[ExI] EP and Peak oil.
Eliezer S. Yudkowsky
sentience at pobox.com
Wed Apr 2 17:27:55 UTC 2008
Keith Henson wrote:
> On Mon, Mar 31, 2008 at 1:37 PM, John K Clark <jonkc at att.net> wrote:
>> Right now
>> it would take a solar panel the size New Jersey to replace the energy
>> dispensed by just 100 gas stations.
> It isn't a large state, in fact it's ranked 47th out of 50 in area.
> Still it's 22,608 sq km. From Wikipedia, "or 0.45 - 1.35 kWh/m²/day"
> from sunlight for 15% efficient solar cells. Using the lower number,
> that's 0.45 GWh/square km/day or 10,173 GWh/day, for a solar panel
> that size or 3,713,364 GWh/year.
> "The U.S. used about 510 billion litres (138 billion gallons) of
> gasoline in 2006." 100 stations out of 20,000 would pump about 2.25
> billion liters. "Gasoline contains about 34.6 megajoules per
> liter(MJ/l)" That's 88,230,000,000 MJ/year or since "1 MJ = 0.278
> kWh" 24,527,940,000 kWh/year, or 24,528 GWh/year. At 50% conversion
> efficiency electricity to liquid fuel, it takes about 50,000 GWh/year
> to supply 100 gas stations. That's about 1% of the output of a NJ
> sized solar panel.
That figure sounded a little odd. Thanks for checking, Keith.
> None of these are renewable. There was an interesting article in New
> Scientist in Jan that makes the case we are within 25 years of peak
> coal. Even with breeder reactors you run out of fissionable fuel in
> less time than you would think. Part of the problem is the amount of
> energy you have to feed into getting a unit of energy out. When you
> get down to mining granite for uranium, it's close to 100 percent
> being fed back.
How long does it take to run out of uranium? 40 years may not be
enough time for fusion, but it's enough time to switch to thorium or
solar satellites (and probably enough time to build AI, but let's
leave that out for now).
Eliezer S. Yudkowsky http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence
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