Outback geothermal plant goes live Geodynamics has pulled the big Acme switch on its Habanero pilot plant, near the remote South Australian town of Innamincka. Perched atop 4 km of drillings, the pilot plant has 1 MWe (megawatts of electrical energy) capacity and is about to enter a 100-day trial and demonstration project to be completed in August 2013. The …
"The company believes the Habanero site has around nearly 60,000 petajoules of recoverable thermal energy which would, it says, deliver around 7,000 petajoules of end user power"
So it is only a little better than 10% efficient, way less than current PV efficiency. Is this wasting too much natural resource?
Geothermal plants can be more efficient than this, but total energy conversion efficiency is not usual the primary aim, as the energy comes for free once the plant is built. Hence things like total cost of plant (and whether there is multi-stage turbines/heat exchangers factor in to it - i.e it might be cheaper per kWh to get 10% of the total resource energy rather than extract more and get 15%.
Haven't read up about this particular plant, but suspect most of the energy not turned into end-user power, will be reinjected into the ground to keep the plant running for a long period of time and to avoid having to dispose of geothermal fluid after it is used to drive the turbines.
Oh, and I suspect PV cells are not that efficient either if you are comparing total recoverable energy in an area to 'end-user power'. Geothermal is a great way of providing base-line power overnight. Would be interesting to see a mixed plant though - i.e. boost geothermal fluid temperatures using a solar furnace during the day.
Also, there will be a certain amount of loss in transmission - Innamincka is quite a long way from anywhere (about 1,000 km from Adelaide).
It's also somewhat misleading to compare the average efficiency of a geothermal plant with the peak efficiency of solar (which will only be delivered when the wind is in the right direction and the panel is pointed directly at the back of T. Abbot's budgie smugglers).
Then Satan all the demons will catch cold and move up here into the sunlight, in an effort to stay warm.
However, if they rise and go to the sun, where it is very warm, we risk demonic orgies and devil breeding, until the face of the sun is covered in evil spirits, and the light shall go out, casting the earth into darkness for all eternity.
So on the principle of scientific fact based faith, I call for the closure of the pathway to hell and prayers for redemption - and tax free income for the first $100 million for my church.'
'
About to become an issue again, thanks to the forthcoming giant monsters vs giant robots flick, Pacific Rim
Sure, it's right there in the article: they estimate the amount of extractable end-user energy to be 7000 petajoules. Translation: after having extracted that much, the rocks will have cooled too much to be of any use. Now how much is that? At 1 MW (1 million Joules per second), this will take about 200.000 years. I guess the plant won't last that long, however.
Re: "The rocks driving the geothermal plant have a temperature of about 242°C."
The pant will not last that long anyhow without serious maintenance. The LP turbines get a serious kicking chemistry wise and need replacing with alarming regularity otherwise they tend to pretty much dissolve. The mass steam flow is relatively low, hence the very small 1MWe output, but as the heat source is free, the economics kind of work so long as the drillings stay open long enough to keep the flow of water/steam going long enough to justify the initial capital expense (they tend to fur-up, a bit like your kettle at home).
Seismically active areas are better suited for geo-thermal plants due to the depth of holes required, re. New Zealand, California etc. Australia is not that active as far as I know. Good on 'em though for giving it a bash.
Since 2002, the Geodynamics Annual Reports have spoken of the construction of demonstration power plants as being the key to completing Stage One of their plan.
In 2009, a major blow-out occurred at one of their drill sites, engulfing it in steam. Fortunately, no-one was injured. At the time, Geodynamics claimed the blow-out would delay the commissioning of the demonstration power plant by 6 to 9 months. In other words, it would be up and running by about the beginning of 2010. (!!!!!!)
That 1MW plant was supposed to have been a 20MW plant
In the meantime, the Rudd Government awarded them $90 million, the largest grant ever awarded to a renewable energy project in Australia. Despite the fact that Geodynamics has not yet generated a single watt of energy, it has now been given $100 million of taxpayers’ money.
From its 2007 Annual Report "... working towards a 50 MW commercial demonstration plant expected to be operating by the end of 2011. It is then planned to expand this in nominally 50 MW modules to 500 MW by 2015."
For Kyza ... It will generate electricity sufficient to power around 1,000 homes, and more than enough to meet Geodynamics’ site needs.
Well, im happy to see some of my tax money go on it. Someones gotta do it first, and most tech improves as its developed and tested. Im also happy to see australia developing such tech. Lets hope its proven successful and keep an eye out for the next generation. Solar is good and getting better but as said above large scale geothermal runs at night. I also wouldnt worry about cooling the rock down. Our planet has a core of molten rock, theres a lot of heat down there.
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