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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."
The summary is misleading, Geothermal power plants already exist.
I don't know if this method is supposed to be much more eco-friendly, but to me it sounds like that would make it much warmer up here, on the earth's surface...
http://ww.geothermie.de/iganews/no39/guadeloupe_ge othermal_developmen.htm
A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant.
I think they should go on a trip to Iceland... Frankly...
Ahhh...the great dumpster continuum. Many a free computer will be found there. -- sowth (748135)
This will never work because, as we all know, the earth is hollow.
If an investment of $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." then we would all be getting our electricity (and probably all of our fuels would be made using electricity) from geothermal sources.
Since I have some faith in studies from M.I.T. it seems like the writers are off by a few orders of magnitude. Probably they meant $800 billion to $1 trillion?
Well they may be right that just 40% of the heat flow through the continental shield of the US may meet the energy demand 56k times over, the ticklish part is extracting the energy in an economic way. So far the only places where geothermal energy is usable is near active Volcanic areas where the geothermal gradient is steep enough to allow high temperatures near the surface and thus a high enough energy density to make the investment profitable (Think Iceland and California). All the other places the heat flow is too low to be usable for anything else than house heating.
Another thing one must address is that the heat flow can only be used where permeable strata exists in the ground making it possible to circulate water to extract the heat. In places with crystalline bedrock, the heat flow can not be used.
Yours Yazeran
Plan: to go to Mars one day with a hammer.
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.
but Wairakei here in NZ is a geothermal power generator http://en.wikipedia.org/wiki/Wairakei
It uses the natural geothermal activity local to the region.
ACK NAK RST
TFA says the goal of the project is nice, but cost is a big barrier. "A so-called hot rock well three miles deep in the United States would cost $7 million to $8 million, according to the MIT study. The average cost of drilling an oil well in the U.S. in 2004 was $1.44 million, according to the U.S. Energy Information Administration."
/ Spending.asp#USMilitarySpending US military spending was over $570 Billion in 2006. So why not spend, oh, say one percent of that figure to go towards coming up with clean energy?
Yea, so that's about six times more expensive. But wouldn't the savings be much more in the long run? And more "environmentally friendly"? After all, according to http://www.globalissues.org/Geopolitics/ArmsTrade
The Wknd Sessions - Malaysian and South East Asia independent music
Going Geothermal isn't worth the time. Not if you want to Flash rush the Core's Commander.
OK, so who let the morons out of the bag? The benefit of geothermal energy is not to reduce the amount of heat energy rejected into the envronment. ALL of the energy we use ends up there anyway. Thermodynamics and such, I won't bore you with the details.
But every ton of CO2 released into the atmoshere has a devastating effect on our lives. Not that CO2 is poisonous, but if significantly effects the absorption of solar energy. Why do you think there are record floods in South Asia, the polar ice cap is melting and huricane season is no longer simply interesting. It is because the condition of our atmosphere is changing.
Power produced by geothermal energy does end up producing heat. But it has an almost unnoticeable effect on our environment, and when it is shut off, its effects are shut off. This is absolutely not the case with fossil fuels, especially coal.
So get to know the science, and be afraid. Be very afraid.
The oldest (over a century) and largest (produces 10% of the world's entire supply of geothermal electricity) is still in Italy, Larderello. It produces more than 500 MWe.
First off, there are no such things as "stalagtites". There are only stalactites (which hang tight from the ceiling) and stalagmites (which stand mightily on the ground); from your description I presume that you mean the latter. However, both are formed by dripping water, so perhaps you mean the tufa towers of Mono Lake. But those formed underwater and were only exposed when Los Angeles started diverting water from nearby rivers and the lake's water level fell. But no matter what you mean, these projects will only effect a very thin layer of the upper-most magma. You might as well worry about an oil spill effects the ocean's currents.
Shattering rock is how the process words. Water has a hard time passing through solid rock, so the mining process initially injects cold water to form microscopic cracks in the rock for the water to flow through. In the Swiss project, the earthquakes occurred because they were injecting water into a fault, in effect lubricating things enough that the two sides of the fault line could side easier. This may be a show stopper for that project. In North America, we will probably want to avoid drilling along the Pacific Coast or anywhere near the Reelfoot Rift.
Lastly, Earth's magnetosphere is produced by its core, not the magma. And if "sucking the heat out" could cause volcanoes to "dry up", I think that most people would consider that an additional benefit, not a disadvantage.
Nothing for 6-digit uids?
Small space, high pressure. The pressure is caused by gravity -- the weight of all the stone on top of it. (The same thing causes nuclear fusion in the Sun.) It's not going to go away unless we forget to pay the gravity bill.
I piss off bigots.
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.
That's enough to power 82 flux capacitors!
I have spoken'eth.
"Apparently, scientists don't realize that the construction and maintenance of power plants and power transmission infrastructure has an environmental impact."
Sharpening a stick and running after Bambi has an environmental impact. The construction of factories, power transmission, aluminum smelting and other stuff for the fabrication of my Cannondale bicycle has an environmental impact. Your criticism in this regard is knee-jerk unthinking stupidity. You're like the SUV driving "friends of the environment" on Martha's Vinyard (Ted Kennedy, et al) that are all "save the environment" and "let's get off of oil" until it's in their back yard, citing all sorts of environmental impact from the supposed chopping up of birds to scaring away fish (seriously).
Putting up a wind turbine has an environmental impact. http://www.portsmouthabbey.org/
Picture: http://www.ebecri.org/custom/wind.turbine.html
See, the difference between people like you and the people at the Portsmouth Abbey, is that they're actually attempting to do something about our oil dependency. You, however, sit behind your keyboard whinging about how eeeeeevil any kind of activity that raises us above the caveman with a pointy stick and whacking off to hairy-armpit eco-girl porn.^1
Begone, troll.
--
BMO
1. is there such a thing?
"Geothermal" is an extremely large umbrella under which many different types of systems are developed. I am a field supervisor for a company that specializes in the development high temperature geothermal aquifers. Right now (like tonight) I'm drilling in the Ohaaki-Broadlands field in New Zealand. I'll be leaving here to return to Iceland where they've been developing the Reykjanes (Blue Lagoon) and Hellisheidi fields.
t _geo/article_1136_en.htm
This is (at least) the second time these "hot rock" systems have been mentioned on Slashdot. Each time this type of geothermal power is mentioned as being "first", it means that it is the first of its kind to be commercially viable. It involves (at a MINIMUM of 2 wells - one to inject and one to drain - for a heat transfer loop to occur from the temperature of the surrounding rock. A "path" for the water to move from one well to the other is where the "art" or science comes into play. I'm really speculating now but from what I gathered between the lines of the article was that where they drilled the injection well was along a natural fault. This would save them the cost of a "frac" job to create a path between the injection and the recovery well.
(I'm leaving out the possibility of a reverse circulation well which would pump down the outside of a tubing string and recover up through it).
http://ec.europa.eu/research/energy/nn/nn_rt/nn_r
These projects are the "first" of it's type (to be commercially viable (in the future)). Geothermal power generation has been in production (on a large, commercial scale) from the late '40s and early '50s.
The power generation wells we drill typically flow "water" at 290-315C - you can tell (on surface while drilling) how hot they get by indicator minerals and their melting points. When we drill into one of these aquifers the "water" wants to become 100C and "steam" at atmosphere - that's where the energy to power turbines comes in. I'm leaving out the "typical" production figures since this varies from country to country - some fields produce 8-10MW/well and others can produce 35-40MW/well - that's alot of power to be coming out of the ground from a single hole (usually 12 1/4" or 8 5/8")!
The wells then get tied into a pipeline system and feed a turbine generating station (after pre-plant treatment if required). This is similar to how oil/gas wells are tied into a refinery. In most cases the water outflow from these plants are re-injected into wells that are drilled for this purpose on the edge of the aquifer systems.
I just wanted to throw some point of view out there for this stuff - I can try to answer other questions related to geothermal power (since it's kinda my "hobby" now like Linux was when I was dd'ing onto 14 floppies back in '94). I didn't write the book on this stuff but I work along side the people who did.
Cheers
Another thing to keep in mind is that with an effectively infinite energy source (with non-infinite power output), lower cost does not automatically mean lower profit. The laptop I'm typing on probably has more processing power than all the computers in the world back in 1975 combined, but does that mean my laptop is the only computer that was sold last year? No, Intel and AMD are selling more processors than they ever have. Lower energy cost just means people would come up with more ways to use energy, not continue to use the same amount of it.
Hardly. Transportation energy sources have several requirements to which gasoline is well suited. Cost, high energy density (both volumetric and weight), ease and speed of distribution (refueling or recharging), and safety are some that come to mind. A cheap energy source like geothermal would take care of the cost requirement, but energy density (range) and distribution (time to recharge) would still remain a huge hurdle to electric vehicles. Also, most existing car manufacturers are at the forefront of electric vehicle development, and if they aren't they'd just buy up any electric car competitors to insure they stay competitive. Right, which is why this is, as I asserted, a political problem; not one of oil companies conspiring to hold back technology.That being said, Earth is about 6E24 kg. The specific heat of silica & iron (the two most common minerals) is .7 & .45 J/gk - average it to .55. That would mean 3E24 J for a 1 degree drop. 3600J is a watt-hour... so 2.1E19 J is a terawatt-year. That means it would take about 140,000 years of 1TW 'drain' to cool the entire (interior of) earth about 1 degree. Even assuming that all human electricity was generated via geothermal energy, it would take somewhere in range of millions of years.
So, yeah, I wouldn't really worry about it.
Have you been touched by his noodly appendage?
WTF? What's moving?
too dangerous to put a power plant
Right, cause all of Yellowstone is as dangerous as Mt. St. Helens.
any suggestion of digging great big holes is nonsense as well
Since the big holes are already working quite well, I think you're full of it.