Personally, I will be thrilled when we–as a nation and as a world–no longer need to depend on fossil fuels for many reasons, not just the concern about global warming; however, we need to ensure that any alternative energy sources we develop don’t further damage (or cause a different type of damage) to the earth. Wind energy seems innocent enough, so I was surprised to see this article on meteorologynews.com, stating that widespread use of windmills could alter the weather.
Conflicting Scientific Reports
I have seen so many conflicting and illogical scientific reports over the years, such as global warming may cause more hurricanes after an active 2005 hurricane season and global warming may cause fewer hurricanes after a quiet 2006 hurricane season, that I don’t blindly accept every study released as fact. Having said that, the reasoning behind the possibility that windmills could alter the weather seems sound.
Wind Energy Over the Land
Wind energy drives the weather, and the purpose of wind turbines is to turn that wind energy into electricity, so these turbines effectively “capture” the wind. The presence of the large wind turbines slows the wind–friction always slows wind–so rather than the wind continuing uninterrupted over the land, it’s slowed by the windmill farm. Studies indicate that large collections of the turbines over land could slow the wind speed by 5 to 7 mph.
Wind Energy Over the Ocean
The effect of wind turbines over the oceans could be even more dramatic. Wind over the ocean blows much more freely than wind over land, where frictional effects of land, plants, buildings, etc. is much greater; therefore, it’s believed that large-scale interference of wind over the open ocean could result in different eddy patterns downwind of the turbines. Think of how snow collects in a drift down wind of a fence because the air being forced to slow can no longer support the blowing snow. Changing the wind patterns over the ocean could certainly change weather patterns.
I don’t claim to have the answers. Will enough wind farms be required to reduce the wind speed over land enough to affect the weather? Will any changes of wind patterns over the ocean be large enough to affect global weather patterns, or would it be more like a straw being stirred in a swimming pool? The possibility of windmills affecting the weather, however, has to be considered before more widespread usage is blindly accepted.
–Paul Yeager
