A Skeptic Looks at Alternative Energy
It takes several lifetimes to put a new energy system into place, and wishful thinking can’t speed things along
By Vaclav Smil / July 2012
In June 2004 the editor of an energy journal called to ask me to comment on a just-announced plan to build the world’s largest photovoltaic electric generating plant. Where would it be, I asked—Arizona? Spain? North Africa? No, it was to be spread among three locations in rural Bavaria, southeast of Nuremberg.
I said there must be some mistake. I grew up not far from that place, just across the border with the Czech Republic, and I will never forget those seemingly endless days of summer spent inside while it rained incessantly. Bavaria is like Seattle in the United States or Sichuan province in China. You don’t want to put a solar plant in Bavaria, but that is exactly where the Germans put it. The plant, with a peak output of 10 megawatts, went into operation in June 2005.
... Without these subsidies, renewable energy plants other than hydroelectric and geothermal ones can’t yet compete with conventional generators. There are several reasons, starting with relatively low capacity factors—the most electricity a plant can actually produce divided by what it would produce if it could be run full time. The capacity factor of a typical nuclear power plant is more than 90 percent; for a coal-fired generating plant it’s about 65 to 70 percent. A photovoltaic installation can get close to 20 percent—in sunny Spain—and a wind turbine, well placed on dry land, from 25 to 30 percent. Put it offshore and it may even reach 40 percent.
http://spectrum.ieee.org/energy/renewables/a-skeptic-looks-at-alternative-energy/1