John M.

There really are only two options for cheap carbon free reliable base load power generation systems: geothermal and nuclear.

Geothermal power is a relatively simple process with few unknowns in the production sequence. Drilling wells is much the same as in the oil industry and that technology can be readily transferred. If we have a steam pipe at ground level then what follows is largely the same as the clean end of coal fired generation; we have heat exchangers, steam turbines and generators. Very clean. All this has been well understood for more than a century and the expertise required is not that great.

The GELs of Geodynamics in the Cooper Basin have the vast potential for generating power in excess of 10 000 MW. Large areas adjacent to those (held by other companies) are also very prospective. Australia's total production capacity is about 45 000 MW. It becomes clear that the Cooper Basin on its own can supply a significant fraction of Australia's energy needs. Building geothermal power stations is highly modular and can be done in steps of 50 to 100 MW or even larger if a government established goal and time frame should demand it. However it would require a will to do so.

The 1 MW plant of Geodynamics is not really a goal in itself, just a public relations exercise. Politicians and media will be impressed. The 25 MW plant is the first small real plant and is designed to influence the conservative utilities industry and thereafter the serious funding instrumentalities so that the 500 WM steps can then follow. After the initial positive commercial demonstration the speed of bringing additional wells on line can increase dramatically 'merely' by having a fleet of rigs systematically drilling hundreds of wells non stop.

There is no great risk. The engineered geothermal systems (EGS) still need some development but the unknowns can be controlled. We could even follow the very low risk conventional geothermal (HSA) line that Panax Geothermal are taking if we are feeling really insecure.

Hot rocks are reasonably plentiful the world over. Developing countries will need energy and geothermal is relatively simple. After establishment they could provide their own expertise. Dare I say it? .... They won't need nuclear physicists!

Limen

And thank you Limen. I guess the two responses that I have received to my post have explained the subject very adequately indeed.

However I still would like someone to answer the possibility of geological instability from widespread use of the technology.

Any takers?

Steve M.  (Just adding to David H's comments.)

The radioactive disintegrations in the granite occur at a very slow rate with heat as a byproduct. It takes many millions of years for the granite to become hotter than the surrounds because of the 4000 m insulating blanket of other rock above it. Because it is relatively close to the surface we desire to extract this energy by simple means without pollution and with tiny footprint.

The radiogenic heat occurs throughout the rock mass and the byproducts stay where they are. At the interfaces the only daughter product that could move is the radon gas. It has a half life of about 3.8 days so that after one month (8 half lives) the activity has reduced to 0.4% (1/256). It becomes harmless. There can be no build up of activity. Radon is inert so that it does not normally chemically combine with anything. After the initial circulation the amount of radon release from the granite surface is tiny. What happens to the radon? It stays in the closed fluid circulating loop. It never sees the light of day. Does this fluid become dangerous over time? No, it becomes less radioactive over time as just described. I would be prepared to drink the fluid if it didn't taste so bad (salty like freeflowing bore water).

Just to add perspective, if you live in a brick house you have a much higher exposure to radioactivity since radon molecules exude quite naturally from the wall by the same reactions. We live in this gas every day for most of our lives and nobody seems concerned! It is of course a miniscule effect.

Limen

Thank you David Hamilton for your response. Although I notice that an Annex for NORM has not been prepared as yet for Geothermal extraction.

Limen, I agree with what you say.  It is consistent with my earlier comment,

If you think there are likely to be large advances, you need to be able to point to a plausible line of development,

The comment was directed to Steve Derbyshire whose response to Peter Lang seems to be that 'progress is inevitable', based on an invalid analogy with quite different disciplines.

It will be fascinating to see how things unfold at Jolokia.  There are a lot of problems to solve.  A good overview of the technical challenges of HFR, particularly pertaining to the materials problems I alluded to, is at

http://depletedcranium.com/geothermal-power-generation-potential-and-lim...

Even if successful, where does this sit in the climate change response portfolio?  Next step is drilling for a 1 MW pilot plant.  Then a 25 MW commercial demonstration plant sometime after 2015.  The development of resources that may be of the order of a hundred or so MW.  If everything goes swimmingly we might have hundreds of MW available in 2020.  But if we have not yet built a 1 MW pilot plant, this is not a technology that energy system architects have available to design with for a decade, minimum.

The problem is, we need to be making deep cuts to our emissions in that timeframe, and these developments don't get us there, even discounting the possibility of failure in an enormously complex and technically challenging endeavour.  Steve and Limen both mention the nuclear option.  Should we choose to do so we could write a check for turnkey gigawatt scale clean power from a commercial vendor.  I do not understand why we would choose the long term, high risk, never been done option over the guaranteed and scheduleable option.

Steve, I don't understand what your youtube link is apropos of.

It is possible that some Naturally Occurring Radioactive Radioactive Materials (NORM) will come up with the water. NORM is a common occurrence in the oil and gas industry, and there are defined safety procedures (see, for example, http://www.arpansa.gov.au/Publications/codes/rps15.cfm ).

The amount of NORM coming up with the water will depend on the chemistry of the water, which the operator will be able to influence. NORM could be an issue for geothermal power, but should not be a major one, and certainly not a show-stopper.

I wonder what the widespread use of this technology (assuming that it's successful) will have on the geological stability of the area.

After all you will be pumping vast quantities of cool water on to extremely hot rock. Also isn't the basalt hot because of radio activity; will the return super heated water be radioactive?

Limen,

Two important points:

1.  We don't need so-called "renewables",  We have nuclear with an virtually unlimited energy availability.  It can be cheap, where the society doesn't do everything in theri power to block it.  It is by far the 'greenest' of all energy sources if we look at it rationally.  It is about the safest of all electricity generation technologies and has by far the least environmental foot print (for all the reasons I laid out in an earlier post).

2.  You are missing the point about the fracture aperture.  Rock fractures are not two planar surfaces like two panes of glass with an even gap between.  That is what would be needed to get the water to flow evenly over the surfaces of the fractures so it can extract the heat at the x W/m2 that is theoretically achievable.  But rock fractures in the rockmass are not like that.  They are complicated and intersect to form effectively channels through the rockmass so that water finds the easiest path or few paths and flows through those instead of flowing over the idealistic planar surfaces that the models assume for their analyses.  This paper explains better than I can:  

http://geoheat.oit.edu/bulletin/bull22-4/art4.pdf

Sorry Peter & John, I wasn't aware of your previous posts on this website, particularly "Italy's Solar lead"

I understand now - http://www.youtube.com/watch?v=kQFKtI6gn9Y

John M. Technological advances may well be not guaranteed but they are still very likely to happen. Necessity is still the mother of invention. In almost any system there are sufficient variables that can be 'arranged' to give some degree of the desired control. It may require some brainstorming and adapting of technologies from other fields but bright minds, given the freedom, can do great things.

If we are talking of the thermodynamic properties of bulk materials then, yes, those aspects are dead simple to understand and hence we can do our sums easily and see that the geothermal energy available is colossal. We don't seek to alter those properties. The next step is a process of technique. We think of fluid transport, we think of the oil industry who have been there before a million times. Ah, ...yes, it gets just a little bit difficult because the granites at the bottom are a lot harder and drill bits seem not to like it much. Perhaps a little R&D is required on this front. Perhaps Potter's spallation drilling may come to the rescue (too new). There are many possibilities.

Peter. Fraccing natural rock microfractures does appear to work. The upper and lower surfaces do separate and a consequent small lateral movement prevents the two surfaces from reconnecting. The gap is therefore permanent. Yes, there will be point and small area contacts where no fluid flow can occur but it does just flow around such obstacles. On a small scale the heat simply conducts to the adjacent regions where fluid flow does occur. What if the flows are insufficient? Then you do some more hydraulic pressurising at a higher value to increase the gap size. You can still do this 10, 20, 30 years later if necessary. You can also shoot propants into the gaps to keep them open if needed. What if the rock cools over time? You extend the same drill holes by another 1000m or so and repeat the whole process. It really is a wonderful project.

I hope you can see that there are no shortage of practical ideas that are known to work and other ideas that have great potential. However it does take time and money to establish the procedures. Coal fired power stations and nuclear ones didn't just suddenly appear. They also were researched and at colossal public expense. A minute fraction of that would would put geothermal energy generation on the map of history and solve many societies' problems.

Limen

Steve, the idea that because remarkable advances have occurred in in technology, genetics and medicine have occurred, we should therefore expect similar advances in utility scale energy technologies, is common, but without basis.  It is cargo cult thinking.

The examples of these advances you offer derive from sciences based on achieving ever greater structuring of the very small, and ever greater structuring of non-physical information.  But what we are talking about here are the mechanical properties of bulk materials and the thermodynamic properties of bulk materials, which are disconnected from the dynamic driving advances in the information sciences, microstructural engineering and medicine.  These rapid advances have happened looking down in scale, not up, where bulk material properties remain the same as they ever were, and their behaviours depressingly predictable.

There is no flaw in Peter's argument, at least for this reason.  If you think there are likely to be large advances, you need to be able to point to a plausible line of development.  Arguing by analogy to these very different scientific and engineering endeavours is not valid.

Peter,

While you make some good points, I find there is a major flaw in your argument (a flaw that seems to be repeating in this forum).  The flaw is,

You state;

“The problem is making fractures with equal aperture over the whole fracture surface and maintaining that for 30 years.  It is not possible.” 

The statement “It is not possible” is pretty intractable.  Geodynamics has done a good job of overcoming numerous obstacles over several years and while you may be correct, I find this defeatist attitude also unrealistic.  Most people are aware of the huge advances in technology, genetics, medicine, and most other aspects of our lives.  The success of HFR may or may not be as important as some of these other areas (only the future will tell). 

I am sure in the not too distant past, those mapping the humane genome or those (Australians), creating the technological basis for wireless internet, would have had similar detractors.  The difference between success and failure is not giving up. 

If HFR succeeds, Australia has a chance to create a world class industry in the renewable energy sector instead of continuing our status as a world class quarry.  Let’s not continue the mistake of educating our scientists only for them to commercialise the technology in another country.

Graeme,

You say: 

“If "succeeded" means that an EGS project has achieved commercial success, then the statement is false—this was achieved at Landau in Germany in November 2007.”

You have a different meaning of “commercial” than I do.  To me, commercial means the technology produces electricity at a competitive cost without subsidies.  I would call EGS hydrothermal generating systems commercial when they are selected and built without subsidies.  The plants you refer to are clearly small RD&D plants.  By the way, if you read the link I attached to my comment you will see that the US plant, the first, has been producing electricity since the 1980’s (from memory), but it is a miniscule amount and earns next to no income.  That does not make it commercially viable.  It is an RD&D facility.

You say:
“What Geodynamics is doing is the natural progression of a small number of largely sequential research projects around the world since the 1970's.”

I agree with this statement.  It confirms that6 EGS is in the early stages of RD&D, and has been for 40 years.  There are decades to run before EGS could become a substantial source of electricity generation, if ever. 

What Geodynamics is doing should be continued and encouraged.  What I am against is the continuous stream of wishful thinking about the likely timeline until we can have large amounts of baseload electricity from any of the proposed renewable energy solutions.   Meanwhile, no one wants to talk about the elephant in the room, nuclear.  If cutting CO2 emissions is the real issue, surely we should be seriously looking at what we can do to bring nuclear to Australia with a low cost structure rather than a high cost structure.  If nuclear is avoided on ClimateSpectator, it suggests there is a renewable energy advocacy agenda rather than a rational look at what we need to do to cut CO2 emissions.

"No country has succeeded with HDR or HFR yet after nearly 40 years of research, development and demonstration." The truth of this statement depends on your definition of "succeeded". If "succeeded" means that water has been circulated through hydraulically fractured rocks and returned to the surface carrying heat, then the statement is false—this was achieved in the 1970's at Los Alamos in the USA. If "succeeded" means that heat extracted from an EGS project has been used to generate electricity, then the statement is false—this was achieved at Soultz sous Foret in France in June 2008. If "succeeded" means that an EGS project has achieved commercial success, then the statement is false—this was achieved at Landau in Germany in November 2007. If "succeeded" means that an EGS has run for 30 years, then the statement is true. What Geodynamics is doing is the natural progression of a small number of largely sequential research projects around the world since the 1970's. To suggest that EGS is a failure because long-term (decadal) circulation has not yet been demonstrated is absurd.

Why are there so many sceptics out there?  Every piece of innovation reported seems to elicit a great deal of criticism by obviously, intelligent people.  Then again, I suppose many of the other smart people, not responding to these articles, are too busy working on the innovations and don't have time to contribute to these forums. 

After reading the numerous negative comments I am becoming convinced we should give up on new technology and stick with our 'perfect' current achievements - but something tells me this may also be a flawed path.

Geotherma hot dry rock (HDR) and hot fractured rock (HFR) is quite different to geothermal in volcanic areas.  Australia does not have volcanic sites like Iceland, Italy, USA, New Zealand and many Pacific rim countries.  So we are trying to make HDR and HFR work. 

No country has succeeded with HDR or HFR yet after nearly 40 years of research, development and demonstration.  The problem is not creating cracks in the rock.  The problem is making fractures with equal appeture over the whole fracture surface and maintaining that for 30 years.  It is not possible.  The water finds the easiest path between the injection and production boreholes, instead of flowing over all the fracture surfaces.  So the water runs in 'channels'.  So it cannot extract heat from the whole fracture surface.  So altough there is plenty of heat in the rocks, it is diffuse, like sun light and cannot be easily extracted.  There is an analogy with solar energy.  The sun has plenty of energy, it is the collection of it that is the problem.  The same is true with HDR and HFR geothermal.

http://geoheat.oit.edu/bulletin/bull22-4/art4.pdf

I want to see geothermal work as much as anyone.  But @Steve Derbyshire, whatever the reasons for it, the fact remains that nuclear is proven low-carbon technology at commercial scale, while (as this article demonstrates) geothermal is not, and (even if this test is a success) is at least many years from being so.

@Limen Wrinkle "multiple fractures that have to be generated to pass sufficient circulation fluid to make the energy transfer to the surface a commercial success"

Yes, that's what I meant by "volume-pervasive".

The hydraulic fracturing scheduled for Jol-1 has been done previously at the Hab-1 and Hab-3 wells, of course, at similar temperatures and pressures. If it is successful on the Jol-1 well it will indicate that the geological structure of the area extends over tens of kilometres. However that is already rather well known from the 4000 petroleum wells in the area. It is always good to get confirmation particularly regarding the granite basement which is the actual source of the radiogenic heat. The fracturing can't very well fail any more than when you squeeze a lump of putty it must ooze out from between your fingers somewhere. Water is wonderfully incompressible and it will find a micro crack somewhere to lift up the Earth if enough pressure is applied.

The critical test that is hardly discussed is the multiple fractures that have to be generated to pass sufficient circulation fluid to make the energy transfer to the surface a commercial success. This means producing a series of parallel sheet fractures spaced preferably at equal intervals and of equal gap width at the bottom of the 5000m well. That will be the real crowning achievement for commercial viability.

Limen

Hopefully the time horizon for defining 'success' of the testing will be better than that of the nuclear industry in its infancy - difference being the nuclear machine had access to multiple scientists and mega bucks over decades. Perhaps priorities were different during this stage of our history.

Now this is a really good, sharp piece of reportage and analysis.

However, even if the hydro-fracking works initially, we're not home and hosed yet.  Those fractures have to be both volume-pervasive and stay open for up to several decades if this technology is to live up to the billing.  As such, I'd love to know the time horizon for defining 'success' of the testing.

...