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The Potential of Geothermal Power
Posted by
Zonk
on Sun Aug 05, 2007 04:34 AM
from the much-better-than-burning-goo dept.
from the much-better-than-burning-goo dept.
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."
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Floating Wind Turbines 194 comments
The Great Pulgoso sends us word that Norwegian energy group Norsk Hydro has signed an agreement with Siemens to develop floating wind turbines. The companies agreed on a schedule that would see a prototype in the North Sea by 2009 and a working wind farm using 5-megawatt generators by 2013. (Norsk Hydro unveiled the design in 2005.) Inhabitat.com has taken the giant illustrations from the Norsk Hydro site and reproduced them at a reasonable size. The design features a steel tube 200 meters long. It extends 80 meters above the sea surface and has three 60-meter blades. The whole thing is anchored to the sea floor by three tethers. The developers expect to be able to install the turbines in waters up to 700 meters deep.
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Misleading (Score:5, Informative)
Re: (Score:2)
The article mentions that in fact. I think they meant the first geothermal plant using deliberately injected water as opposed to heated water/steam that occurs naturally.
Re:Misleading (Score:4, Interesting)
It includes injection, but the key part is drilling into hot parts of the earth's crust, fracturing the rock, then injecting water into the fractured rock and harvesting the steam.
Both the summary and TFA are a little misleading. HDR is being tested in many parts of the world, including Japan, France, Australia and the US. The Australian site is here; http://www.geodynamics.com.au/IRM/content/home.htm l [geodynamics.com.au].
It's a promising approach to clean power generation, but it won't work everywhere. HDR relies on a steeper than normal thermal gradient. Temperature rises with depth at a rate of about 20c/km on average, so hole depths without the steep gradient are too great for power generation to be economically feasible.
Parent
Re: (Score:3, Interesting)
Re: (Score:3, Insightful)
Perhaps, but;
- The Geodynamics project is in the middle of a desert in South Australia. The nearest river is hundreds of kilometres away.
- That heat is energy. The HDR system uses that energy to turn turbines, and recycles the water back down the bore. There is no excess.
Excess heat is as relevant to a HDR generator as CO emissions are to an electric motor.Re: (Score:2, Insightful)
Re:Misleading (Score:5, Informative)
Parent
Re:Misleading (Score:5, Informative)
We use hot water pumped directly from shallow wells for the hot tap water. It contains sulfur.
It's close to 100C, so you can use a heat transformer to warm up the non-sulfuric cold water for showers, etc. Some houses here do.
Parent
Re: (Score:3, Interesting)
All capitalism really does is reflect popular sentiment through a kind of voting system.
Consider:
Many years back I was speaking with a coworker of mine about Green Mountain Energy, here in California. The price was essentially the same as local power, although occasionally more expensive. I had switched to Green Mountain. My coworker said that she'd looked into it, and that it wasn't worth the price.
The catch? I knew my coworker to be what
Re: (Score:3, Insightful)
As a side note, i also think we've been trained to think that the possibilities are communism, fascism, or the status quo (which is not capitalism and with no real free market, both being result of what the banking and insu
Re:Misleading (Score:5, Insightful)
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
Parent
Re:Misleading (Score:5, Informative)
Wow, that's so misinformed I can only laugh. Do you have any idea on how many goats that would take?
Sahara, for example, was born 4000 years ago because of a climate change. Land use by man was not an important factor in the creation of the Sahara. http://news.bbc.co.uk/1/hi/sci/tech/390097.stm [bbc.co.uk]
Parent
Re: (Score:3, Informative)
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
Quoted for irony, because horses were native to North America, until the ancestors of the original Americans ate them all.
PS: The pueblo Indians managed to deforest their environment to the point that their culture collapsed.
PPS: Also there is no such thing as 'American Indian Culture'. The American continents (like Europe) were diverse places with extremely diverse cultures. Positive racial stereotypes are still racial stereotypes, m'kay?
Re:Misleading (Score:5, Insightful)
-jcr
Parent
Not Worth It (Score:3, Funny)
Global Warming? (Score:3, Funny)
Re: (Score:2, Insightful)
Only if they increase the natural flow (Score:2)
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I suppose it depends on how deep you want to dig.
Remember "The Core"? (Score:5, Informative)
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.
Parent
Re: (Score:3, Insightful)
Then again, at that point we'd be using about 139PW. (That is, petawatts.) The earth's surface would be just about the melting temp
Re: (Score:2)
Would geothermal plants cause environmental problems if huge numbers were built? Almost definitely. Probably the best way to reduce overall impact from any one type of power plant is to always a mix of all the different types (solar, wind, tidal, geothermal, etc)--at least that way if one kind causes damage that we don't yet understand, the damage is more limited than if we used that method for 100% of our power generation.
Re:Global Warming? (Score:5, Interesting)
I recently visited Iceland where they use the country's ample supply of superheated steam to produce electricity (and provide hot water and heating). A related question that sprang to mind was "if the rest of the world did this, what would be the effects of letting all that heat out? Would the amount of heat that we would cause to escape from the planet's core be significant? We need a geophysicist to give a proper answer to that - but I'm a suspicious bugger and all this "free" electricity looks too good to be true - you know what they say about free lunches. Essentially, we'd be using the planet like a battery: it's just a question of how long it will last - millions of years? Thousands?
One of the other things that struck me about what the Icelanders are doing, is that they may just have struck their country's equivalent of oil. In the past, they couldn't really export their natural resource - steam goes off quite quickly. Then, they figured out how to make electricity with it, which is a bit easier to store and transport, but not out of the country. Now though, it looks like there may soon be a large world market for hydrogen, if fuel cells and other hydrogen consuming automotive engines take off. Iceland has all the ingredients to produce it - seawater, and abundant electricity. There are a number of problems to overcome in transporting it safely, but I reckon these guys may soon be rolling in it.
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.
Parent
The first one? (Score:2, Informative)
100 / 1.21 (Score:4, Funny)
Huh? (Score:4, Informative)
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 [wikipedia.org]...
Re: (Score:2, Funny)
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...
If they really want to see something interesting, they should descend into the crater of Sneffels [wikipedia.org] which the shadow of Scartaris touches before the calends of July. I have done this.
Arne
Re: (Score:2)
Re:Huh? (Score:5, Funny)
Why go to Iceland, or New Zealand when you can go to Newfoundland and get pissed instead? Who needs to worry about electricity anyway, Alberta will take care of us.
Parent
Bullshit! (Score:5, Funny)
article (or quote) must be wrong (Score:3, Insightful)
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?
Re:article (or quote) must be wrong (Score:4, Insightful)
Kind Regards
Parent
Re:article (or quote) must be wrong (Score:4, Informative)
Why would they correct something that they didn't get wrong? Just because a few slashdotters don't feel that the number cited is correct, you're going to tell them that they're wrong? How about doing three minutes of research to find out for yourself first? Let's hear it for "Citizen Journalism", where truthiness is more important than facts.
And for those of you playing at home, the relevent passage from the MIT study (press release here) [mit.edu] (actual study here) [inel.gov] [PDF warning] is this:
Based on growing markets in the United States for clean, base-load capacity, 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.
Parent
Just 40% They say.. (Score:5, Informative)
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.
Re: (Score:3, Interesting)
heat from the thermal vents on the sea floor, no drilling.
http://en.wikipedia.org/wiki/Hydrothermal_vent [wikipedia.org]
Would it be easy, no probably not,
Would it be easier and cheaper than drilling every ten years a new hole, most likely.
Re: (Score:3, Insightful)
-jcr
Re: (Score:3, Insightful)
and some of them are played out, ie. dry wells.
They might make good exploratory candidates as the first 16,000+ feet is
already drilled on a lot of dry holes.
Some are deeper: ( over 4 miles down )
Deepest well ( in california )(dry hole):
Total depth: 24,426 feet (Point of Rocks)
Year drilled: 1987
County: Kern (Sec. 29, T.30S., R.23E.)
Operator: Occidental of Elk Hills, Inc.
Well name: 934-29R
Ick, measurements (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.
No impact (Score:2)
Not Zero, not even close. (Score:2, Troll)
Apparently, scientists don't realize that the construction and maintenance of power plants and power transmission infrastructure has an environmental impact.
Re: (Score:3, Interesting)
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 environmen
Not quite the same.... (Score:2, Informative)
It uses the natural geothermal activity local to the region.
The numbers (Score:5, Interesting)
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
Re: (Score:3, Informative)
Oil wells in the U.S. are incredibly non-productive. People always think of oil wells as the geysers t
Re: (Score:3, Insightful)
There are several things you're missing in this analysis. First, the technology is not fully there yet - that's what the MIT panel said would take $1 billion and 10-15 years to develop. Second, any given reservoir of oil has a set, fairly short, lifespan. The geo-thermal source has an effectively infinite lif
The problem with oil company conspiracy theories (Score:4, Interesting)
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.Parent
Goethermal Reduces CO2 (Score:3, Insightful)
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 question of scale (Score:5, Insightful)
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.
Re: (Score:3, Informative)
Re: (Score:3, Insightful)
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.