Powering the Planet With Sun-Harnessing Balloons

http://discovermagazine.com/2008/oct/19-powering-planet-with-sun-harnessing-balloons

A few years back, a group of West Coast engineers were puzzling over a practical way to tackle the problem, looking for a hydrocarbon-free, clean, and renewable energy system that required no major technical breakthroughs and could be put to work in the next few years. The result: the start-up Cool Earth Solar, now based in Livermore, California, and its new-think technology, an inexpensive plastic-film balloon a bit over eight feet tall. Millions of these balloons could hover low over the landscape, each concentrating sunlight onto a photovoltaic cell inside, and pumping out electricity more cheaply than power from fossil fuels, the company says.