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unixronin: Galen the technomage, from Babylon 5: Crusade (Default)
Unixronin

December 2012

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Sunday, August 5th, 2007 04:07 pm

100 gigawatts of geothermal power for a $100 $1 billion investment, with no associated carbon load and no radioactive waste storage problem, sounds pretty damn good to me.  According to this article, we'd only need to tap 0.0007% of the shallow geothermal heat beneath the United States (where "shallow" is 3-4 miles) to meet the US demand for electrical power.  Double that, and we could easily convert most transportation to electric traction without wondering where the power would come from.

Now this is sustainable energy.  Individual sites may cool and need to recover, but over the long run, geothermal heat will outlast the human race.  Even if we manage to somehow exhaust all the shallow geothermal sources, it'll take us long enough that by that time we may be ready for a mantle tap.

Edit:

I read "$100 million to $1 billion" in the article, decided to take the high number to be safe, and fluently typo'd "$100 billion".  Corrected above now.  That makes the construction investment on the order of one cent per watt.

(Article pointer from [livejournal.com profile] mrmeval)

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Monday, August 6th, 2007 03:28 am (UTC)
Subsidence (http://en.wikipedia.org/wiki/Subsidence) in this context means the ground sinks in the area around geothermal plants.
Monday, August 6th, 2007 03:53 am (UTC)
I suspect that depends on how they're doing it. A lot of the geothermal plants built to date have worked on the stupidly simple plan of building a plant that sits atop a geyser field and extracts superheated groundwater, and, well, yeah ... one would expect subsidence.

I'd be really surprised if there were any surface subsidence issues associated with drilling a four-mile-deep borehole into a zone of hot rock, pumping water down it, and running the steam that comes out through a turbine, when we haven't experienced surface subsidence from drilling a two-mile-deep borehole into oil-bearing rocks and letting pressure force the oil out.