Hal Young sent along this photo in response to my post below about the size of windmills and the amount of land required to generate any meaningful wind power (more than 250 feet tall and a quarter acre per windmill).

Hal writes (emphasis added):

You’re right, even though I’ve seen them on the horizon plenty — I used to live near Altamont Pass, California — until you get close up it’s hard to imagine how big that really is. I encountered these trucks along the road near Ford, Colorado, last month, and I had to ponder a while before I realized these weren’t towers — they’re individual blades, two per rig.