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Australia Pushes Geothermal Energy
_martini_ writes writes to tell us Reuters is reporting that several Australian firms are experimenting with taking geothermal energy mainstream. Geodynamics Ltd. will be making an investment decision on their first geothermal power station in early 2006. From the article: "Mother Nature has been kind to us. Australia could be the world leader within the next couple of years given the geological anomalies present in South Australia," says Peter Reid, chief executive of another explorer, Petratherm Ltd."
There are several problems that geothermal energy will have to overcome before it can be used for any large-scale power production. First of all, geothermal solutions are terribly corrosive and the pipes are subject to scaling. The maintenance costs associated with keeping the plumbing working are high.
These are just a few of the problems associated with geothermal energy: the variable nature of the reservoirs and fluids; the depth, location, orientation, number and type of wells; the type and size of power plant; the method of disposal of the spent geothermal fluid and the need to conform with local environmental regulations.
"Rocky Rococo, at your cervix!"
I was reading on a link from LRC about Nature's Nuclear Reactor, so the timing of this /. post comes just as I was thinking about the potential energy inside the ground.
I've ran the numbers for solar cells and windmill generators and can't see the overall savings. Taking into account the manufacturing, installation and maintenance costs, are these techniques better for the environment or any cheaper?
Geothermal seems like it would work well, if you can store the energy or throttle back the generation during lulls in need. The setup costs seem huge and I wonder how often they'll tap out a given dig's heat (if ever).
I think money will be better spent in more efficient storage of energy. Batteries, salts and event heat tanks all interest me. I'm not seeing any long term viability of anything but coal, gasoline and natural gas until the storage exceeds the unit per dollar ratio of the 3 gases mentioned.
.... given the geological anomalies present in South Australia
You mean the city of Adelaide?
READY.
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So if we use this to power Australia like they suggest, what are the consequences. That would mean stealing a lot of heat from the Earth that is trapped in these geothermal "deposits" (since it sounds like they found concentrated areas of heat higher up than usual). If we cool those down (which is what will happen when we extract heat from them) then what will happen? Will it effect the ground in any way? I'm thinking of towns where they used to mine salt or coal or something and the ground later started to collapse because the stuff was gone. While they are not removing rock, would removing the heat cause problems later? For example: remove the heat -> things cool down -> rocks contract from cooling -> empty space -> fissues?
Anyone know? I realize this would probably be a long-term problem (not something that would show up for a long time). Would this not be a problem because the ground could slowly adjust as we removed the heat, or would the heat stay high until the last minute then plummet (sorta like batteries do) causing problems?
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
I'm sure we can lend them some expertise — NZ's first geothermal plant was commissioned in the '50s...
(apparently, we get 18% of our primary energy from geothermal sources)
Repton.
They say that only an experienced wizard can do the tengu shuffle.
Not for generating electricity, but geothermal energy is increasingly popular way to heat residential buildings here.
It's already half cheaper than oil burner heating and as the oil prices climb, geothermal becomes more and more attractive option.
There are no atheists when recovering from tape backup.
This is just another attempt at Mother Nature to monopolize the energy market. First coal, then oil, now renewable engeries???
We must rise up to defeat this threat. Say NO to Mother Nature.
Unfortunately, the Earth is a great insulator. Heat from the mantle travels exceeding slowly to the surface. The maximum sustainable power density is many orders (at least three, probably more) of magnitude less than solar power. The unsustainable (deplete once) energy reserve is exceedingly dilute compared to fossil fuels. I haven't had time to do some hard math, but my gut feeling is that drawing out 8GW of heat energy will cool off a lot of rock real fast. (assupmtions are 15% rankine cycle and 12.5% net efficiency and a 1GW plant). How many cubic kilometers of rock can their collection system honestly cover?
Iceland has a much larger (though still finite) sustainable energy density, since it sits on the mid-oceanic rift, so it would be a far better site for a geothermal plant, though I have my doubts that 1GW could be extracted even from that island.
"I wish that they would do more around the yellowstone area" NO... leave yellowstone alone. And while your there, please catch and release.
"Truth is much too complicated to allow anything but approximations"
I just visited Iceland a couple months back, and I have to say that it made me wonder why geothemal isn't more popular.
My favorite iceland moment: I went to the blue lagoon, which is a spa next to a geothermal powerplant. Basically you've got this cloudy blue mineral water in a huge black volcanic rock basin, at one end you've got the spa, where you get in, and the water is probably just over 80 degrees. Then on the other end of the basin you've got geothermal runoff water boiling in. You can get as close as you like to the inlet, but when you get within 30 feet or so you're nearly getting cooked. There's also some silica mud and waterfalls along the sides. The view is dramatic with the industrial steamstacks on one end, a classy spa structure on the other, and the natural volcanic pool in the middle. Highly recommended.
But the point is: you're bathing in powerplant runoff. And it's supposed to be good for you. Now that's pretty amazing: I want that kind of powerplant in my back yard. And looking up in Wikipedia, the largest geothermal installation in the world is actually in California. And it doesn't put out some wussy windmill sized power, we're talking 2000 Megawatts -- that's nuclear plant territory, if I understand correctly.
Reykjavik is reputedly the least polluted city in Europe, and most of the heating and power is provided by geothermal -- they just run hot pipes through the houses. Iceland has some pretty unique geographic properties that lend itself well to the process, but it's hard to believe that this can't be harnessed elsewhere to good effect. I mean, I understand the startup costs are very high. And I understand the technology needs work. But we're talking about a nearly limitless source of energy that is clean, safe, and politically sound. It seems like a pretty wise investment.
Cheers.
Australia does not have any major fault lines, no volcanoes and has some of the oldest (most stable) bedrock on the planet. The heat in the Granite is not from magma, it is from the low level radioactivity in the rock itself. A big enough chunk of granite will get hot all by itself. Check out the CSIRO, they have been working on this kind of "geothermal" for at least 10yrs. Their numbers say that one site with two deep wells (500m apart) would remain hot enough to replace the largest power plant in NSW for 50yrs. Intrestingly the site they got those numbers from was just a few miles from said power station.
The biggest problem in Oz is that coal is not only sprinkled everwhere so as to convieniently fuel our current power stations, it is also a major export. These two things combine to make the coal industry fat, lazy and influential.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
I am studying at the ANU dept of Earth and Marine Sciences that is doing a lot of the research in this. This is not hydrothermal. You are right, there are no active margins and no active hotspots. This is using 3-4km deep drill holes, injecting plentiful artesian water down, fracturing the rock at depth and the heated water returning. The anomaly is a large intrusion that is near enough to the surface to make the project feasible. Sorry I haven't the paper at hand. Look at Geodynamics or look for papers by Prame Chopra. The "limited life" they are projecting is 300 years.
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