Solar Balloons Get $21 Million In Funding

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

11 thoughts on “Solar Balloons Get $21 Million In Funding”

  1. I am so happily impressed by all Spain has done to help meet seemingly insurmountable challenges to our very existence on this lovely planet we call earth. Future for all of us does not need be a frightening prospect. God bless you all! I hope to come visit Madrid soon. Wish me luck!? Thank you exceedingly.
    Dr. Robert Terrance Mullane

  2. Big corporations funding smaller businesses to find ways to build massive power plants to supply power to 1000’s. They certainly do not get my support. An individual that attempts to create and sell power cheaply to himself and his neighbors will be taxed, fined and finally forced to stop much like the Ma and Pop gas stations that sold gas for a quarter a gallon.
    Why pay high cost for power and taxes on the land the power company uses to create the power when every home and business has enough roof/land space of their own to make all the power they need for themselves. Why? …already answered that. Corporate America the land of the ha ha ha Free?
    This is just a generally spoken comment to let off a little hot air (excess energy) and not directed to or meant to offend our balloon friends.

  3. I like that people are trying to come up with new ways to bring in energy but really this isn’t a very viable option. A small to midsized power plant is roughly 200 – 400 MW, unless you can get more output from this method then we’re talked 1600 – 3200 acres to match that kind of capacity.

  4. Solid idea, but it will need enclosure or remote placement. In tube form, this can supply the energy requirement of any size greenhouse, especially high roof commercial units.

  5. 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.

  6. 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?

  7. “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.

  8. 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.

  9. 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?

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