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The Potential of Geothermal Power

EskimoJoe wrote with a link to an AP article about progress in the development of geothermal energy. A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant. The concept is simple to understand: earth's core heat transforms water into steam, which in turn causes a turbine to revolve. The potential, though, is enormous. "Scientists say this geothermal energy, clean, quiet and virtually inexhaustible, could fill the world's annual needs 250,000 times over with nearly zero impact on the climate or the environment. A study released this year by the Massachusetts Institute of Technology said if 40 percent of the heat under the United States could be tapped, it would meet demand 56,000 times over. It said an investment of $800 million to $1 billion could produce more than 100 gigawatts of electricity by 2050, equaling the combined output of all 104 nuclear power plants in the U.S."

4 of 397 comments (clear)

  1. Ick, measurements by Anonymous Coward · · Score: 5, Insightful

    A study released this year by the Massachusetts Institute of Technology said if 40 percent of the heat under the United States could be tapped, it would meet demand 56,000 times over.

    Why do science journalists insist on giving human-unfriendly numbers like this? Is 40 percent feasible? No. Does 56,000 times hold any special significance? No. So why don't they say that 1% would meet demand 1,400 times over? It's a lot more realistic and more comprehensible for readers. Or why don't they say that the USA need only tap a thousandth of a percent of its heat to more than completely power the country? That's more relevant.

  2. Re:Misleading by jcr · · Score: 5, Insightful

    IIRC American Indians, many African cultures, and even our old agricultural society were much respectful of the environment.

    Bullshit. The American indians simply lacked the technology to have a significant impact on their environment until they got horses, at which point their population expanded and they routinely exhausted hunting grounds, and became far more mobile as a result. As for African cultures, the majority of the Sahara desert became so because of goats, which were protected from predators by humans.

    The fact is, it's the industrialized world that first became concerned about the environment, because we're rich enough to have the luxury of considering issues beyond subsistence.

    -jcr

    --
    The only title of honor that a tyrant can grant is "Enemy of the State."
  3. The question of scale by plnrtrvlr · · Score: 4, Insightful
    I've seen too many comments about the "effect this would have on magma under the earth if we cool it this way." The answer to these questions is that for a long long time, we'd have virtually no effect. The scale of human activity is just to small compared to the mass of the earth -the heat source for this power generation method. Go back to school and look at the graphics that show just how thin of an area the crust occupies on the earth. http://iga.igg.cnr.it/geo/what-is-for%20IGAnew_fil e/image038.jpg Now imagine for yourself just how thin of an area human activity would impact. The heat being used in these systems is not coming directly from magma, but instead is coming from heated rock far above those layers in the earth: heat that is already being transferred to the surface. The worst case scenario is that we might be able to "overbuild" and lower the thermal gradient for a time in a given area. In a case like this, the worst that would happen is that we would have to shut down the power plant for a time until the heat radiating up from deeper in the earth was allowed to build up again to a point where the gradient became economical for the power plant to run again. We are talking about using heat from solid rock, miles above a magma pool..... rock that is hot because of heat radiating to the surface from the earths core. We would be giving a small percentage of that heat a fast track to the surface.

    That said, I am sure that someday in the distant furure, such concerns would be warrented. I can forsee a day when the power needs of the earth and the technology is such that we would be tapping heat more directly from the mantle or core in amounts that we might be able to affect the magnetosphere by cooling the mantle/core significantly. This is not a problem for these projected plans. I would be doubtful of our ability to cool even a localized area enough that we could accomplish something like "eliminate the possibility of the Yellowstone supervolcano erupting." We have to keep in mind the scale of our activities compared to the size of the earth. Our ability to communicate only makes the earth seem to be small....

    Finally, on the subject of heating the earth: all electricty generation and consumption creates heat. We take fossil fuels from deep inside the earth and burn them, generate electricity and consume it, converting it back to heat as we do. This is all heat that would not have otherwise ever been found on the surface of the earth. Or we can take heat that is rising to the surface of the earth anyways, fast track it to the surface, generate electricity and do the consumption/conversion thing. Yes, we bring heat to the surface, but since it was on its way to the surface anyways, it seems a no brainer to me.

  4. Re:Misleading by jcr · · Score: 4, Insightful

    People are people, and trying to ascribe any characteristics to a group like "indians are more in tune with the environment" is nothing but racism.

    -jcr

    --
    The only title of honor that a tyrant can grant is "Enemy of the State."