The Potential of Geothermal Power 397
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."
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.
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:Global Warming? (Score:2, Interesting)
The amount of cooling of the crust would equate (minus inefficiencies) to electricity produced.
This electricity would be converted to other forms of energy (and ultimately, more heat, I suspect).
Total overall energy in closed system would therefore remain constant, and thermodynamic laws are satisifed.
OK?
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.
Re:Misleading (Score:3, Interesting)
Re:Just 40% They say.. (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:Not Zero, not even close. (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 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/ [portsmouthabbey.org]
Picture: http://www.ebecri.org/custom/wind.turbine.html [ebecri.org]
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?
Re:Misleading (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 I call an "environazi". I.e., she was one of those types always going on and on about obscure environmental issues, like the vernal tide pool thingy and the evilness of the local walmart.
It would appear that where it counted, I was more of an environmentalist than she was.
Amusing.
Anyway, this sort of thing is typical.
C//
Hot Rock vs. Water Table (Score:2, Interesting)
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
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.