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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
Well, usually I'm all for reducing my carbon footprint, but I've learned one thing from the movies, it's that drilling a hole in the Earth's core is bound to lead to some kind of trouble. Earthquakes, giant mutant ants, ancient evil squids... just about anything could happen.
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.
But it sounds like that is what they're proposing. As far as I'm aware, the natural flow of geothermal energy from below the surface is only 45 TW, and the world already using close to 15 TW, so the total available is 3 times world energy use, not 250,000 times ???
Energy: time to change the picture.
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?
No chance. We have a few in New Zealand. The difference may be how deep they are willing to drill for it....
I could do with some geothermal heating right at the moment..... brrrr. Cold.
Here in New Zealand we've had geothermal power since 1958..
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http://www.ew.govt.nz/enviroinfo/geothermal/energ
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.
I'm not of the global-warming alarmists, but if you take stuff from a layer that's beneath you, and you pump it to a layer that's above you (which is what you do with coal, oil, uranium, and geothermal power plants) then you always change something in the environment. You displace heat. Or potential heat. Or waste products from heat. In other words, there's no way that this has no impact on the environment, it just has a lot _less_ impact on the environment.
Religion is what happens when nature strikes and groupthink goes wrong.
"could fill the world's annual needs 250,000 times over with nearly zero impact on the climate or the environment"
Apparently, scientists don't realize that the construction and maintenance of power plants and power transmission infrastructure has an environmental impact.
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
actually I live less then half a mile from a Geothermal system:e newables-schools/case-studies/geothermal/page22986 .html
http://www.dti.gov.uk/energy/sources/renewables/r
I feel a dubious sci-fi film about sucking all the heat away from the Earth and the planet breaking up coming along (the Core 2?)... surely there must be some side effects?
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
a geothermal power plant is fundamentally flawed because your attempting to build a static structure on ground which is moving all the time, and it's geological activity is the very thing you need it for. the vast majority of such sites where there is enough thermal activity to make it worth while it would be too dangerous to put a power plant, and you can't just have a couple of power stations supplying the world.
any suggestion of digging great big holes is nonsense as well.
If you mod me down, I will become more powerful than you can imagine....
Something i always think about when it comes to eco friendly enery such as this, wind-power, wave-power etc is: if we remove the heat, wind, wave - energy - from one place, are we not in fact altering the balance somewhere?
In this case, maybe this "geoheat" is part of a vast chain of effects and things relying on eachother, I'd be surprized if it was just laying there in a big void.
BUT - it sure sounds promising though!
Waiting for you by the bridge
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.
Never mind, it turns out that the summary is up to its usual (misleading) standards. If one can remember when Slashdot was a useful source of news then one is getting old...
In cold regions, near the ocean, like Canada's arctic, the sea is much warmer than the ambient temperatures which go as low as -50C. A heat pump from the ocean to buildings is quite a feasible way of exploiting geo-thermal power. One lays a pipeline instead of drilling downward. Even if they just surrounded the buildings with a blanket at sea temperatures, they would cut heating costs greatly. This would actually help global warming a bit by cooling the sea slightly.
A problem is an opportunity http://mrpogson.com
Zonk is here to promote Australia.
It's what he does! It's all he does! Who is in authority here?
Oh, he's also here to post lots and lots of dupes.
"Zonk for President. Because you thought it couldn't get any worse..."
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.
I know this deals with steam powered generation, but I can't help remembering the article that was on /. a while back about converting heat to sound to electricity. I wonder how well that'd scale, if it came to burying a whole bunch of the converters.
(I'm no physicist, armchair or others, but I'd love this explained to me in nice simple small words :)
I thought for a long time how great geothermal must be, then I thought about the possible drawbacks and long term effects.
For instance, ever heat glass up and shove it in a tub of water? It shatters. Rock 3 miles under the earth, under pressure from all the rock above it, and heated from the core is probably just as brittle as glass. The article did mention earthquakes.
Also what effect would this have on the magma flows below the rocks? I would imagine a geothermal cooled area might create stalagtites around the cooled area, much like the lava vents on the bottom of the sea floor, but in reverse. These cool stalagtites spread all over the earth would certainly have an effect on the magma flow.
With the magma flow change, what effect would that have on the Earths magnetosphere? What about other volcanic areas? Would they suddenly dry up because we're sucking the heat out from somewhere else?
On the surface geothermal looks great, but what about underneath the surface? We don't even know if there is long term effects at this point.
...where are to going to get water from in the middle of a desert???
Now how do I pipe it into the tank on my Prius?
I have a feeling that this will have negative effects if we take it too far.
Is it some left-over effect from when the Earth was formed, and thus subject to forever growing colder? Or is it from some effect that will keep on replenishing the heat?
Also, does anything bad happen if we accelerate the cooling of the core?
Waste of time. You need to turn water into steam to drive a turbine at what efficiency? With a big enough Sterling engine, I can achieve Carnot efficiency (theoretical perfect heat engine, absolute best efficiency possible in a perfect no-loss universe is 50% heat->motion conversion). Of course, my Sterling engine will run from the heat of the open air versus the 10C of 10 meters down in the ground; but a bigger temperature difference means better efficiency overall (improve efficiency: Colder cold side OR larger hot-cold difference). Their steam engine will do lower efficiencies at a much higher temperature difference (you need a condenser, i.e. a cold side for the steam to vent to).
The short of it comes out to jamming a Sterling engine's hot side into something hot, cold side into something cold. This could mean using the engine itself to mechanically (i.e. no heat -> lateral -> torque -> electricity -> torque lossy conversion, just direct heat -> lateral -> torque) drive a pump to have a heat exchanger convey heat to the hot side of the Sterling, and another to power a cooling system to drive 10C (from the water table, several meters into the ground) to the cold side.
Want more power? Create an alloy with high thermoconductivity (i.e. it gets friggin' hot when you apply heat, unlike the heat shield on the shuttle) and a very high melting point, and use that for the heat exchanger, transport tubing (wrapped in heat shield style insulation!), pump, and Sterling engine body. Jam that into something even hotter (can it go into magma without melting?). And you'll want a bigger Sterling engine; remember the engine itself is the cooling system for the working fluid!
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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.
Surely if the Earth's core is cooled too much due to excessive abstraction of geothermal energy, it will eventually solidify, shrink and start rattling around like an old walnut in its shell? And what if it bursts through? Come to think of it, even before that happens, there's a goodly-sized risk that the outer crust will be able to move independently with respect to the centre of mass, which will play merry havoc with the seasons.
Je fume. Tu fumes. Nous fûmes!
I'd say its a pretty crappy article.
_ heat;_ylt=AjvFzIDtqIn2aRl98jpXkE.s0NUE
The Ozzy company in question is Geodynamics and you can find their web site here: http://news.yahoo.com/s/ap//ap_on_sc/drilling_for
Their website has a good description of the progress and the problems they have encountered. I looked at investing in the company a few years back. So this isn't even current news.
The _real_ problems have not yet surfaced. There are two (2) major issues.
1) The amount of water one needs to push through the rocks tends to be rather large before one can obtain a significant amount of energy. At a 1 gigawatt level we are talking close to a river's worth. Of course 1 gigawatt is a lot of power and a 1 gigawatt plant of any sort would be expected to cost over a billion.
2) Fracing is a big problem. When you frac a formation the cracks tend to follow the weak spots and not go where you want them to go. So GDY.AX has a few holes down but this is still all experimental and there is nothing at this point that says when they pump down water that it will find its way to the well from which they want to pump the water up. In fact they may need to drill a few more wells to find where the water goes.
I certainly hope their venture is successful. However at this point I am declining to become an investor.
Any in Slashdot who wish to are certainly welcome. At least now you know the company and the trading symbol and the exchange. No thanks to the article of course!
Deleted
I clipped the correct one! Contents were from the worng page! Blame firefox. Blame me for not checking this before I posted the comment.
m l
Geodynamics website can be found here: http://www.geodynamics.com.au/IRM/content/home.ht
One needs to look closely at the projected economics.
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.
Bullshit!
A gigawatt power plant costs in the range of a billion regardless of the energy source. Does anyone think there is even the remotest of chances that geothermal can come in at 1/100th the cost of other energy sources and that no one would try to develop it? Why else would geothermal be experimental? Or are they suggesting that over 50 years a geothermal plant might produce as much power as 104 nuclear plants do in a year?
The most obvious conclusion is that comments like this are just stoopid and illustrate the ignorance of people.
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.
I've wondered many times why /. does not link directly to AP sourced articles. Why's Yahoo! getting tens of thousands of page hits on an article, generating all that revenue, for something they had no part in?
Submitters, please consider looking for alternative sources when linking AP, since you are really just giving money to the big empires you dislike so much.
I know, off-topic, but I think it's worth mentioning, unless you like just funneling hits to such abysmal, ugly, hellholes on the web like Yahoo when the same article has been linked on probably 10,000 other sites, most with good bandwidth, less intrusive advertisements, and a cleaner layout.
To explain gravitational heat, Marone again evokes the image of the hot, freshly formed Earth, which was not of a consistent density. In a gravitational sorting process called differentiation, the denser, heavier parts were drawn to the center, and the less dense areas were displaced outwards. The friction created by this process generated considerable heat, which, like the original heat, still has not fully dissipated.
Then there's latent heat, Marone says. This type arises from the core's expanding as the Earth cools from the inside out. Just as freezing water turns to ice, that liquid metal is turning solid--and adding volume in the process. "The inner core is becoming larger by about a centimeter every thousand years," Marone says. The heat released by this expansion is seeping into the mantle.
For all this, however, Marone says, the vast majority of the heat in Earth's interior--up to 90 percent--is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. These isotopes radiate heat as they shed excess energy and move toward stability. "The amount of heat caused by this radiation is almost the same as the total heat measured emanating from the Earth."
Sometime billions of years in the future, he predicts, the core and mantle could cool and solidify enough to meet the crust. If that happens, Earth will become a cold, dead planet like the moon.
Long before such an occurrence, however, the Sun will likely have evolved into a red-giant star, and grown large enough to engulf our fair planet. At that point, whatever heat is left in the mantle will hardly matter.
So there you go. It is cooling down very slowly so there is plenty of energy for us to use. Also if you know about the end of the universe, you will understand that eventually we will not have enough energy to survive anyway. http://en.wikipedia.org/wiki/Heat_death"All the other places the heat flow is too low to be usable for anything else than house heating."
Stirling engine?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Not that US nuclear plants add up to much of anything with regard to TOTAL US energy consumption. More Slashdot hyperbole.
"Probably they meant $800 billion to $1 trillion?"
0 8/01/analysis_says_war_could_cost_1_trillion/) then not only would we not be in a quagmire in Iraq, but we would no longer have to be so involved in the political process in the middle east? Imagine if the amount of money going to that region was halved. The political power of people who are not at all friendly to the West would be cut substantially.
So you're saying if we had just invested in Geothermal power instead of the war in Iraq (http://www.boston.com/news/nation/articles/2007/
If this is true, then it seems the only thing standing between the United States and energy independence is a will to do something about it. Maybe we need leadership (and I'm referring to much more than Bush & Co) willing to do something that will do a little bit more than just try to ensure a steady stream of oil from a politically unstable region.
You were mistaken. Which is odd, since memory shouldn't be a problem for you
Without these favourable conditions, you'd be drilling far deeper to get the required temperature differentals, which would require entirely new drilling tools and complicate the whole process.
Of course to some extent this heat can be "mined". The crust is a good heat insulator so it takes ages for the heat to escape the Earth. By drilling and pumping water, one can extract this heat quicker thus increasing the flux. But then, it's no longer a renewable source and it's not going to be virtually inexhaustible.Of course there are some "hotspots", where geothermal energy is viable but it will not solve the energy problems.
Save the bandwidth. Don't use sigs!
Every Coal, Nuke, Natural gas, and even Wind plant is made via a manufactuering line. It allows the costs to be dropped TO 50 or even 10% of the other costs. Not even GE power makes a geothermal line (though they will be happy to produce a VERY expensive one for you).
Geothermal plants are much cheaper to run than Nuke, Coal or gas plants. Once the upfront costs drop for them, then these will be put in places like the western USA where we could easily power the west and even midwest. But once these are started, then the tech research will turn to how to drill to the mantle cheaply. Colorado School of Mines has a laser drill that they are trying to make bigger and more efficient. Once it is scaled up, the idea is to drill very deep so that countries can obtain cheap energy (in addition to being used on mars and the moon).
I prefer the "u" in honour as it seems to be missing these days.
Did I actually read something like "800 million to 1 billion dollars invested in geothermal could supply a significant percentage of US energy needs by 2050"? I think that this number is off by a factor of 1000 at least. 800 to a billion dollars is less than what the US spends on the Iraq war in a week and is about what California spends in a month on cosmetics.
Another serious problem that no one is talking about is the actual cost of transforming the economy to sustainable energy resources. By the time that most people realize that it has to be done, Peak Oil will have set in and the resources for conversion might be difficult to find.
People are going to have to make some hard choices: hard by 2007 standards at least. Does your city build a new sports stadium for $100 million and get an NBA team or does it spend the same amount on a municipal geothermal plant that will keep electricity rates at their current levels for the next thirty years while every other place has theirs growing 8% a year? In the US in 2007 you aren't going to find many if any people in authority who will make the rational decisions in such choices.
So what's geothermal anyway? Dig a hole a few thousand feet, put in a pipe to the bottom and pump in water? Sounds like an oil well already. Do you have to put the generator also at thousands of feet below the surface? If not, do you have to thermally insulate the pipe so that the steam doesn't reconvert to water thousands of feet below the generator? It's not easy, dearest Slashdaughters, and you aren't going to get it working on a major scale for 800 million dollars. Because if you could, it would have already have been done. (A conditional subjunctive future perfect verbal phrase, for all you grammar affectionados).
That's enough to power 82 flux capacitors!
I have spoken'eth.
is the fact that the geothermal advocates look forward to 100 GW as their limit horizon, whereas we need 20 TW (== 20,000 GW) to meet demand in 2 decades' time.
... but just remember that solar has absolutely no equal. Not even remotely close.
Compare that to the 150,000 TW (== 150,000,000 gigawatts) of solar irradiation at the Earth's surface. and you can see just how "funny" (in the sense of inconsequential) 100 GW really is. And then to see the greater picture, just rise above the atmosphere to find some real power. With acreage no object, solar energy tends towards infinity.
By all means use geothermal sources as well as all other renewables
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra
The "native americans" had to get close to their prey to kill them. In getting close to a grizzly, or a bison, or even an elk or moose, they risked their own life. As such, many learned to make good use of what they had. "Causasian american" did run the bison off of cliffs. But it had NOTHING to do with getting any part of the animal. That was a simple extra. The idea back then was to deplete the main food source of the plains native Americans who were the ones giving us problems. As such, we ACTIVELY were wiping out the animals. Sad but true.
I prefer the "u" in honour as it seems to be missing these days.
Yellowstone as we are all aware is a super volcano. You can tap anywhere in there and bring up all sorts of heat. The real problem is that most developers want to do wet wells (use the steam from the water downbelow, rather than a dry well. The dry uses recycled carrier (typically water), but the advantage is that it will not reduce the water pressure from below. In addition, the idea of building a hydrogen plant HAS to be the worse idea going. For the costs of creating storing, moving, and running it in a ICE the hydrogen, you will put the overall efficieny at below 25%. Even if you use a fuel cell, the most you will get is 33%. OTH, if you create electricity there, ship it via wires, you currently lose 7%. Allow Storage to cost another 10% (it is not; normally, it is much lower). Now, you are in the low 80's, with the ability to increase it by focusing on superconductors and energy storage.
I prefer the "u" in honour as it seems to be missing these days.
Iceland has, for a long time, been exporting energy in the form of aluminum.
By 2050???
I hope I'll be in a flying car powered by a perpetual motion machine (think Moller meets Stroen).
Just kidding, by 2050 I want to be teleported to wherever I want to go!
When I have a kid, I want to put him in one of those strollers for twins and then run around the mall looking frantic.
So get to know the science, and be afraid. Be very afraid.
Yes, get to know the science, and be very afraid when you realize that you've taken falsehoods on trust and have believed them without justification.
600m years of temperature and CO2.
So, over 600 million years, where exactly do you see a correlation of CO2 vs temperature?
The simple answer is, you don't. Instead, you see that they are not correlated in the slightest.
There have been epocs in Earth's history with well over 10 times our current CO2 levels, yet the Earth was suffering the worst state of glaciation ever at the end of the Ordovician Period. The only correlation is within the last million years, a mere blink in geological time, and even that doesn't separate cause from effect -- as the well-know Keeling curve shows, changes in temperature cause dramatic changes in CO2 levels.
So, don't be a sheep. Look at the science for yourself, and stop believing those who hijack science for their own agendas.
The heat STILL flows upwards. In addition, we will obtain energy from elsewhere. Right now, we get it from coal, oil, natural gas, AND nukes (the same stuff that is heating our core AND our surface). Heck there are coal seams that are burning all over the world. If we got ALL of our energy from the earth, it have little to no impact on this planet. Why? because it will still flow upwards. The heat is generated via the nuclear degradation AND via the core spinning.
The idea of conserving is good, and there are lots of changes happening. LED lights will change our useage. Likewise, electric cars ARE coming. Even though W. and his oil companies are pushing hydrogen, the electric car will take over (right now, electrical storage is better and cheaper than hydrogen will be in 20 years from now).
I prefer the "u" in honour as it seems to be missing these days.
Don't be too dismissive of geothermal not being 'usable for anything else than house heating'. In a goodly chunk of the US, just replacing househeating means a significant drop in energy consumption. Here in the Puget Sound region I run my heater for all or part of eight of the twelve months of the year in an average year.
From TFA,
Also, rocks tapped by drilling would lose their heat after a few decades and new wells would have to be drilled elsewhere.
especially in combination with
Promoters of the technology say that while geothermal drilling is costly, it's cheaper to run once it's in place.
Whereas the summary, at least to me, implied sustainability with minimal infrastructural investment. Drilling thousands of expensive new 3 mile deep holes, risking earthquakes to the nearby area, every 20-30 years is not exactly the problem-free energy solution for the country/world that the summary implies.
The worst part is that TFA was written because of the bad things that were happening with the project in Switzerland, NOT to tout the viability of geo-thermal power, as the cherry-picking in the summary seems to.
Now that I think about it, I'm pretty sure everything I just said is completely wrong.
In the netherlands, a geothermal energy project involves the reuse of old coal mines.
http://www.mijnwaterproject.info/
In fact the only real answer is to find a source of sufficiently high grade (i.e. high temperature) waste heat, and use it as directly as possible. After all, that's how conventional power stations all work. You do not need an alloy with particularly good thermal conductivity, you need one with good hot strength. And you really do not want a Stirling engine. Conventional steam technology does the trick as soon as the high temperature region is sufficiently over 100C, and the seals have been under development successfully since the 18th Century. You can in theory make a not terribly efficient heat engine as soon as your heat source has a high enough temperature to get some pressure out of low boiling fluids like diethyl ether, but although it's amusing in a lab demo I suspect that reasons of cost, solubility in practical lubricants, and general health hazard make this a bad route to go down.
Pining for the fjords
Why does a relatively limitless energy source need to be economically feasible? Was the war in Iraq an economically feasible way to retain the rights to oil in the region? Wouldn't a relatively limitless source of energy, at any price, eventually spark an economic chain reaction? These are political problems, not technological.
Where is the Slashdot for politics... "News for the rich and powerfull"?
The Shell petrol station in Reykjavik already sells hydrogen. It's not clear who to exactly right now, but Shell obviously believes it has a future.
Yes, so then we all switch to hydrogen only to discover that water vapor is also a greenhouse gas and that the increase in local humidity from a million cars burning hydrogen becomes the new crisis. Heck, some parts of the desert Southwest have seen local microclimate changes from too many swimming pools humidifying the air. Sustainability is not a problem of technology, it's a problem of lifestyle. It's not that we burn carbon fuels, it's that billions of us burn carbon fuels and at ever-increasing rates. Billions of us burning hydrogen will just create other massive problems.
God (if s/he existed) forbid that we just scale our lives down a bit and walk or ride bike.
To say that geothermal power has no environmental effects is to ignore our recent attempts at utilizing it. In the 1980s, a flash geothermal plant at Beowawe in Nevada destroyed one of the largest geyser fields outside Yellowstone by lowering the water table and reducing the amount of heat available. The same thing happened at Steamboat Springs, Nevada. * http://www.elkorose.com/geysers.html * http://en.wikipedia.org/wiki/Beowawe,_Nevada The same thing happened in New Zealand when geothermal power plants were constructed there. * http://www.uweb.ucsb.edu/~glennon/geysers/world.ht m
There's also this list of geysers and other geothermal features that have been destroyed, in various ways, by man. Notice how many of them are due to geothermal drilling.
* http://www.wyojones.com/destroye.htm
I'm all for energy independence, and it may turn out that Geothermal has a role to play in it. But let's not delude ourselves into thinking that it has no effect on the environment.
"Think about how stupid the average person is, then realize that half of 'em are stupider than that!" - George Carlin.
"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
One would hope that it is far more digits than "a single person driving a car has nearly zero impact on the environment."
- RG>
Hey pal, this isn't a pleasantforest, so don't waste my time with pleasantries!
Not forever. Just until terrorists blow up the power plant
What about Iceland then? it's not spent any money on going into Iraq and nobody's blowing up their geothermal plants...
Because 15:1 the same environmentalist that oppose oil drilling because of the disturbance to the land would also scream about geothermal plants and their attendant power lines. After all many places will be "pristine nature" and as such require "protection". Even if its a great source of energy that is clean there will be groups that will oppose regardless of reason or potential improvement.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
Of course I did look up the Kalina cycle before my post, both technical descriptions of the process and descriptions of proposed projects.
Nobody is claiming this process is 100% efficient. They're talking about efficiencies in the range of 60%. In some cases proponents talk about efficiencies that are "80% higher". However since existing coal plants reach efficiencies of over 30%; adding 80% to that gives you 110%; so they must be talking about current efficiency *1.8, not current efficiency + 80%. That would yield efficiencies in the range of 55% to 65%, precisely what the proponents have been claiming when they talk in absolute terms.
It's misleading to say these things run off of "waste heat", as if "waste heat" is something different than "useful heat". Heat is heat; and while more efficient processes do capture some heat that would otherwise be wasted, but they never capture 100%. It's physically impossible.
If you actually look at a block diagram a Kalina cycle engine, you will see it has an element called a condenser. In it, cold water enters, and "cold" water exits. But if the water were perfectly "cool", why have a condenser at all? Or if it were needed to work some magic, why not feed the output of the condenser back into the input?
The answer is that the "cold water" exiting the condenser may be relatively cold compared to the liquid in the main loop, but it's still warmer than when it entered the condenser. If you fed the "cold water" output of the condenser back into the input, the system would stop functioning. The system won't function unless there is something to carry at least a bit of waste heat away.
Why? Simple. The turbine is not 100% efficient. The fluid in the primary loop is chosen to allow a very efficent turbine, but a 100% effient turbine would have fluid exiting at absolute zero. A realistic turbine will have fluid leaving at something above the ambient temperature. Keep running the fluid through the primary circuit, and eventually it becomes as hot as your heat source. Since you can't get heat to flow from hot to hotter, you can't extract any more energy. The temperature on both ends of the turbine is equalized, and it stops turning.
So, the whole shooting match requires enough heat to be extracted and thrown away to return the liquid in the primary loop to some base temperature that is cooler than your heat source. Maybe you can find some use for that waste heat, like heating an apartment block, but you can't utilize that heat within your engine itself.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
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.This seems to be just what Iceland has been doing al along...
;)
Lets just hope they don't have any accidents as they had in Iceland. Toying around with this enormous amount of energy can be very dangerous: during the drilling and testing for one of their power plants, they hit a spot that was just a bit too hot to handle, and the whole drill and pipe systems was found again several kilometers away... Let them be warned
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?
Human nature in the western culture, you mean. IIRC American Indians, many African cultures, and even our old agricultural society were much respectful of the environment.
The various waves of migrations into the Americas became dominant through genocide. Pre-European Americans were also responsible for numerous extinctions and ecological disasters. Africa and Asia are little different; there are numerous examples of genocide, slavery, infanticide, and man-made ecological disaster. The only groups of humans that managed to live "in harmony" with nature were those lacking the technology and population growth to have any impact.
Current myopic stance started with the industrial revolution, which i suspect was carried off by few powerful people.
Quite to the contrary: European enlightenment was the first time that a major human culture began to understand the responsibility and utility of taking care of their fellow men and the environment. Of course, that didn't abolish greed and intolerance overnight, but it's meant enormous and unprecedented progress over the last several centuries.
Umm... Well, nuclear power is about 20% of the electric supply. If you include all energy sources (planes, trains, and automobiles), it drop to about 5%. Still, a billion is nothing compared to the amount that any other electric source requires for that much output.
Have you been touched by his noodly appendage?
Calpine's "Geysers" geothermal power plant network in Lake County, California, are still online. http://www.geysers.com/ According to Wikipedia and Calpine's web page it is the largest geothermal network of power plants in the world (http://en.wikipedia.org/wiki/Calpine & http://en.wikipedia.org/wiki/The_Geysers). According to the same sources, it is currently producing 750MW and they are pumping about 11 million gallons of "treated wastewater" (read: sewage) from Santa Rosa PER DAY into a geothermal area and producing steam to spin turbines to generate electricity. I haven't read that they are losing output - where did you read that? If anything the output has been steadily increasing. It was 700MW a few years ago, and it has been rising. http://www.renewableenergyaccess.com/rea/news/stor y?id=48784
m and note the extremely high number that are situated around "The Geysers".
For all it's non-CO2 generating goodness, however, it definitely produces a LOT of earthquakes. We have a house near Pine Grove, CA, (near the Geysers) and throughout the day the earthquakes are so frequent that it's like living next to a major freeway. Look at this map of California and Nevada http://quake.usgs.gov/recenteqs/latest.htm and then note the massive number of squares just NNW of the SF Bay Area on the map - or look at this list: http://quake.usgs.gov/recenteqs/Quakes/quakes0.ht
Geothermal is a neat solution to producing power, but to say that it has "nearly zero impact on the climate or the environment" as the original article states is a bit misleading. It may have zero impact on the environment around the world, but it has profound (and frequent) impacts if you happen to live near the power plant stations. No matter what anyone says, you never quite get used to them - either. They wake you up at night, they rattle the dishes during dinner - some of them feel like the house just dropped a foot, some shake like a large truck crossing on a bridge.
What are the possible ramifications of releasing so much of the earth's core temperature into the atmosphere as steam?
Seismic? Climate?
once we have extracted all the heat!
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Except that the primary danger from oil tankers and pipelines is that they will rupture. No such risk of that with geothermal energy, but don't let an inconvenient truth get in the way of your environmentalist bashing.
Local geothermal use is much more efficient. Idea is that ground temperature is 60' F year round. In the winter you can exchange cool air to heat it, and in the summer you can exchange hot air to cool it. Usually a well or field of pipes is dug on the property and the water is pumped through the house to have the desired effect.
The *problem* is electric usage by the AC and burning natural gas, neither of which would be reduced by building a new power plant.
bash-2.04$
bash-2.04$yes "Don't you hate dialup connections?"| write USERNAME
They were doing this in Basel, but stopped because they were worried the earthquakes they were causing would affect the UEFA Euro 2008 Cup.
Oil wells in the U.S. are incredibly non-productive. People always think of oil wells as the geysers they see in movies and cartoons (or Kuwait during the first Gulf War). The reality in the U.S. is that two-thirds of them produce fewer than 5 barrels of oil a day
Because they aren't run to capacity. If wells in the U.S. really only produced an average of 5 barrels a day, the oil industry wouldn't bother to drill here. No, they just tap the most profitable wells first and leave the rest for later or only run them to fill contractual obligations. For example, I know some ranchers who signed deals to have at least X number of barrels pumped from their property. The oil company comes in, gets the X number of barrels, and then shuts off the well until the next time they come.
The problem with your conspiracy theory is that it involves a developing technology which the oil companies are perfectly suited to take advantage of (that was rude of you to selectively edit this out when you quoted me).
And you should have thought about where they financial interest lies. Why bother with geothermal energy, which needs development and has a much higher start up cost than an oil well, when oil has been obscenely profitable for them?
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.
Electric power will take care of the vast majority of our transportation needs: freight trains can run on electricity, and GM's 17 year old EV1 would have taken care of most commuting needs. No, electric power doesn't solve everything, but it could reduce our current oil consumption to a trickle.
A complex heat exchanging structure planted in the Earth deep enough could provide adequate steam to turn a turbine much like a nuclear reactor. Except the pressure vessel in this case would be the Earth itself. I'm not saying drill clear down to magma; but close. Harnessing the power that is beneath our feet is something we should have done and proliferated greatly a long time ago.
The game.
While the article (and most Geothermal articles) discuss using the heat from the earth to convert water to steam, or as a semi-passive heat-source for Winter-heating; why not connect a 'hot' water supply to a sterling engine and just use the temperature differential (where the geothermal-heat doesn't need to be deep/hot enough to convert water to steam) to generate electricity?
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
The summary is misleading, Geothermal power [wikipedia.org] plants already exist.
Yeap, Iceland gets a lot of it's energy from a geothermal source.
FalconShould there be a Law?
Here in Italy we've had geothermal power since 1904.
http://en.wikipedia.org/wiki/Larderello
And before it was used to move turbines in factories.
We are at the point where undergraduate students could come up with something better as a student project - the thing was not as good as everyone said it was and was horribly expensive due to what was available at the time and the expensive design choices made. Eventually spending money on a politically motivated project didn't look any good anymore - a different design (ie. mini-moke VS attempted rolls royce) would have changed this but wouldn't have had the PR impact the project had aimed for. Personally I think it's solving the wrong problem - mass transit is a far more energy efficient way to move a lot of people around and a small petrol driven motorbike is a better way to move one person around. If the problem is pollution (and this is a big one in China now so we may see some action) small electric cars make sense and shift the pollution to large plants where really simple pollution controls keep the NOx and SOx out of the air.
It's only racism when a white person says something bad about a minority individual or group.
No, it's racism when anyone anywhere uses some stereotype to cast anyone in a bad light.
FalconShould there be a Law?
The of the $1B a month being shipped of to Iraq right now. I wonder what $1B a month would do if it went into geothermal, wind, and solar panels domestically?
By the tyme the war in Iraq is over if the USA had instead used the money to fund an Apollo or Manhattan Project sized renewable energy source I bet the USA would be energy independent, well as independent as anyone could get. Natural resources like coltan would still have to be imported.
FalconShould there be a Law?
Does your city build a new sports stadium for $100 million and get an NBA team
Cities, government, should never pay to build sports stadiums. Every study I've ever heard conclude they cost more to build than any revenue generated by them. All government funded stadiums end up being is corporate welfare for those who own sports teams.
or does it spend the same amount on a municipal geothermal plant
I'd rather not have the government pay for this either, but between the two I'd rather the power plant be government funded. Let private enterprises pay for both. What government, local government, may pay for is the power lines delivering electricity from the power plant to the end user. But then allow open access to those lines and let anyone who wants to generate electricity to pay for and use them to deliver power to any end user that's willing to pay.
So what's geothermal anyway?
In geothermal generated electricity a liquid is pumped into underground pipes where the liquid is heated up before being pumped back up. A heat exchanger topside "pumps" out the heat which is then used to spin a turbine, usually by generating steam.
Dig a hole a few thousand feet, put in a pipe to the bottom and pump in water?
Pipes don't need to be that deep depending on where geothermal power is being generated. All it may take is 100 feet or less.
FalconShould there be a Law?
I have no interest in getting "mallrats wet", my own kids are older than your average "mallrat" so it's safe to say I don't see them in the same light as you do Mr. Boner. My age may also be the reason why I have no fucking idea what skull rings have to do with Pink Floyd?
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Yes. At Wairakei. So you are quite right. Geothermal power has been around for decades. The NZ plant illustrates a key problem. Geothermal power is a simple heat engine. Either you release an awful lot of steam into the atmosphere along with hydrogen sulphide, arsenic and other geological nasties, or you cool it and warm up a river. Wairakei in New Zealand pumps it into the Waikato River. It does try to alleviate the ecological back-lash by water re-injection. The ecological side effects are a major limit on the plant. (Or were when I visited 20 years ago. I'm out of date.)
They ought to harness the tremendous untapped power of the human posteriori gaseous emissions
35MW of capacity sitting about 20 miles from me as I type this.
:)
Plus we have wind farms, beaches, girls in bikinis, volcanoes, a bunch of top astronomical observatories, and other things geeks like. And that's just on my island.
Maybe the Perl Whirl cruise should come here again.
Village idiot in some extremely smart villages.
Googled a bit and found this with nice charts :) :e lectricity_productio.htm
http://www.geothermie.de/gte/gte28-29/geothermal_
I have to agree with plntrvlr. The effect that Geothermal tapping can have on the climate would be extremely miniscule. The rock you are pulling heat from, is in turn pulling heat from the rocks beneath it. If we don't concentrate where we pull the heat from, it would dissipate to the surface anyways.
Almost all the arguments made so far seem very invalid to me. It appears that few people are applying their arguments of detrimental effects against power extraction methods already in use. The major arguments against it that I have heard so far is that:
a) We might pull too much heat from under the surface and adversely effect the core.
b) Moving heat from under the core to above the core will effect some sort of environmental balance.
c) Earthquakes
As far as cooling or effecting the core of the Earth, that is lunacy. The core of the earth is ALOT hotter than the rocks we are pulling heat from. Cooling a rock the size of Candlestick Park by 200 degrees over the course of 50-75 years (unlikely)... The Earth is FAR bigger and FAR hotter. It would be less detrimental than hair falling out of your head.
In ragards to (b), yes. That's exactly what it does, and fortunately that's about all it does. Coal physically extracts resources from the Earth and emits CO and CO2 into the atmosphere along with that heat, and Nuclear power releases heat without pulling it form the Earth, and the by-products are in a league of their own as far as Environmental effect. Geothermal would have all the positive effects with far fewer negatives. Except one...
Earthquakes: If they are triggered, yeah... Life sucks. It's unlikely to damage the pipes, but will almost certainly spook local communities. The likelyhood of this occuring after the drilling has been completed seems pretty minimal, and a Scale 3 - 4 Earthquake will MAYBE put a 70+ unbalanced old woman with osteoperosis in the hospital.
All in all - weighing the pros and cons of this energy source shows that it would be the most effective with minimal real environmental impact.
But clearly you have something better to say...
Uhhh, has anyone done a study on what will happen when we start drawing the heat out of the planet by the tera-joule or what have you? I'm pretty sure that is NOT a renewable source. Anyone have thoughts / info?
"virtually inexhaustible"
I seem to recall them saying that about oil...then natural gas...and even now about coal.
It seems their optimism is "virtually inexhaustible".
-Styopa
The Future of Geothermal Energy Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Centuryl ogy.html
http://www1.eere.energy.gov/geothermal/egs_techno
This is a fun pdf to read if you are actually interested in this subject.
Mmmm....desertification
Now, where can I find 82.644 Deloreans?
What was once true, is no longer so
Why can't we bring the heat up, like a giant heat sink, instead of pump water down?
How much would need to be tapped to meet current demand? Seems pretty weird to choose such arbitrary numbers. So if we tap 1% then it would serve 1400x our current demand?
Go to Newfoundland? What? People still live there? Judging by the number of random people here that speak in that incomprehensible east-coast accent of yours I was convinced you'd all already moved to Alberta years ago...
Live and learn I guess.
But your argument rests on the hope that corporations will put long term energy over massive, short term profits. I wouldn't hold my breath if I were you.