Solar bubbles get $21M of funding

We wrote about Cool Earth Solar a few months back. Frankly, the idea seems pretty genius to me. Some folks work to squeeze every possible watt out of sunlight with ultra-reflective and extremely expensive mirrors. But Cool Earth Solar wants to make the mirror as cheap as possible, in order to squeeze every possible watt out of a every single dollar.

They're doing it by creating solar-collecting balloons. The top of the balloon is transparent, while the back of the balloon is reflective. While some of the power will be lost because of imperfect transparency and reflectivity, the "mirrors" cost exponentially less than any other solar concentrator on the market.

The rounded mirror backing focuses the sun on a small area of photovoltaic material. The result is that the same amount of sunlight can be captured with significantly less of the expensive photovoltaic material. Making the concentrating mirror cheap further reduces the costs.

Because the devices would be very light, they could be easily mounted on wire structures that would be used to keep them perpendicular to the sun's light. They're hoping to be able to produce power at roughly the costs of natural gas. With California's subsidies that would actually make it one of the cheapest sources of power available.

Cool Earth Solar is already in discussions with several utility companies about the possibility of selling power to them. The $21M in funding will likely only be enough for one pilot plant. But if that's successful, it won't take long for at least one zero to get added on to that total.

That's some seriously clever engineering right there. Lets just hope they can stand up to the elements.

Via CNet Green Tech