Arizona will get non-stop clean energy from hot air drafts

Many green energy sources only generate power in a narrow range of conditions. Solar panels won't work when it's dark, for instance, and wind turbines are useless when everything is still. If Solar Wind Energy Tower has its way, though, we'll soon get clean electricity around the clock. It recently received permission to build a tower in San Luis, Arizona that produces power through hot air downdrafts; water injected at the top of the tower cools the desert winds, dragging them toward turbines at the bottom. Since it's almost always hot in the area, the plant should run all day and night for much of the year. An ideal summer day could have it churning out a healthy 1,250 megawatts per hour.

The downdraft tower should be ready for action in 2018, and Solar Wind Energy Tower hopes to license the technology to others. As you might imagine, the need for a hot climate is going to narrow the customer list -- you won't see this system in more temperate regions. However, it could be a boon to both the southern US as well as Africa, the Middle East and other places where heat is far more abundant than eco-friendly energy.