>From Jones: > These [solar] cells might achieve 40% at noon in July > after being cleaned, yet only 10% at 9 am in December > with the normal coating of grime which silicon picks > up rapidly -plus- the main point is that they are > extraordinarily expensive compared to ponds and > plumbing (for CO2). > > NREL has reported tank grown mixed algae strains which > can surpass the 40% efficency figure anyway, and > generally algae will continue to multiply for several > hours after the sun goes down. > > The only comparison which counts in the least - > therefore, is this: > > How much net energy, averaged over a full year, can be > captured and stored per dollar of investment, less > incremental costs. > > Under these criteria, which are the only ones which > matter, it would not surprise any expert if the > advantage of algoil over advanced silicon solar-cells > turns out to be in the range of 50 times more energy > returned per dollar of investment. > > Jones
Jones makes an interesting point about the vulnerability of solar cell technology under certain seasonal conditions. However, what's not clear to me is what would algoil be doing under equivalent conditions at 9 am in December, when temperatures are hovering around 15 - 25 degrees F, or less. In the northern hemisphere the little critters would have already endured in excess of 12 hours of darkness (no photosynthesis) and sub freezing temperatures lowering their over-all body temperatures. I get the impression that they would work like gangbusters during the summer months. However, during the winter months I would be concerned that they might actually turn into a liability. Jones claims they could possibly end up producing 50 times more energy returned per dollar of investment compared to solar cell technology. I'd like to believe that, but I remain a tad skeptical. Oh, what the hey. I guess when it comes down to the basics, five to ten times more "energy returned per dollar" would be nothing to sneeze at either. Regards, Steven Vincent Johnson www.OrionWorks.com
