April 21, 2008

Concentrated solar power balloons

Giant solar energy balloons floating high in the air may be a cheap way to provide electricity to areas lacking the land and infrastructure needed for traditional power systems. Solar balloons, designed by a team from the Technion Institute of Technology, could be used to harness the sun's energy in those remote areas. However, the Coolearth concentrated solar power balloon concept which is described after the Israeli plan is far better. Coolearth is targeting a cost 25 times less than regular solar PV.

The helium-filled balloons, covered with thin solar panels, hover as high as a few hundred metres in the air, and are connected via a wire cable to an inverter, which converts the electricity into a form households can use.

It will be about a year before the system is ready, Gurfil said. But initial research, both computerised and using a crude prototype, showed a balloon with a three metre (10 ft) diameter could provide about one kilowatt of energy, the same as 25 square metres (269 square feet) of traditional solar panels. While 25 square metres of traditional solar panels may cost about $10,000, the target cost of the balloon is less than $4,000.

Another company that is working on solar concentrating balloons is Coolearth. The Coolearth approach looks superior. Coolearth was funded for $21 million. There advantages are inflatable mirrors are 400 times cheaper than polished aluminum mirrors and their rigging uses about 60 times less steel than truss work and with minimal grounds preparation.

Here is a diagram of coolearth's system.

Each balloon, measuring two meters (6 1/2 feet) in diameter, can generate 500 watts of electricity and will eventually cost less than $2. With low maintenance and replacement costs, he believes the system will significantly reduce the cost of solar energy from the current price of around $4 per watt of installed capacity to levels where is competes directly with fossil fuel-based energy sources. They are confident that their minimum-material design and use of commodity materials will cut the cost of photovoltaic electricity in a 1 megawatt installation to 29 cents per watt by 2010. They want to install on farms. The advantages of installing in rural areas is the abundance of land that is easy to access and maintain (far easier than up on a rooftop), the ease of setting up large power plants (at roughly eight acres per megawatt of electricity.

Some background on concentrated solar power

Making homes more energy efficient with better water heaters. Could save 2400 kwh our of the total 11000 kwh used by an average US household. Better and cheaper than rooftop solar and would work well with concentrated solar balloons and other power sources.

Kitegen is the best potential wind power generation system

Electric and hybrid motorcycles and scooters


drbuzz0 said...

Without even going into the potential complications (balloons getting torn apart by wind, pulled from tethers etc)or the cost of the solar panels...

Have they actually considered the fact that helium is rather expensive and would need constant replenishment? Last time I checked it was like three bucks a cubic foot.

Helium the smallest known gas molecule, even smaller than hydrogen (hydrogen being a diatomic). It will therefore permeate most thin materials. This is why party balloons go flat after a couple days and why the Goodyear Blimp needs to be topped off with helium every month or so.

Itse said...

Based on their own site, Coolearth fills the balloons simply with air. The balloons are held in place on the ground (not even rooftops currently, although that will propably come up at some point) with wood posts and steel cables.

So basically you could say it's a new type of solar panel, a really inexpensive one.

I'm slightly sceptical about their ability to keep the balloons in the right shape over time, but it's an interesting approach in any case.

Rob said...

Perhaps the problem with helium is one reason why the "coolearth" solution is superior. That inflated balloon looks like it's just full of air - otherwise those guys would be trying to hold it down rather than tilt it up.