We make no apology for covering several developments in alternative or renewable energy over the last few months. Though we question the ability of renewable energy to be a significant provider of power in the US for many years, possibly decades to come, there is no question that there is a great deal of interest in the subject and metals consumption will be progressively impacted by the changing demands made from these developments.
The more cookie cutter the idea the more we like it. The reality is many of the ideas currently under development will not stand up to the rigors of the long term commercial market (and let’s face it subsidy can only last so long). But who’s to say which will stand the test of time and which won’t at this stage? So it was with some enthusiasm that we came across a new idea for solar collectors in The Economist’s excellent Technology Quarterly. One of the drawbacks of solar cell collectors is the cost of building and maintaining the collector itself. They are usually large steel structures which have to be powered so they track the path of the sun across the sky to focus the suns rays most efficiently onto the electricity generating solar cell(s). The significant infrastructure cost has been a barrier to their commercial adoption but an entrepreneurial company called Cool Earth Solar in (where else with a name like that) California noticed that the inside of one half of an aluminized party balloon is a very efficient concave shaped dish and that if the other half of the balloon facing the sun is clear plastic it could hold the solar cell at it’s center. The highly reflective aluminized inner surface concentrates the suns rays to an intensity of 400 times the background level onto the water cooled solar cell held in the center of the clear plastic other half of the balloon.
Cool Earth Solars’ balloons are 8 feet across and weigh just 2 lbs, of which only some weight is the aluminum coating. As a result, they cost just $2 each and currently have a service life of about one year. Figures are secret as to the cost of the solar cell but the firm estimates they can deliver power to the grid at the renewable energy subsidized rate of 11 cents per kilowatt-hour and still make a decent profit.
So if 300 foot wind turbines on the horizon are an unacceptable eyesore may be you will be more willing to accept an array of 8 foot balloons. Cool Earth is testing the idea with a 1mw facility this summer.