Environment & Energy
Related: About this forumGeothermal Power to The People: Forget Iceland, Hot Rocks Are Everywhere
By Mark Halper, Contributor
May 29, 2012
When British geologist Ryan Law lined up to meet the Queen in Exeter, England, earlier this month, he did something not everyone would do: He showed her a drill bit....
The Common Man's Geothermal
The concept is called EGS, which stands for engineered geothermal systems, or, according to preference, enhanced geothermal systems. Some people refer to it as hot dry rocks, others as deep geothermal.
Perhaps an even better name for it would be geothermal power for the rest of us, because it allows you to build utility-scale geothermal electricity and heat stations almost anywhere. Unlike conventional geothermal places think Iceland EGS does not require dramatic, bubbling geology full of volcanoes, fault lines, lava and near-surface heat.
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Rocks Star
You can do it almost everywhere, claims Horst Kreuter, CEO of GeoThermal Engineering GmbH, a Karlsruhe, Germany, consulting company that is not affiliated with Laws firm. You can do it in sandstone, you can do it volcanic stone, you can do it in any brittle rock.
In the U.S., a 2007 study by MIT for the U.S. Department of Energy, entitled The Future of Geothermal Energy, concluded that the country has enough EGS potential to theoretically meet 2,000 times its primary energy needs, and that realistically, EGS could contribute 10 percent of its electricity by 2050...
More at: http://www.renewableenergyworld.com/rea/news/article/2012/05/geothermal-power-to-the-people-forget-iceland-hot-rocks-are-everywhere?cmpid=WNL-Wednesday-May30-2012
Kolesar
(31,182 posts)It was reported in Homepower Magazine about five years ago. My impression was that one could use a modest amount of electricity and a heat pump to bring the heat to the surface.
damyank913
(787 posts)...how many kilowatts will be consumed for the operation of the plant. How many kilowatts will the pumps alone use to pump water 3 miles up and down? Worth a try I suppose.
madokie
(51,076 posts)to keep that flow going. Since this is a closed loop system the only energy you'd have to input is the energy to make the water flow which isn't much and the amount lost in the restriction of the piping. In the summer it would be more than in the winter because in the summer you'd have to overcome the small difference in the temperature of the water, warm water is lighter. In the winter that would be reversed as you'd be bringing up warmer water so you'd recoup most of that lost energy you expended during the warmer months lifting the cooler water up.
The end result would only be a fraction of the energy used to directly heat or cool the home whichever the case may be for a big energy savings overall.
damyank913
(787 posts)...which also means 3 miles up. I gotta believe that the energy input to pump water, or some some glycol mixture, six miles, would be considerable. For a plant output of 10 MW, I just don't know if that's worth it. Maybe that will be the new world model. Small plants located all over the place. I'd sure like to see the numbers. I still think it's worth a try.
immoderate
(20,885 posts)The weight (force) of the water on the down side balances the weight of the water on the up side.
Think of the force necessary to lift on person on a see-saw. Then consider the necessary force to raise one if it's balanced.
--imm
kristopher
(29,798 posts)Wind and solar are variable sources of generation, but they are going to provide the bulk of out power in the future. A distributed renewable grid will be organized around that variability and distributed, small-scale, responsive sources of generation like this and our large amount of undeveloped, small scale hydro.
kristopher
(29,798 posts)NickB79
(19,114 posts)I understand the pumps and such would have to be replaced periodically as general maintenance, but do the pipes underground corrode over time?
Things like this give me some hope that we as a species can at least maintain pockets of advanced civilization even in the face of climate change, mass extinctions and the depletion of fossil fuels.
kristopher
(29,798 posts)Last edited Sun Jun 3, 2012, 11:44 PM - Edit history (1)
As I understand it, the wells last a couple of decades before being abandoned due to cooling of the stone. I've heard nothing about corrosion, but I'd be interested in hearing about anything you find on the topic.
Basics for anyone interested.
http://www.google.org/egs/
http://www1.eere.energy.gov/geothermal/egs_animation.html