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
OTHER ENVIRONMENTAL READING
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