While currently only accounting for under 1 percent of the USA’s electricity, the wind industry is really starting to take off in North America, with output better than quadrupling between 2000 and 2006 .
The U.S. Department of Energy predicts that by 2020, wind energy will offset approximately 4.5 percent of the carbon dioxide that would otherwise be emitted by other sources of electricity generation.
One of the big shadows looming over further rapid development of wind farms is the effect of wind farms on humans and wildlife, particularly birds and bats.
This has also been a point of contention in Australia in recent times; probably the most well publicized case relating to a farm that was to be constructed in Victoria. The farm was going to be constructed in an area relatively close to a habitat for orange-bellied parrots, of which there are only a few hundred known to exist. The development was ultimately blocked and is still the subject of great controversy.
The wind farm and bird mortality argument is complicated by there being so little data available as to the scale of impact. As for bats, there does seem to be some evidence to suggest their populations could be adversely affected when turbines placed on ridges.
Most of the available evidence suggests the mortality rate for birds and bats from wind turbine collisions is less than five birds and five bats per turbine per year. It’s still a lot in my books – especially with some farms consisting of dozens of turbines. There’s also the question of wind farms interrupting bird and bat migratory patterns. The good news is a lot of this risk can be mitigated if farms are constructed in appropriate areas.
The same goes for the impacts on humans – negative aesthetic impact, noise and shadow flicker. With some careful planning these problems should be minimized.
Even given some of these issues, if it were a choice between coal fired power station, nuclear power facility or a wind farm I’d have to live next door to.. I know which I’d prefer.
If you’re interested in learning more about the benefits, challenges and some of the myths relating to wind power, have a read of Wind Farms : The facts and the fallacies (PDF).
How wind turbines work
Wind turbine choices