In many ways, wind power has become symbolic of environmental progress in the 21st century. Socially responsible mutual funds regularly sport images of wind turbines in their brochures. But wind power is not without its critics. Long-standing concerns over fatalities of protected species of birds – including the golden eagle at the Altamont Pass just southeast of San Francisco -- -- has prompted recent lawsuits by environmentalists that threaten to shut down one of the nation’s oldest wind projects. And fresh reports of surprisingly large numbers of bat fatalities at new wind projects in Pennsylvania and West Virginia has brought to the fore yet another blemish on wind power’s green image.

Bats are a mystery, yet they play critical roles in pest management, seed dispersal and pollination. While dead bats have been found at most wind power facilities all across the country, the mortality levels at two new utility-scale eastern wind projects located within 100 miles of each other has shocked both the wind industry and environmentalists.

The Mountaineer site near Thomas, West Virginia, has the current dubious distinction of being the world’s No. 1 bat killer, according to last year’s data, which showed an average of 48 dead bats per turbine. The wind project’s 44 turbines killed somewhere between 1,400 and 4,000 bats of six different species in 2003 and equal or higher numbers are expected from the 2004 season. The nearby Myersdale, Pennsylvania wind project’s 22 wind turbines reveal bat mortality levels nearly parallel those of Mountaineer.

In both cases, the wind projects were integrated into the highest forested ridgelines in the region, unlike wind projects in the Midwest and West, which tend to populate landscapes devoid of trees and premier bat habitat. Just as common lore suggested that raptors, with “eyes as sharp as an eagle,” would not have problems with spinning wind turbine blades, bats’ highly touted echolocation systems suggest they should be able to avoid collisions. The reality is that bat echolocation only works between two and ten meters out. Scientists also admit a virtual complete lack of knowledge of the total population of most bat species, so the impacts of these levels of bat mortality from these wind turbines is a big question mark.

Some East Coast environmentalists suggest that of all of the nation’s wind turbines in the sparsely populated Great Plains, the part of the country that boasts some of the best wind fuel in the world. The problem with this approach is the cost and hassle of building large transmission lines to bring power from remote regions to urban centers that are thirsting for more juice. Some wind projects will need to be sited near Philadelphia, Washington, DC, Baltimore and other East Coast cities if we are serious about shifting from fossil to renewable energy sources.

In the end, we all have a stake in a more sustainable energy future. Wind power is still far greener than the status quo. And the stance of the wind power industry in addressing the bat and bird issues stands in stark contrast to traditional power generation technologies, which also reduce populations of wildlife, but in less visceral ways. The wind industry has hired the nation’s top bat experts, who are already working on mitigation strategies.

Wind power is not the only solution to our energy supply challenges. But it will have to play a major role if we are indeed serious about global climate change, a creeping menace not only for our largely invisible bat friends, but the rest of us as well.