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• Wednesday, October 24, 2007 09:59 AM

  As I said check the numbers, you don't have to look far for reality based liberal

  http://physicsworld.com/cws/article/print/30345

  "Humans currently consume energy at a rate of 13 terawatts (TW), and many experts predict that population growth and economic expansion will increase this figure to about 45 TW by 2050. Generating 20 TW of that energy with panels that are 10% efficient would, according to Crabtree and Lewis, mean installing such panels over 0.16% of the Earth's land surface. Given that only a fraction of this will be met by installing panels on people's homes, vast "farms" will have to be built in areas with significant amounts of sunshine. Attempting to build such farms in the West could, ironically, be opposed on environmental grounds." For comparison, about 1.7% of the US is paved (including parking lots). That's a lot of land. Transmission losses from a distance are between 30% and 50%.

  The efficiency will maybe be tripled over time, but higher efficiency proabably means more capital costs. According to a friend who works in solar power, the highest cost is now the flat substrate the solar cell has to go on. Window glass is an existing cost, thus industrial glass boxes are a good place to do solar. Storage at night is a big problem, another loss factor of say 3x. I didn't say solar shouldn't be a major power source but it's not enough.

  You can look up the wind maps, the places with wind are limited and often far from populations. Nonetheless, places like Nantucket sound (Sen Kennedy is a bit of a hypocrite on this one) make sense. Hawaii gets about 25% of it's power from wind now. You have to do AC-DC-AC conversion and storage to blend and phase the power.

  —bcwbcw Read bcwbcw's other letters
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