CoolEarth Raises $21 Million for Solar Balloons

CoolEarth solar balloon

CoolEarth, a company we've briefly covered before, has created an innovative way to harness the sun's energy. Instead of large expensive solar panels or costly concentrating mirrors, the company is using balloons made of metalized plastic films. Half of the balloon is transparent, letting the light in to be concentrated into a small high-efficiency solar panel by the concave interior. Each is 2 meters across and, depending on the source, estimates vary from 500 watt to 1 kilowatt. They are supported by cables, leaving the ground below clear and limiting environmental impact.

The company has just raised $21 million, and it says that "this is just the initial closing of the round, [it could be extended] over the next 60 days." The company closed a $1 million round of angel investing last June. Read on for more photos and details.

CoolEarth solar balloon

CoolEarth concentrators are suspended in series on support and control cables stretched between poles.

CoolEarth solar balloon

Here we can see how little support material it takes to keep the balloons in place.

"Our goal from the very start was to find a clean energy generation solution that could address the global scale of the carbon problem. We discarded everything that couldn't scale, relied on rare components, or had some other critical bottleneck. Ultimately, we developed a novel technology which radically reduces the amount of material in our system and balances labor and capital costs," said Dr. Eric Cummings, founder of Cool Earth Solar.

It is reported that CoolEarth is planning to build a solar farm in the 10 megawatt range in the next few years. It would use about 10,000 balloons over 80 acres.


Above we can better see what the insides of the solar balloon look like. Quite simple and elegant.

::CoolEarth Press Release, via ::Cool Earth Gets $21M for Inflatable Solar

For something a bit similar, see the Technion Institute's solar balloons.

See also: ::Hairy Solar Panels Could Result From Nanowire Breakthrough, ::New Compact Concentrating Solar Panels: Heliotubes, ::Solar Hyper-Concentrators: Reducing The Cost of Solar Power, ::42.8% Efficiency: A New Record for Solar Cells, ::New Solar Panels Produced at Less Than $1 Per Watt
Update: If you are interested in solar power, also check out 15 Photovoltaics Solar Power Innovations You Must See.

Related Content on