GREEN
07/29/2011 02:05 pm ET | Updated Sep 28, 2011

Arizona Solar Tower: Twice As Tall As The Empire State Building

A gigantic solar tower is coming to the Arizona desert. Once running, it'll produce enough electricity to power 150,000 homes.

The huge structure -- it will be twice as tall as the Empire State Building -- will cost 750 million to build. However, once completed, it will cost no money to run.