Geothermal power

[unixronin]

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 mrmeval)

Comments

[sierra-nevada.livejournal.com]

There has been an ongoing problem with subsidence (http://en.wikipedia.org/wiki/Geothermal_power#Environmental_concerns) around geothermal plants.

[ilcylic.livejournal.com]

I don't understand that word in this context. Will you please elucidate?

[sierra-nevada.livejournal.com]

Subsidence (http://en.wikipedia.org/wiki/Subsidence) in this context means the ground sinks in the area around geothermal plants.

[unixronin.livejournal.com]

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.

[sierra-nevada.livejournal.com]

Oh, and that's $1/watt, or about 10x what we're paying now for power, modulo economic fuckups like CA still paying off the 1999/2000 swindle.

Last I knew, nuclear fission reactors came in at $0.03/watt, though I'm not sure that's the fully burdened cost.

[unixronin.livejournal.com]

That's the construction investment, not the operating cost.

[unixronin.livejournal.com]

Also, I just realized I typo'd by two orders of magnitude — I read "$100 million to $1 billion", decided to be pessimistic and take the high number, and typed "$100 billion".

Bad fingers. No donut!

[sierra-nevada.livejournal.com]

The usual answer to "why don't we do Y instead of X?" is "X is cheaper."

[ilcylic.livejournal.com]

Double that, and we could easily convert most transportation to electric traction without wondering where the power would come from.

It's not "where the power comes from" that's the stickler for electric transportation, it's "how does the power get there?" Recharge cycles are a bitch.

[unixronin.livejournal.com]

We're working on that. The Tesla electric sports car recharges in 3.5 hours, plugged in overnight, and it uses lithium-ion batteries. A supercapacitor power storage system could likely recharge much faster, and if there was abundant power to do it without simply changing where fossil fuel was being burned, there'd probably be enough market to get the development bugs worked out quickly.

Another thing that would help on that score would be to make the government put its money where its mouth is: Require ALL government official vehicles to be electric vehicles, and require ALL elected or appointed public "representatives" to use them whenever driving or being driven in any official capacity, defined to include to and from the office. If they HAVE to use them, they'll fund the development necessary to make it convenient for themselves.

[mrmeval.livejournal.com]

I thought proton polymer would work out but it seems to be stuck at low capacity. The things could discharge at very high amperage and charge in under 5 minutes. NEC had them.

I can get supercapacitors now that have interesting ratings but not nearly enough for vehicles. They may work for something like small items such as MP3 players.

[mrmeval.livejournal.com]

I wish I could remember who it was that detailed all the problems that have to be addressed with making and maintaining such a setup. It was someone on Baens Bar who has given good information on a variety of energy topics.

I'll post that link there and ask. They come out good but not fantastic economically unless prices for other energy sources go very high.