Studies are being done to monitor the impacts of wind turbines on landscape ecology and wildlife, such as birds and bats.

According to the Ministry of Natural Resources' Ontario Wind Atlas, winds off of Lake Superior blow more incessantly than anywhere else in the province.

As the province ramps up its supply of "green" energy, the 126 turbines spinning in Prince Township are likely a harbinger of more to come -- and a storm of debate over the pros and cons of harvesting power from the wind.

When it's done "in conjunction with well-thought-out land use planning," wind is an environmentally friendly way to produce electricity, said Janet Sumner, the executive director of the Wildlands League, the Ontario chapter of the non-governmental Canadian Parks and Wilderness Society.

The process of converting the energy of spinning turbine blades into electric power doesn't release climate change-inducing greenhouse gases, smog-producing pollution or toxic nuclear wastes. Unlike hydroelectric projects, wind farms don't pollute the aquatic environment with methyl mercury, a dangerous human neurotoxin that accumulates in fish and is released into waterways when vast areas are flooded by hydro dams. And since wind farms involve a network of individual turbines, shutting one down has little effect on the installation's overall capacity -- unlike centralized plants such as nuclear reactors or hydroelectric stations.

Still, wind power is underutilized. Currently, only 500 megawatts of Ontario's 31,000 megawatts of annual power-producing capacity is generated by the wind. (One megawatt of consistent energy production will meet the annual energy needs of about 220 households.) The lion's share of the 8,000 megawatts of renewable energy feeding Ontario's 29,000-kilometrelong grid is produced by hydroelectric developments.

As a part of Ontario's plans to double its output of renewable energy by 2025, the Ontario Power Authority (OPA), the province's electricity planning agency, has made three requests for proposals for renewable power in the past five years. The first two rounds yielded 1,200 megawatts of wind power, most of which is scheduled to be online by the end of the year. Proposals for the OPA's third request must be received by the end of October and will result in the allotment of 500 megawatts of renewable power in December.

Another 750 megawatts of wind power has also been contracted as a result of the provincial renewable energy "standard offer" program that pays guaranteed, preferential rates over a 20-year term for wind, solar, hydro or biomass developments that have capacities of less than 10 megawatts and connect to a local distribution grid. A proposal to develop a 240-hectare wind facility east of Montreal River Harbour has been tabled under this program. The same incentives apply to factory, highrise or neighbourhood-based efforts in which renewable energy producers can sell power back to the provincial grid after meeting their own demands.

The process of developing a wind farm is largely proponent-driven. According to the Canadian Wind Energy Association, a non-profit trade organization that promotes wind power, this involves collecting at least a year's worth of wind speed data at the proposed site, determining the type, number and location of turbines, acquiring land use and building permits and completing a financial analysis. Any proposal with a capacity greater than two megawatts are subject to an environmental screening and permitting process that involves the Ontario Ministry of the Environment, the Ministry of Natural Resources and federal agencies.

The environmental footprint of commercial wind farms such as Brookfield Renewable Power's Prince Township installations deal mostly with matters of scale. All told, the Prince I and II developments occupy 8,000 hectares of land and the blades of its 126 turbines sweep nearly 60 hectares of airspace.

Building roads, erecting towers and installing transformer stations and transmission lines destroys forest habitat, and the noise and turbulence and vibrations of spinning turbines may alter the behavioural patterns of wildlife, said Mark Nash, the president of the Canadian Peregrine Foundation, a nongovernmental raptor protection group based in Toronto.

Nash admits that preliminary research in Ontario has shown "no evidence that (wind turbines) are having an impact on bird mortality." But a survey of a 120-turbine development in New York in 2006 estimated that each turbine killed 23 birds and 59 bats per year.

"Thirty years of wind farming in Europe have shown that turbines kill birds," said Nash. "I predict that as we get more and more of these big projects we're going to see the same high level of mortality that's been documented in Europe."

Nash is particularly concerned about the impacts of developing large wind farms in ecologically sensitive bird migration, staging and nesting areas, like much of Lake Superior's north shore. Prince Township, for instance, is a part of an important corridor for thousands of migrating birds that cross Lake Superior at the narrows between Michigan's Whitefish Point and Ontario's Gros Cap peninsula every spring and fall.

"The jury's still out on the environmental effects of these things," said Nash. "Yet there's a rush for development in some of the most critical raptor habitat in Ontario. Everyone's been sold on this technology and nobody cares about a bunch of birds."

As a part of its permit to harvest wind energy in Prince Township, Brookfield was required to commission a study of the operation's impacts before, during and after installation. Waterloo, Ont.,-based Natural Resources Solutions Inc. (NRSI) has been responsible for monitoring since 2005. NRSI field biologists collected data before the turbines went up using radar to track bird flight patterns and populations. Post-installation work has involved cataloguing dead birds at the base of turbines and recording wildlife sightings.

Senior biologist and NSRI cofounder David Stephenson said his company's work at the Prince wind farm will likely wrap-up this winter.

"Monitoring reports and mortality statistics are currently in draft and being reviewed by agencies," said Stephenson.

"We have found no evidence to suggest that the operation of turbines is affecting bird use of the area," said Stephenson, who wouldn't reveal the number of birds killed at Prince. The power-generating efficiency of wind farms has also been questioned. Each 118-metre-tall General Electric wind turbine standing atop the highlands of Prince Township contains bus-sized gearbox and generator assembly that can produce power at a rate of up to 1.5 megawatts. At maximum capacity, each turbine can meet the energy requirements of about 330 households.

But generating capacity is based on sustained wind speeds of 40 to 90 km/h. A six-month audit conducted in 2006 by Energy Probe, an international non-profit energy policy watchdog organization, revealed that, on average, Ontario's wind power installations achieved only 22 per cent of their rated capacities. And since turbines draw a certain amount of energy from the grid to operate, they are unable to produce electricity in the event of a blackout.

According to Jim Deluzio, Brookfield's general manager of Sault Ste. Marie operations, the winds coming off Lake Superior at Prince Township are better than average. He said the Prince I and II installations achieve maximum production about 10 per cent of the time and produce about 32 per cent of their rated capacity.

For many, the zero-emissions allure of wind farms outweighs their environmental uncertainties and less than perfect efficiency. Even the National Audubon Society, a bird-focused network of U. S. nature conservation groups, supports facilities that are "planned, sited and operated to minimize negative impacts on bird and wildlife populations . . . as a clean alternative energy source that reduces the threat of global warming."

But according to Sumner, it's possible to have too much of a good thing. Wind is the fastest growing energy source in the world, but an even better bet, said Sumner, would be to reduce the demand for electricity rather than continually increasing the supply.

"As long as government keeps on promising to supply more energy it will keep being used," Sumner said. "We need to be more aggressive in dealing with the demand side of the equation."