Cara, On Feb 3, 2007, at 11:20 AM, Cara Lin Bridgman wrote:
> I thought one future problem with solar cells is that they require oil > to produce. I recently read somewhere (here?) that solar cells > require > about 60 years of use before you get a return on your investment. > Maybe > with full accounting... > I think this is based on 1970s data. Today's solar cells are cheaper but thanks to high demand from the EU and China prices are going up. With increased production polysilicon is becoming scarce and competing with computer chips. The good news is that economies of scale will reduce costs eventually and greater demand means greater usage, hopefully with reduced Atm CO2 emissions over all. More good news: A recent breakthrough has produced solar cells that can convert a broader range of the spectrum to electricity. Previously the upper theoretical limit of silicon PV cells was 36% (40% with fresnel concentration), although most commercial PV = 10-15%. Researchers from Berkley and South Africa have increased this to 50%!!! See: http://www.lbl.gov/msd/PIs/Walukiewicz/04/04_1_Walukiewicz.html Even with New England's paltry insolation this means the average house could be energy independent in the future. I'm surprised that no-ones brought up the "sun don't shine at night" or "the wind don't blow all the time" arguments. Well, I got answers for those too... > If it comes down to choosing between using oil for transportation as > opposed to using it to make solar cells, hospital equipment, > medicines, > pesticides, fertilizers, and other tools, I'm all for the tools. > > If it comes down to choosing between eating corn and using it for > transportation, I'm all for eating it. I think China recently > passed a > law to prevent ethanol from taking food out of the mouths of its > people. Roger that! It is my belief, though not yet fully supported, that farmers can produce both food and fuel by raising wind turbines and grain simultaneously. On a recent visit to the Fenner Wind Farm in upstate NY I had the opportunity to speak to one of the land owners of this 50 MW (35 turbine) agro-power facility. He reported that he receives as much from wind farm leases as he did from farming, with NO LOSS of PRODUCTION! > With regard to Paul's comments on SUV's I sympathize. A recent trip to Slovakia found Europe swarming with the cutest little 60 MPG cars you ever saw. Unfortunately corporate America has us believing that we WANT bigger, faster, and more glutinous cars. The recent gas price spike proves what those of us over 40 already knew: Only $4.00/ gal gas will ever change this on a large scale. Any of you Europeans want to sell me a Micro Car? http://www.micro-car.co.uk/themc1car.htm David Bryant [EMAIL PROTECTED] 978-697-6123
