Hot rocks are a rockin’ hot climate solution

alba.jpgcharacter.jpgWhile wind and solar get the media attention of a sexy starlet, good old geothermal power is treated like an aging character actor.

But geothermal energy is, in fact, sizzling hot these days. Big-time investors from Warren Buffet to Goldman Sachs to Morgan Stanley to Google have begun investing:

In 2007, private equity firms invested more than $400 million in geothermal energy, which is derived from hot water under the Earth’s surface and can be used for space heating or generating electricity

Why the interest in a form of energy that President Bush repeatedly tried to zero out of the Department of Energy Budget? One reason is the soaring cost of conventional power, like coal and nuclear. Another is the growing awareness of just how much is zero-carbon electricity will need in coming decades.

But perhaps most important for this reemerging technology, in the 2005 energy bill, Congress finally extended the renewable energy tax credit to geothermal “which at 2 cents per kilowatt hour for the first ten years, can account for a third of the cost of a project” — and which will expire in December unless Congress gets its act together (see here)!

The U.S. currently has 3 gigaWatts (3000 megaWatts) of geothermal, one third of the world’s capacity, generating $1.8 billion electricity sales. What is the ultimate potential?

The US Geological Survey estimates the US could generate 150,000 megawatts.


A major 2007 study by MIT on Enhanced Geothermal Systems (EGS) found that it could be a provider of substantial baseload (24/7) power:

The panel thinks that with a combined public/private investment of about $800 million to $1 billion over a 15-year period, EGS technology could be deployed commercially on a timescale that would produce more than 100,000 MWe or 100 GWe of new capacity by 2050. This amount is approximately equivalent to the total R&D investment made in the past 30 years to EGS internationally, which is still less than the cost of a single, new-generation, clean-coal power plant.


Technology Review has a nice summary piece here. And you can find a lot more about geothermal here.

So add this to the list of commercial technologies that can deliver large quantities of low carbon power by mid-century. Could it be one of the 14 or so wedges we need to stabilize below 450 ppm (see here)? That seems a stretch at this point. But it could certainly be a big piece of a wedge, and that alone means it merits serious attention.

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32 Responses to Hot rocks are a rockin’ hot climate solution

  1. kim says:

    Don’t you want alternative energy sources to be sustainable?

  2. David B. Benson says:

    kim — hot rock geothermal is sustainable. Its geothermal heat for the interior of the earth.

  3. kenlevenson says:

    after reading the permafrost post I was thinking, time to buy land in the arctic…but after seeing this geothermal map maybe southern Nevada is the place to buy. Geothermal along with solar thermal – it’s the future “oil patch”. Too bad no one will be able to live there.

  4. Dano says:

    Jessica Alba is an energy source – she’s hhhawt. rrrRRRrrowr. Um…ahem.

    Anyway, I’d like to see the EROEI for this scheme. Certainly I’d like to see something in a distributed system where more individual single-family (or multi-family) are heated by pipes below the surface on the property, which I suspect has savings in distribution cost avoidance.


    BTW, after reading the comment above, I now believe the kim bot’s function is merely to spam comments, and the response output parameter keys on words repeated in the original post.

    Right, kim bot programmer?



  5. Jim Eaton says:

    In many places geothermal energy has potential. However, it is not without its own set of problems:

    Some fields can lose their heat over time
    Most fields bring up H2S and sometimes mercury
    Many smell up the region (see H2S) and are quite noisy
    Disposal of waterwater can be a problem
    If located in natural areas, the plants and powerlines can disrupt wildlife populations
    Some plants have caused increased seismic activity in the local area

    Nevertheless, if located in the right place and built well, they can be a low CO2 emitting energy source.

  6. Peter Foley says:

    How can any one that doesn’t support nuclear power plants be for the ground sourced nuclear power of geothermal energy? After several billion years the radioactive heat will be exhausted! Where is the sustainability?

    Jim Eaton, have you ever had sex with out a prophylactic, rode a bike without a helmet, or jumped off the high diving board? I hope you are practicing ZPG.

    I can’t believe my eyes, Joe Romm posted an alternative power source that actually works in the dark, without wind. Surely something this business friendly is anti-Green.

    Dano, learning curve still flat? Iceland has generations of real world experience, the granola land, California has actual Profitable Geothermal plants

  7. kim says:

    Can’t fool you, can I Peter?

  8. Jim Eaton says:

    Peter Foley, well, as a matter of fact, I’m a 59-year-old Californian, and my wife and I chose to have no children due to our concern for the environment. And some of the proposed geothermal plants in California — Medicine Lake, for example — have unacceptable impacts.

    According to the Geothermal Energy Association, a geothermal plant has a 30-year lifetime.

    What I was pointing out was that all energy sources, including those considered green, have environmental impacts. Unless you are concerned only about human beings, and not the other million of species we share this planet with, we must not forget this when looking at energy production.

    Would I rather see 10 new geothermal plants than one new coal plant? Absolutely! But where they are sited is critical.

    I also support solar power, but I far prefer covering rooftops with collectors (like my neighbors and I have done) to ripping up vast areas of our deserts (which are living ecosystems, not wastelands).

    Yes, desperate measures are needed to stop and reduce the CO2 our society is producing. But we must not destroy the planet in order to save it.

  9. Harold Pierce Jr says:

    Hey Joe!

    If you think geothermal is such a hot idea, then put your money where your is, and startup “Joe’s Geothermal Inc!.

    I really get annoyed when you PR flaks try to second guess the engineers. If they thought geothermal was technically and economically viably, then plants would have already been built.

  10. Joe says:

    “Second guess the engineers”??
    That’s a new one to me.

    Somehow I think Warren Buffet knows a tad more about making money than “the engineers” you apparently think run the world.

    It’s amazing logic to say any plant that hasn’t yet been built never will be built. I guess a PR flak like me wouldn’t understand.

  11. Dano says:

    If they thought geothermal was technically and economically viably, then plants would have already been built.


    They aren’t built YET because cheap fossil fool is easier. Let us wait ten or fifteen years when the supply is less and externalites more, then reflect on the statements of Harold for his lack of vision. Oh, wait: I think Harold is an injuneer. Never mind.



  12. john says:


    If we were to follow the mantra “…if it were so great … or if it were possible … or if it were profitable … someone would have done it already” to it’s logical conclusion, then we’d still be hurling sharpened sticks at elephants.

    And for the record, engineers are not the most innovative folks on the block … great at building stuff others conceive of, not so great at the conceiving part.

    So go sell your worn out Ayan Rand fantasies somewhere else. We’re all full up here. Besides, we know better.

    Oh, and many of you seem to think geothermal applies only to areas where superheated water is present — places like Iceland and the thermal areas of California. There is also a great deal of potential capacity in hot-dry-rock geothermal, which takes advantage of the geothermal gradient and fracking technology to create steam. As the MIT report noted, there is a great deal of potential for HDR geothermal systems. And Jim, with HDR systems, you don’t get the sulfur and trace metal pollution.

    I believe if we can drill 10,000 to 15,000 feet offshore for oil, transport it, refine it, and make a profit, we can drill on shore to 15,000 feet and generate electricity on-site profitably.

    One of the things we desperately need in a national carbon-free electricity grid is base power — HDR and conventional geothermal energy are one of the better candidates.

    With a concerted effort to develop CSP and HDR/conventional geothermal, I think we could get between 4-6 wedges of cost-effective no/low carbon base load electricity simply by tweaking currently available technologies.

    All we need is national leadership and the right policies.

  13. kim says:

    You have a chance to become a famous fool, Dano. Just stop restraining yourself as the paradigm shatters.

  14. Peter Foley says:

    Jim Eaton, Some local Geo-thermal plants have caused increased seismic activity? Too many 007 movies. Don’t smoke all the medicinal dope at one time. Wouldn’t any shift of rock destroy the pipes? I’m glad to see the child free liberals.

  15. David B. Benson says:

    Peter Foley — Jim Eaton is surely correct. Alos, the rock movement might or might not damage the pipes.

  16. Tom G says:

    Ah yes…Harold the dumb ol’ pot boiling orgamic chemist (your description not mine)…
    #1 You are not an engineer and…
    #2 Geothermal plants have already been built and…
    #3 You are dumb!

  17. Jim Eaton says:

    Peter Foley, see:

    Geothermal Induced Earthquake References

    Fractal clustering of induced seismicity in The Geysers geothermal area, California

    Geysers geothermal field in California

    Man-made tremor shakes Basel

    Geothermal Power Plant Triggers Earthquake in Switzerland

  18. Tom G says:

    A slip of the finger….
    Orgamic sounds a bit kinky…yes?
    Perhaps Harold is just a “dumb ole pot-boiling organic chemist” who has trouble understanding?….
    Been on DeSmog you have…

  19. Craig Dunn says:

    6 billion years not being renewable …that’s funny!

    Debating the issues is wonderful, and researching them so we don’t have leave everything to the engineers is even better.

    The Geothermal Education Office has a wonderful slide show education about geothermal resources and the Geothermal Energy Association and the Canadian Geothermal Energy Association also have a great deal of information about this amazing renewable energy resource. (including news and upcoming events.)

    Why does the whole world understand wind and solar, and yet geothermal is talked about so little? It likely hasn’t already been done, due to low cost electricity (3 cent/kw for dirty coal), high upfront capital costs and potential drilling risk!

  20. Harold Pierce Jr says:

    Hey Joe!

    Sorry about that, 99! What I meant to say was that there would be a great many of these plants already built and running. Hasn’t happened and it won’t ever happen.

    John says:

    “And for the record, engineers are not the most innovative folks on the block … great at building stuff others conceive of, not so great”

    Oh Really? You say that to the engineers at Boeing, and they would cut you up into little pieces and feed you to Herschel the Sea Lion, the Scourge of Ballard Locks! Herschel prefers steelhead, but he’ll eat just anything he find in the water.

    GO: and learn all about the clean diesel technology the engineers have developed.

    Enough of this nonsense! I have to do more calculations to confirm my discovery of the Pierce Pacific Oscillation. This and the PDO are have shifted into a cool phase, which could last for about 60 or more years.
    As I mentioned to Richard over at DeSmogBlog, better stock up on earmuffs and wool socks.

  21. Joe says:

    Harold — the PDO is a yawn, a tiny blip on the on-going warming trend from human emissions. On our current path, most of the U.S. will on average be 10°F to 15°F warmer by century’s end. BTW, where do you live?

  22. kim says:

    Joe, the PDO flipping explains the changing slopes of the underlying rising temperature trends of the last century. We warmed for the first third of the Twentieth Century, cooled from the Thirties to the Seventies, warmed from then to the end of the century, and are now cooling. That, and the quiescent sun, are why I’m predicting cooling for the next 30 years. Remember, there has been an underlying rising trend for two centuries.

  23. Peter Foley says:

    Micro-quakes so what, ANY seismic action detectable by unaided humans?

    Blasting in a mine causes “quakes”. Neo- Luddites have no shame.

    It is likely that the injection of fluids in the fault zone will actually lower the average max energy of the quakes as the liquid ‘lubes’ the interface.
    What was the quake history ante Geo-thermal? No damage yet in Basel. The earlier a fault releases the safer/cheaper for all. Unless one has no skin/kids in the future to worry about., is that an actual non-parody site? half baked repeat of previous post. The town averages 3- 4 earthquakes a year of greater magnitude. I’m sure there are a couple of Proto-Luddites still living in a cave out there,

    I concede partially- I don’t consider a 3.0 tremor as a quake, and I didn’t know that geothermal power could be used to reduce the magnitudes of future quakes– they should charge for the service.

    Joe. What is the increase in ocean vapor pressure with a one degree at the surface increase? In other words your 10 to 15 degree jump is impossible. Rain forest extending to the continental divide? Is there any Geological records approaching this? I know you have literally bet your career and financial future on a faulty meme. the continuing of a larceny to defraud the public out of public monies could result in a long term incarceration.

  24. David B. Benson says:

    Peter Foley wrote “… your 10 to 15 degree jump is impossible.” I don’t believe you.


  25. Peter Foley says:

    David B. Benson, Hasn’t ever happened at 1000ppm CO2 levels, max excursion ~7 degrees Total, last 1.25 million years, we’re at + 6 Degrees Celsius now. (We are in a warm interglacial phase) A ice age is much more likely then Joe’s pipe dream.
    If surface temps rose from 15 degrees to 20 average, the vapour pressure increases ~45 percent and the amount by weight air can ‘carry” increases almost the same amount—Talk about an actual temperature
    “forcing” But it is NEGATIVE feedback. More water vapour = more rain, clouds, and increased albedo = lower ground temps

    Ask a climatologist how even a 5 degree warming in ocean currents that are around zero degrees now would be effected then.
    if air temps have taken 150 years to increase ~1 degree, how long will it take to heat the oceans at ~15000 times the mass? this neglects the energy sucked up by the melting of the ice required in the fantasy scenario of + 10 degrees climate change in Ninety-two years.(~1 degree C/decade)
    Even the increase in water surface area will act as a further brake on temp increases.
    Just the black body radiation increase as temps rise to 298 degrees Kelvin from 288 K are immense.
    But my heat bill would be halved.

  26. David B. Benson says:

    Peter Foley — Possibly a units confusion. With a climate sensistivity of 3 K, 1000 ppm gives about 6 K increase. About 3.6 K is immediate and the rest takes a long, long time to come as the oceans heat up.

    However, water vapor is a positive feedback. As the air warms, the absolute humidity goes up while the relative humidity stays about constant for obvious reasons.

  27. Peter Foley says:

    JR keeps deleting my explanations of the flaw in your 6K CO2 forced increase.

  28. David B. Benson says:

    Peter Foley — Tamino runs an ‘Open Thread” over on

    We can take further discussion there and remain ‘on topic’. :-)

  29. Larry Coleman says:

    As a scientist (physicist) the variety of comments here is surprising. Some writers address the facts and evidence…others are clearly ideologues and turn the facts or cherry-pick their facts to agree with their ideologies. The ideologues know who they are. The rest of us know who they are because they also denigrate those who disagree with them. I recommend reading past them…they add nothing of value.

  30. Jim Eaton
    I respect your concern for the environmental impact of some solutions, but I have to differ with you when it comes to solar thermal plants in the southwest deserts. I understand that they will have some impact on the desert, which need to be reduced as much as possible. However I also think environmentalists are their own worst enemies at times.
    It’s said that solar thermal could power the whole country using 1% of our southwest deserts. The SciAm article says 2% of available and usable land would do it.
    But would we be powering the whole country with solar thermal? That’s not likely, as we have other power sources, and we also woudn’t want to have all our eggs in one basket.

    If we use 2/3 of 1%, 1/2 of 1% or 1/3 of 1% of the desert lands
    the impact is not as bad. It seems like all solutions have some environmental impact. There will always be tradeoffs.
    In this case, I think Joseph Romm is right, when he says that solar thermal with heat storage is the only current renewable technology that can provide base load power to replace coal plants, and on a large scale. Other than the impact on the desert, it’s clean. It’s low tech, inexpensive and ready to start building. If we want to stop the warming, we need this.
    It’s a solution that can happen much faster than building nuclear plants. Other than conservation, it’s probably the single biggest thing we can do right now.

    And we are missing the boat, while solar thermal companies from other countries are on board. even Abu Dubai

  31. Theodore says:

    Whether geothermal power is a minor contributor to future energy or a major contributor depends largely on the progress of drilling technology. If you are following the progress of the Gas Technology Institute and others in this business, you will realize that there is great potential for rapid progress in drilling very deep (10 km or more) at reasonable cost. If this can be done (a good bet) we could see geothermal become our #1 source of electricity. The major limitation on drilling depth might be the tendancy of hot rock to flow and crush any hardware you put down the hole. In this case, you could use air (despite it’s low heat capacity) to move the heat up to a heat exchanger at the surface. The energy production potential of rock that glows red hot might be commonly available in some areas. Forget about the uncertain prospects of finding hot water or steam at 3000 meters. Go deep. The fires of hell await us.

  32. msn nickleri says:

    However, water vapor is a positive feedback. As the air warms, the absolute humidity goes up while the relative humidity stays about constant for obvious reasons.