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Science Forum

  1. 02 Dec '14 10:42
  2. Standard member sonhouse
    Fast and Curious
    02 Dec '14 11:52
    Originally posted by Zahlanzi
    Yeah, saw that. Half a gigawatt. It takes up a lot of real estate though, something like 6000+ acres.

    If you look at the sunlight energy coming in on a desert plot of 6000 acres, that is about 43,000 square feet * 6000 * 125= 32 gigawatts hitting the ground. So total efficiency is around 1.5% of the available energy. At least that available in daylight hours. Even getting 1/4 of that turned into electricity could yield well over a gigawatt on the same plot of ground,
    As it is, to get say 10 gigawatts would require paving 120,000 acres with solar cells. I wonder if they mean a half gig harvested over a 24 hour period? If you need 120,000 acres you are talking a plot of land about 14 by 14 miles or 22X22 Km. Even ten gigawatts is a drop in the bucket compared to the total amount of energy we use. To get say one Terawatt at that level, you would need 12 MILLION acres paved and even THAT is not enough to run the entire country.

    12 million acres would be a plot of land about 140X140 MILES or 220X220 km. You are talking significant land use at that point. Of course we have that much and more desert space available but that still leaves the problem of transporting that much energy since there is very limited high voltage lines in the desert in the US and for sure in places like Australia. An entire infrastructure has to be built to handle that much energy and the estimates for THAT project comes in at a trillion dollars or more.