National
Wind turbines at sunset at Birds Landing, California, on Thursday, September 18, 2003. The turbines provide an alternate and supplemental energy source. (mvw) 2003
KRT
Wind turbines litter the land against a west Texas sky on the Ussery ranch in Nolan, Texas, August 7, 2006. (Jill Johnson/Fort Worth Star-Telegram/MCT)
MCT
This parabolic solar mirror in Nevada's Eldorado Valley shows how the sun's rays can be concentrated on a tube of fluid to make heat to power an electric generator.
National Renewable Energy Laboratory
Wind turbines are silhouetted by the rising sun in Nolan, Texas, August 8,2006. (Jill Johnson/Fort Worth Star-Telegram/MCT)
MCT
of 4
i
