I am at a loss as to why so many otherwise intelligent folks in the 'green' movement are fixated on photovoltaic solar cells as being the best way to convert energy from the sun.
Photovoltaics, even the nano,flexible and so forth - are just too expensive, compared to alternatives. Yes, photovoltaics are simple, and simple can be good; but not always. Here is a nice small solar Stirling demo - http://www.youtube.com/watch?v=7Q4UENGN_Yk You can take the best thin-film nano solar prototype photovoltaic cell- and project its lowest possible cost - and yet it will still be a factor of (2-10 times; depending on which accountant does the analysis) MORE costly, and therefore less effective as a workable solution, than the solar stirling - especially in mass production. Both the starting raw materials for photovoltaic cells, and the required lithography process are FAR too expensive; PLUS the Stirling can drive a 120 volt AC alternator, eliminating another costly component. This is where KISS has a double meaning. Keeping it simple, like solar photovoltaic, is real stupid IMHO because the unwarranted empahsis and VC money being poured into this dead-end keeps money away from better solutions, like the solar Stirling. In a perfect world, the DoE would be converting an old GM plant into a million unit per year solar Stirling plant. If you want a KISS pronouncement for solar energy that does make good sense, here is one: Nothing for collecting solar energy beats a mirror ! ERGO whatever complex device can use mirrors to the greatest benefit, will be the better solution. To be precise, one could put Michael Foster's Fresnel lens into the low-cost category, along with mirrors; and yes, you could use photovoltaics with Fresnels or mirrors - but AFAIK, that is still less cost effective than the solar Stirling. Jones
