They look like foil party balloons, but they are actually very efficient solar concentrators. These solar “balloons” were developed by a company called Cool Earth, based in California, and it has just received $21 million dollars in investor funding. The company is now planning to build a 10-megawatt plant of solar balloons in the next couple years. This power plant would be comprised of 10,000 balloons, and cover roughly 80 acres!
So what exactly are these solar balloons? One half of the solar balloon is reflective mylar, the other side is clear film. The balloons are lightweight and easy to string up but rugged enough to withstand 100 mph winds, according to the company. The delicate photovoltaic technology is protected inside the balloon.
The company says:
Our system works like a conventional concentrated photovoltaic cell (CPV) system, but we are unconventional in our mechanical approach to forming and pointing our mirrors. Instead of rigid aluminum or glass structure to focus light, we use metalized plastic films and instead of ribs, trusswork, or material heft to maintain the mirror shape, we use active inflation air.
Unlike most other CPV companies, we actively water cool our photovoltaic cells to remove waste heat rather than relying on large, material intensive, heat spreaders and sinks.
You can read Cool Earth’s FAQ about the balloons here.
Via: Earth2Tech
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{ 6 comments… read them below or add one }
Problems:
Air leakage
UV wear on both mylar and clear plastic
barometric and temp changes…
How clear is that plastic? What kind of plastic? Is it recyclable?
Why raise it up with that stand?
The whole point of this approach, which you didn’t mention but which is on the company’s site, isn’t that this is higher performing or more durable (it’s neither) than most other approaches, but that it’s much less materials intensive, and therefore much cheaper per watt. Almost all the design decisions have to do reducing materials cost. For example, I’m not crazy about all those guy wires from an aesthetic point of view, but it makes more sense than a big heavy mounting apparatus from a materials point of view. Solar needs to get cheaper more than anything, and these guys are trying to do that with their less is more approach.
“we actively water cool our photovoltaic cells to remove waste heat ”
Heat = Energy
Thermal Solar beats PV for any large stationary install. It’s cheaper and the energy yield is higher.
At least another brand new approach, which could bring some new positive facts and experiences to the ‘department’ of renewable energy. It is not suitable for all situations, but why should it be?
I suspect technologies like this are going to make field’s of PV panels obsolete. But is it enough?
I think this is a great alternative to mirrors and glass.
Re: Ugly American in the electronic world heat is a byproduct of energy and heat is resistance which prevents electricity from being conducted efficiently. IN the case of micro electronics such as photovoltaic cells and computer processors, the smaller the electronics, the more harmful heat becomes.
I like the idea of water being used to remove the excess heat (I wouldn’t call it waste heat as it is usable heat, its only wasted by the user not finding a use for it), and even more like the idea of using the water that is transferring the heat away for something useful.
As John B mentioned I see maintenance and repair costs that could outweigh the materials cost savings. such as air expansion in the balloon eventually cause the plastic to weaken and break, as well as UV deterioration on the plastic, as well as plastic not being biodegradable when no longer usable.
I think there is room for a lot more improvement for this application.