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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."
No. It's not dangerous and it's not new technology. I know firsthand that it is used in California and the Sierra Madres of Mexico. Most of the homes in Klameth Falls, Oregon are heated via geothermal energy. I'm sure it's used in a lot of other places, so I'm a little surprised this is even news. I've not heard of any sort of accident or danger, other than the possible release of poisionous hydrogen sulfide gas, and that only during the exploration stage.
There are issues, but nothin insurmountable.
"Eve of Destruction", it's not just for old hippies anymore...
geothermal shouldn't steal a noticeable amount of heat- remember, the Earth is VERY big and VERY hot. I'd still prefer it if we went Nuclear. and that smart ass with the Adelaide crack... guess where I'm writing this from?
Kids! Bringing about Armageddon can be dangerous. Do not attempt it in your home!
After Iceland that is. I would think they are the world leader. They way they're going they'll be able to banish fossil fuels. Well, I suppose fishing boats and aeroplanes might be an exception.
And it's been studied extensively since the 1970s. this article has a nice summary of the research to date.
Will it effect the ground in any way?
Not really, no. We're talking about big solid lumps of granite, which at the sort of temperatures they're at to start with won't undergo any significant thermal contraction even if cooled to atmospheric temperature. Plus we're only able to extract a relatively small proportion of the overall amount of heat in these deposits, so the overall temperature of the rock won't change a whole lot.
PG&E has been generating electricity from geothermal energy for decades. See http://www.unocal.com/geopower/evolution/
This isn't quite the same kind of power generation. A few people have made similar comments about NZ and the US.
From TFA: "While the United States, the Philippines, Iceland, New Zealand and Japan already produce commercial volumes of geothermal electricity, their system uses naturally occurring steam from underground reservoirs and springs, rather than the renewable dry rock technology the Australians are developing."
Yeah, i guess aussie scientists arent all that bright when it comes it all as the only counting they usually get up to is the process of stacking beer cans and measuring womens cup sizes.
And i agree with you about aussie sheeps being scrawny and small compared to the new zealend sheep, i mean heck in nz sheep are considered sexual icons, sort of like brad pitt in the united states, so as a result they are very well looked after, groomed and are usually sitting on the higher income bracket.
At least they're nice and honest and admit that it's a non-renewable resource. They talk about an estimated reserve of at least 50 years and their depletion rate. They also don't use the word 'sustainable' that many people attach to geothermal energy.
The only thing I would like in addition is what is the production in GW*h/year? They mention peak of 1.1GW, but that implies just a 1.1GW turbine. My guess is that the geothermal energy is easily throttled, so they run it as a peaking plant to get the most bang for their calorie and that it doesn't make nearly as much GW*h/year as a 1.1GW coal or nuclear facility.
Environmental impact should be minimal, and there's hardly any ecosystem there to affect anyway. This region was chosen for the Woomera rocket range for exactly this reason. Australia's about 90% of the area of the continental USA, and much of it looks exactly like this area; arid or semi-arid rocky plains.
There's a transcript of an article with quite some depth (ahem.) here. http://www.abc.net.au/rn/science/ockham/stories/s1 440622.htm
It's news because they are talking large scale power generation, not individual homes or even towns indoor heating.
NZ has a different area of expertise. NZ has naturally occuring hot water springs. Tapping those is relatively easy. That's why NZ has had geothermal energy for so long. Iceland was in a similar fortunate position and they also have geothermal.
Australia is drier than Oscar Wilde's wit. There are no naturally occuring hot water springs. The technology being researched in Australia is Hot Dry Rock. The rocks are dry and you pump fluids down into the rocks. The water is forced through naturally occuring horizontal fissures in the rocks and collected by a second bore. This only works when there are insulating rocks above, below and around the fissures. Otherwise the fluid disperses and you never collect back enough water to make the system economical.
When it does work it's brilliant. The system powers itself and the only significant issue is dealing with scale buildup on the pipes. The energy output is enormous and the capital investment is modest. A single plant can power a small city with almost no pollution and no (as yet known) environmental impact.
HDR Geothermal works by passing water through hot, fractured granite. The granite is hot because of the radioactive decay of trace elements in the granite (too low in concentration for any radioactive waste concerns). A thick layer of sediment above the granite effectively creates a heat blanket, allowing the temperature to build to 200-300 hundred degrees C - ideal for heating water without building up extreme pressure.
I'm not a geologist, but I imagine that problems with pipe scaling would be much lower for HDR geothermal than in regular geothermal power, where you've got a lot of salts, sulphur and all sorts of muddy crap bubbling through. The water in HDR geothermal is kept in a closed loop so there's no waste to dispose of. The heat is extracted via a heat exchanger which boils a more volatile fluid such as ammonia and this fluid is used for the power generation. So you've got no impurities going through your generation facility.
Geodynamics say they have enough heat to power Australia at current levels of consumption for 70 years. Unlike solar or wind, the power is constant and can be ramped up or down at will. I'm surprised this has been off everyone's radar for so long.
One of these days I'm moving to Theory - everything works there
This isn't your gradfather's geothermal (assuming, of course, that your gradfather came from Iceland or New Zealand or any of these other countries built on top of active volcanos...) This is smack dab in the middle of a tectonic plate, geologically stable enough to be considered for burying nuclear waste (preferable encased in Synroc), and a _bloody_ long way from the nearest sulfurous vent. This is using heat from radioactive materials in solid rock, not steam from magma bubbling just below the surface. They'd have to pump the water in, because there's bugger all of it out there! (OK, there's the Great Artesian Basin, but this area is isolated from that by a few kilometres of impermeable rock. Which is why the whole scheme is possible in the first place.)
You're thinking of Western Australia. :p I'm still not convinced Perth actually exists. I mean, sure, it's on the maps, but when was the last time you ever heard anything about Perth on the news, or met anybody from Perth, or had Perth's existence validated in any other way?
...
Ok, I'll bite. As a card carring born again sand groper I think I have to validate my own existance.
Yes, Perth exists. Deal with it. Its (in my opinion) the best city in Australia, as far as actually being a place to live.
Whilst I know (as I was born in Melboune and went to high school in Sydney) that Western Australia was almost not on the map then, its getting hard to ignore now. It has the strongest economy in the country, just about the lowest unemployment (actually, Canberra is lower due to the large amount of government money there), and a city that has a future that doesn't depend on motor cars or even fossil fuels, so we aren't going to waste the economic benefits of having a strong economy.
Anyway, I'm sure I'm over reacting to a humourous statement, but I just had to
Michael
There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
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.
Slashdot: Where nerds gather to pool their ignorance
I was just in a small, community bank in the U.S. that installed geothermal HVAC when they rebuilt a decade ago.
They recouped the cost in five years and are very, very happy with the system. It heats for almost no expense in the winter (sometimes they have to fire up the natural gas furnace when it gets way below freezing) and cools for nothing in the summer.
It's also been basically maintenance free. Nothing on the order of what some of the naysayers here would have you believe.
I've also seen several rest stops in the area that use geothermal wells to cool and heat very effectively and efficiently. Near-zero maintenance is a very important thing for rest stops.
From what I've seen, geothermal is underutilized and underhyped and should be investigated closely by anyone doing new construction.
obviously no deficiencies vs. no obvious deficiencies
Some perspectives:
Concentrated hydrochloric acid is natural: your stomach makes some every minute. Uranium is natural: it's dug out of the ground like coal (also natural). Horrific, destroy-all-in-its-path wildfires covering thousands of square km. are natural and have been happening since long before humans came along. Just because it's "natural" doesn't mean it's nice.
Geothermal hot spots will be cooled, not eventually, but *immediately*. By a few degrees within centimeters of the tap, millidegrees further out. Meanwhile more energy flows in from elsewhere. Moderate extraction will simply set a new equilibrium point somewhat lower than the old one but will still provide plenty of energy, and energy flow into the affected area actually increases a bit since the potential difference has increased.
Meanwhile, yes, Australia should indeed develop its solar and wind resources *too*. Some companies invest in one, some in another, and society reaps the benefits of all of them.
Remember that the extracted heat *itself* can be looked upon as a pollutant, and by extracting it we're increasing the rate of pollution and moving another equilibrium point. One of the (possibly still distant) restraints on growth of a high-tech society is simply the ability to get rid of waste heat without moving an equilibrium point that's too touchy for comfort. And one of the laws of thermodynamics boils down to the principle that all energy eventually becomes waste heat, so the overall density of energy use should be considered carefully.