help future opponents better focus their arguments. Kent Breeze is also a relatively small project, Gillespie noted. "Many of the experts that we've spoken with over the course of time point to the fact that you may well have different impacts once you move to projects of a larger scale."
Both the government and the wind industry welcomed the tribunal's decision. "It's very consistent with what we believe the balance of scientific and medical information has indicated, which is that there is no direct link between wind turbines and human health," said Robert Hornung, president of the Canadian Wind Energy Association (CanWEA).
The conclusion that it was important to focus on setbacks - how far turbines are located from homes - was one the industry was comfortable with, said Hornung.