Geothermal is getting warmer
It’s been some time coming, but the Australian geothermal industry has finally got some good news it can call its own.
The aspiring geothermal energy company Petratherm, after experiencing months of delays caused by unseasonal rains, has just completed fracture stimulation tests that indicate its resource in the north of South Australia is deeper, wider and hotter than it previously thought.
Over the past two years, that is a conclusion that could rarely be reached by the small band of geothermal explorers that have managed to secure the funds to drill wells. Results have delivered either a lack of heat or a lack of porosity, or in the case of Geodynamics, a nasty reaction with the chemicals lying deep beneath the surface. It forced the anticipated timetable for the rollout of geothermal energy - seen by many as potentially the most effective replacement for fossil fuels - to be set back, and questions to be raised if it could ever fill its expected role.
For Petratherm and its partners Beach Energy and TRUenergy, however, the fracture stimulation test undertaken by the US giant Halliburton over the past week at the Paralana 2 well, have been overwhelmingly positive.
The testing, which involves injecting millions of litres down a well at high pressure, setting off thousands of "micro-earthquakes", indicated micro-fracturing occurred as far as 900 metres to the east of the well – far beyond the 500m hoped for – and at depth of 3,500m to 4,000m. And it found considerable heat, from 176C at 3,750m to estimates of 190C at 4,000m.
“We’re very excited about this,” said Petratherm CEO Terry Kallis. “We’ve got the best of all three worlds – width, depth and heat. Now we have to have a look at the data and consider the best way of proceeding.”
What makes Petratherm’s resource particularly interesting is that it features both natural fractures and the ability to create man-made ones. That in effect gives it a choice between regarding it as a more conventional geothermal resource where companies can simply exploit the natural flows and pressure to extract the heat, or to use artificial means such as stimulation. It may do both.
“It’s between two ends of the spectrum,” Kallis says. “We have got natural fractures that exist at the right depth, and we know its over-pressured, so we’d expect flow.” This gives Petratherm the possibility of being able to have three production wells rather than two for every injector well – effectively an increase in productivity and a lowering of costs. Kallis says it represents a potentially significant de-risking of the project.
The next step is to consider the data and decide on the placement of the Paralana 3 production well, to be drilled later this year. When that is completed, along with circulation tests next year, then a 3.75MW pilot plant could be installed by the end of 2012 – a critical stepping stone before a planned 30MW plant that it hopes could supply energy to the nearby Beverley uranium mine, and potentially the giant Olympic Dam project nearly.
Petratherm has been allocated a $63 million grant from the Federal Government to develop the demonstration plant, although it has yet to access those funds and will not until its circulation test is completed. It has previously estimated that a geothermal plant built at scale could deliver emissions-free baseload power to Olympic Dam for less than $100/MWh - considerably cheaper than many alternatives.
The other major project is the 25MW demonstration plant planned by Geodynamics at Innamincka, for which it has been allocated a grant of $90 million, although delays caused by a blowout at its well nearly two years ago means that it has only accessed $1 million of those funds. It hopes to have a 1MW pilot plant in place in 2012 at Innamincka.
The plans of other geothermal aspirants have been put on hold because of an inability to access funds. The federal government is still reviewing what to do with $35 million of drilling grants that were made but not accessed because the recipients could not obtain matching funding, effectively bringing drilling programs to a halt.
“This is a significant result for the company and for the industry,” Kallis says. “What we hope it does it that gets a few people back on board, we see that as the real opportunity here. The industry has been in need of good news and we are happy to be part of that.”
Comments on this article
Stranded at the Grid
At first glance to any engineer with steam cycle experience, I would agree that 176°C with a reinjection temperature of 95 appears to be pretty hopeless. However I just finished a consulting project for a large developer that had a resource significantly worse than this and to my surprise the numbers did stack up. I can see that Petratherm would be ecstatic with a 176 resource.
As I see it the biggest problem for the geothermal companies is proving that their wells will produce for 30 years. These are very deep wells and 30 years is a long time!
Time to accept facts and change tack
Response to Trevor Ridgway
It's really astounding that the powers that be, devote so much energy on such an exercise in futility.
Peabody Energy, sensing a soaring global coal super cycle demand, has flagged further coal acquisitions in Australia. No wonder ex Labor NSW premier Morris Iemma said the carbon tax scheme will have a limited environmental impact, while coming at a significant cost to the economy.
We better make it work!
The Treasury report on the carbon price has hot rock geothermal producing 21% of our electricity by 2050 if we are to avoid more than 2 deg C of warming. That means about 100 TWh/yr - about half our current total. We need around 15 GW of geothermal by then to product that.
Keep up the good work lads!
Geothermal is getting warmer !
Aaaahhh ! Giles , the eternal optomist................& good on you..............never let the facts spoil a 'good-news-story' !
I was reading about the "IBM Pollyanna Principle " : this infers that in an ideal world .....machines will do all the work & people (freed from having to work ) will do all the thinking. ..........Conversely , the world seems to be filled with machines that don't work & people that don't think !
In New Zealand or Iceland where geothermal activity is at the surface the extraction process is simple , reliable & straightforward. It is , unfortunately , a dangerous environment in which to live !
Thank goodness , I live here in geologically stable Australia. Pity about the problem extracting geothermal power anywhere near civilisation though ! 'On the surface' it seems such a good idea ! ( I guess that is why we were provided with abundant coal , gas & oil supplies , just to keep the "playing-field level "perhaps !!??)
Confusion reigns supreme
It's interesting to note that the Federal Government allocated $63 million to help develop a Geothermal energy source to supply uranium mines.
yay
Thanks Giles, great article and detail.
Test Plant at $4million a mega watt! Say What!!!
It's going to take a lot of scaling to get down to $100 a mega watt.
Bit like saying Italy takes the lead with a hot salt solar solution at $12 million a megawatt! They can keep the lead.
At these prices we are looking at really cheap coal replacements of $4billion to $12billion for 1000 megawatts.
Forget about the hot air or "crap" as JG calls it .. we need some serious economic reality of replacement costs for coal or gas at remote locations.
Keep in mind the Greens/Environmentalists were part of the group that saw a 1000 megawatt "clean gas solution" at Newport turned into a 500 megawatt peak load clean gas solution ... for environmental reasons! And this was right on the suburban grid with virtually no transmission loss! Over 20 plus years how much extra "nasties" did that result in being produced at Hazelwood.
Geodynamics' project is stranded from grid
As well as all their other problems, Geodynamics have known right from the beginning that their project is stranded far from the grid, requiring billions to be spent building a grid connector. Not surprisingly they want the Government to build it, and not surprisingly the Government isn't in a rush to do so. See
http://www.peakoil.org.au/news/index.php?geodynamics.htm
Petratherm's 176°C (at source - less at the surface) is pathetic as a heat source, given that a re-injection temperature of 95°C means there is only a 81° margin available for power extraction, which has to include the power to run the pumps.
Geothermal
I really can't see large quantities of electricity being generated from a 190 degree C source. We need thousands not tens of megawatts if it is ever possible to replace coal or nuclear.
I'l believe it when I see it
Well, let's see if they can drill all that rock without breaking anything...
Fracking
Geoff,
Let's make a distinction between fracking of deep granites (as is the case with Petratherm and Geodynamics) and fracking of shallower sedimentary formations as is done for shale gas or coal seam gas. My understanding is that where Geodynamics and Petratherm extract their heat, and perform hydraulic fracturing, is well below the aquifers, and the contaminaton potential that you are referring to is very low or non existent.
Geothermal progress
Geothermal is potentially a great energy source, but is subject to the risks of fracking, including contamination of aquifers. Given that we are just beginning to take some serious steps, it is an ideal time to address the environmental standards that should accompany the industry. And hopefully step around the issues raised by gas extraction.
Fracking can lead to the mixing of aquifers - say salt into fresh water or release unwanted minerals into an adjacent aquifers. In the US (and maybe here too) fracking medium can comprise of a cocktail of chemicals to enhance the results. These chemicals add to the contamination potential of the fracking process, and should be subject to apporval before being used.
In operations, the return heated water loop will disolve contaminents, and effectively concentrate those contaminents relative to their naturally occuring ratio's - in addition to fracking chemicals. Thus even very small amounts of mercury, lead or uranium can become concentrated in the water in significant amounts. Again cross-contamination is a possibility, or if the residues are captured at the surface, there can be difficult disposal problems.
I'm all for geothermal, but want it to be done safely.