Good news on geothermal energy

Geothermal energy is one of those alternative sources that always seems to be waiting in the wings. The basic idea is to exploit the heat (derived from radioactive decay) of granite rocks about 4k below the earth’s surface to superheat water which can then be used to drive a turbine at ground level. It’s a closed cycle so the water can be used over and over. Sounds good, but so have lots of other alternatives to carbon-based fuels that have so far failed to deliver on a large scale.

But now, it seems to be a lot closer The test run by Geodynamics produced 10MW of power and they are talking about a 250 MW plant, with orders already in place from Origin Energy. The Cooper Basin appears to have gigawatts of potential capacity, and large areas of the country are unexplored.

Of course, the big issue is cost. It’s hoped that power can be delivered at 4c/KwH, but it seems likely there will be some overruns. Nevertheless, if the cost of C02 emissions is taken into account, geothermal will very probably be a winner. Once again, it’s evident that, unless we ratify Kyoto now, we are in danger of missing the boat. Australia has a huge endowment of this resource, and a good start on the technology, but no doubt it can be found elsewhere and will be.

31 thoughts on “Good news on geothermal energy

  1. This sort of thing makes it even more criminal that our Coal Mining Government will not participate in the world efforts to reduce CO2 emissions. Australia has probably the richest endowment of renewable energy in the world and this geothermal power is but one example.

    Kyoto will not do anything to reducce emissions however it is important that so many countries agreed together to at least try. Australia played a leading role, to our eternal shame, in scuttling the Treaty. We were allowed to INCREASE CO2 emissions just to try and get us to sign.

    In 2012 the Kyoto Treaty runs out. It is at this time, if Australia does sign in 2008, that we can play a leading role in getting China and India into Kyoto II. If the US is still reluctant then it will be completely isolated. We have a fair bit of leverage with China as they use millions of tons of our iron ore and coal and gas to make the steel for their growth. Kyoto II can have real cuts and could make a difference.

    Our economy is incredibly sensitive to climate change which makes to folly of the Howard Government ever more culpible. This is what happens when we have a major drought http://stevegloor.typepad.com/sgloor/2005/05/a_reminder_of_h.html
    If global warming does indeed change our climate for the worse what will happen to the rural sector. The resultant climate change is totally unpredictable and if Howard and his cronies are betting on our climate getting better there is no surety that this will happen. You may as well pick a winner on a Saturday down at the track.

    Geothermal energy will be important as it is one nail in the coffin of coal for power and an strong argument against nuclear power in Australia.

  2. Geothermal energy seems very plausible and highly desirable to me, although you do have to make sure the figures stack up. Whilst not being an economist (as occasionally comments of mine on this site clearly show), it is hard to see why this wouldn’t be economic in the long-term once enough R&D is done to get everything right. Compared to coal and gas fired power, there is no cost for material to keep ‘feeding’ the power station and it is 24 hour baseload (as opposed to solar and wind). It’s hard to see why there would be significantly higher maintenance cost, and making the bore/s is the main extra construction cost.

    I wrote in a piece on my site about the small scale geothermal power station currently at Birdsville (which powered about half the town before being closed at the end of last year but is to be reopened soon). This goes to a shallower depth so the water is only just under boiling temperature, but the people behind that station told me that it only needed around 2-3 million dollars to build an upgraded one that would power the whole town, thus doing away with the 3 deliveries of diesel each month to power the local diesel generators – paying for itself soon enough, as well as having less noise, and zero emissions (as well as wider impact of having delivery trucks on the road, etc).

    What I found interesting in talking to some of the Mayors of these remote Shires is how knowledgeable they were about the technology. They spent more time talking with me about renewable energy generation than they did about cattle or Telstra (and not just cos they knew I’m a vegetarian). Some of them have clearly looked into the issue extensively from the point of view of large scale power generation, such as you’re writing about, as well as localised mini-plants for many of the communities out there which are not on the main power grid.

    The potential seems huge and the benefits obvious to me, but it is hard enough for them to get guaranteed investment in something like the Birdsville mini-station where the technology is basically already proven to work economically. Getting proper dollars developing big scale power stations still doesn’t seem to be possible, even though the dollars seem to be there to build more coal or gas fired stations in Queensland.

    The other obvious beneficiaries of this sort of technology would be Pacific Island nations, many of who have a geology that would enable similar super-heated water to be generated. This seems far better than noisy, polluting, non-renewable diesel generators which have to continually be replenished, including the hassle of regularly transporting the fuel.

  3. I don’t think you’ll get a word of disagreement on the merits of this project.

    However, one concern that does come to mind is the location of the geothermal resources. The really big resources in central Australia seem to be a hell of a long way from where the power is needed. How much is it going to cost to take that power to where it’s needed? Are the resources closer to the major capitals (the Murray, Perth, Hunter, and Otway basins) big enough to supply a significant amount of power for long enough, and are they going to be available for the same low price?

    Another concern is the location of the Otway basin. Isn’t that in the middle of a National Park? The plants themselves should be reasonably low-impact, but the necessary access roads and power lines aren’t…

    While I’m very excited about this, I don’t think we can rule out the nuclear option for Australia just yet. And, clearly, Australia is blessed with options for renewable energy that more densely populated countries don’t have.

  4. Ender, even leaving aside the high cost of the gear to produce hydrogen by electrolysis, you’ve got a bunch of issues. The statistics I’ve been able to dig up suggest that electrolysis is about 70% efficient. Then you’ve got to convert it back to energy, for which you’ve got two choices: fuel cells or turbines. Fuel cells are maybe about 60-70% efficient, a combined cycle turbine about 58% (though in both cases you can do better if you use the waste heat for hot water or building heating). You also need to throw in the capital cost of the gas turbine (which works out to be about 1c per kilowatt/hour, according to the estimates I’ve read) or fuel cell (much more expensive at the moment, always likely to be dearer than a turbine IMO).

    In any case, even if we’re generous and assume 70% efficiency on both ends, the total efficiency is only 49%. So, with the costs we’ve taken into account, that 4c/kwh power is up to at least 9 cents – and we haven’t even considered the cost of getting the hydrogen to where it’s needed.

  5. There’s a few questions the news item didn’t cover. Does the viability of the project require a tax break, a capital grant or soft loan, the government building the transmission line or an increase in the now stagnant renewables quota? Also a percentage of the water will be lost so it can’t be recycled. Will the loss be affordable? Will the cooling towers lose efficiency in surface heat waves? After long distance transmission losses the metropolitan sale price will have to be under 15c/kwh. It’s not easy being green.

  6. One aspect of this is not just how viable we can make it for Queensland’s power (oh, and everywhere else in Australia too), but can we be at the cutting edge in developing the technology for elsewhere.

    The long distance to transmit the electricity may impact on its viability (although I’d like to see more detail), but that should not be an issue for Pacific Island Countries. Also, using mini-stations along the Birdsville example would have to be even more viable for the same reason. These sorts of places may never get onto the main grid because of the costs of transmission over long distances to such small numbers of people, but that is all the more reason to develop more local generators to replace the reliance on diesel generators.

    However, I’d still be keen to see much more exploration of the possibilities for larger scale geothermal generators to plug into the main grid.

    And while I don’t support excessive subsidies for something that at its heart is not economic, there are other possible flow on ‘developmental’ factors which shouldn’t be totally discounted – not least could be tied to encouragement for greatement settlement in some inland areas. Coupled with proper telecommunications and transport infrastructure, it can be part of a worthwhile broader investment in slightly reducing the concentration of people on the coastal areas.

  7. I am prepared to bet $5 that the people talking about desalinization of water to supply Sydney not only have not considered renewable energy sources for desalinization, but would have difficulty explaining how either solar or geothermal actually work. Any takers?

  8. Just threw it in there as an idea. My pet project is to produce hydrogen from sunlight with the yet to be developed hydrogen cells and then convert it to methane.

    Anyway if the hot dry rocks are anywhere near a natural gas pipline the hydrogen can just be converted to natural gas and fed into it.

  9. Ender, that’s an interesting idea, methane being much easier to handle than pure hydrogen.

    Any figures on the cost of making methane from hydrogen?

  10. If the government was serious about an investment in renewable energy, and based its decisions on the kind of logic that even admits humans are affected by the state of the natural environment, we would have seen signifigant investment in researching and developing alternatives like geothermal.

    Instead we see government money poured into “clean coal” and ethanol.

    Government policy on renewable energy has very little to do with the environment, and until it does geothermal had better find a way to use masses of minerals or agricultural produce.

  11. Since the Cooper Basin area already has gas pipelines and not powerlines the hydrogen gas idea has a cost advantage, though efficiency calculations show it is better to send the electric current long distance and convert to H2 at the other end. However hydrogen can make steel pipe brittle. Methane is a hydrocarbon some 20 times more greenhouse unfriendly than CO2 which in any case is one of the combustion products of methane.

    I believe clean coal is a stalling tactic which probably won’t work. Ethanol has dodgy economics but that may be the new reality of the 21st century. As I said on a previous post if these squeaky clean technologies can’t fill the huge gap then nuclear looks inevitable.

  12. No figures yet. It really depends on if CO2 can be extracted from the air at a reasonable cost. No-one knows that yet. It is possible to do it with a small modified Solar Tower like Enviromission’s. The solar tower generates the flow of air and the CO2 is extracted with substances like quicklime.

    I wrote up my idea if you are intersted and it is at

    http://stevegloor.typepad.com/sgloor/2004/09/the_methane_eco.html

    The high temperature electrolysis method to produce hydrogen that is supposed to be used with new nuclear reactors can also be done with solar thermal as it can generate the required temperatures easily.

    Nuclear for Australia is not a given yet. We have abundant renewable resources – we just lack the political will to implement the changes necessary.

  13. Origin has contracted to buy the first 200 Megawatts of pwoer from a commercial plant so they seem reasonably confident about the economics.

    One use for power in the Cooper basin would be steam-reforming of natural gas. Basically, natural gas when it coems out of the ground is a mix of methane, carbon monixide and carbon dioxide. Mix the natural gas with steam and pass it over a catalyst and some of the carbon monoxide and carbon dioxide reacts with hydrogen from the steam to produce more methane. You boost the energy content of the natural gas and remove the need to vent the CO2 later, reducing total GHG emissions.

    CSIRO has already been conducting research doing this using soalr energy to produce the steam.

    It should be pointed out though that geothermal energy, in some locations at least, isn’t really a renewable power source. Over 20-30 years the rocks start to cool and the net energy available drops. This has alreayd happened at some sites in Europe.

    One possible use for “stranded” energy in places like central Australia would be to run compressor plants to liquify air. The carbon dioxide could be sequestered (or used for other purposes such as as a feedstock for synthesising plastics or liquid hydrocarbon fuels), the oxygen and nitrogen could be sold for industrial purposes.

  14. Actually, that hydrogen/carbon oxides thing is probably the simplest thing to go for, particularly if the emphasis is to get methanol or formaldehyde (which can easily be polymerised to give a conveniently handled solid). And you can always combine technologies; for instance, the simplest way of using solar energy is to cook water and low energy biofuels so as to get water gas (which means that the carbon involved is not part of a carbon addition to the environment).

  15. PM, true. Mind you can also use solar systems to boost conventional power in various simple ways. One of the central Queensland power stations runs its water intake through a trough solar reflector which heats it to something 50-60 degrees, reducing the amount of coal required.

  16. If you are interested in the “hydrogen economy” read Joseph Romm’s book “The hype about hydrogen” (2004). His main point is that there is no chance of there being a hydrogen economy before 2040. He notes that from a GHG perspective it is crazy to use electricity from a renewable source to make hydrogen, it is much better to use the electricity directly – every watt produced renewably replaces a watt produced from coal and so reduces GHG, but the inefficiencies of making hydrogen means that when you finally use the hydrogen to do something useful, you are replacing much less than one watt’s worth of GHG.
    Iceland is developing its geothermal resources and working towards a hydrogen economy – see ch 9 of Romm’s book

  17. John, please fix the units for the cost you mention.
    If 4c/Watt means 4c/Whr => AUD 40$/kWhr or roughly
    1/10 the cost of power from AA batteries.

    4c/kWhr puts it in the range of costs for nuclear power given in
    The lastest nuclear reactor technologies PDF 3Mb) which gives a range of 3-10c (AU) / kWhr and capital costs of between 1200-3100 AUD/kW.

    The Energetech Wave System mentioned on The National Interest claims, with caveats “Moderately good wave climates should produce power using first generation systems at a cost of around 10 cents US per kWh, and ideal sites at a cost around 5 cents. Over time, on moderately good sites, with capital cost savings from second generation designs, we can see the technology regularly delivering electricity at around 4 cents US kWh�.

    So ~6-12c AU/kWhr

    After the BBC Yellowstone Supervolcano drama, I wondered about nuclear power. The reference above, gives 5-6 yr construction times, the pebble-bed modular reactor is still at the pilot plant stage and the newer, safer advanced reactors are planned for the 2010-2050 timescale.
    So basically, unless you already have your nuclear plant up & running i you’d be out of luck in a Supervolcano winter. How well the Australian grid would cope with snow & ice would be an interesting question.

    Interesting suggestion by Ian Gould on “stranded” energy above.
    I’d guess that air liquefaction efficiencies would be better somewhere cooler, with less need for bulk transport.
    I’d guess that stranded power be applied to produce either something than can use existing pipeline infrastructure like the steam
    reforming, or something highly power intensive of high value, where
    transport costs for the product and infrastructure aren’t prohibitive.
    For something like experimental geothermal energy, you may also want something that can survive power interuptions.
    Guessing
    Isotopic separation?

  18. RDB, I have a much better report on the new near-term feasible plant designs and their projected costs. The AP-1000 looks like the best combination of “economically feasible” and “can be built soon”.

  19. In the Chemical & Engineering News Sep. 2004 referencing the same US DOE roadmap it says :-
    The Westinghouse AP1000 light-water reactor has also been submitted to NRC for full design certification. Westinghouse Electric, which is wholly owned by BNFL, built the first PWR in 1957.

    As such it is further along than the geothermal, wave power & PBMR
    which are still at pilot plant stages.

  20. Joe, if you look at my earlier comment there are two reasons for the interest:

    1) these geothermal plants may be located a very long way away from where the demand for power is.
    2) renewable energy isn’t available on demand.

    This gives two possible applications for hydrogen:

    1) as a transport medium to get the energy where we want it, for the geothermal plants.
    2) as a storage medium if we’re ever going to expand renewable energy beyond a small part of the grid (or, conversely, go big-time into nuclear power as a way of providing peak power).

    Whether either application will prove economically efficient is debatable.

  21. rdb – the Pebble Bed reactor is apparently fail safe and is the new standard for ‘safe’ nuclear reactors. The older designs are being phased out.

    Most claims about US nuclear power costs completely fail to include waste disposal cost. decommsioning costs and liability insurance costs which are all subsidised by the US government. Any new nuclear reactor built in Australia would not have the protection of the Price Anderson act as US reactors do. The subsidies required to build a working reactor in Australia would be far better spent on renewable resources.

  22. In theory, it should be possible to react C02 and methane to produce methanol or ethanol but I lack the chemical knowledge to know what the intermediate steps would be, what the energy input required would be and how practical it would be.

    Methanol or ethanol would be a lto easier to store and transport and could be substituted directly for petrol and deisel with minimal need for new infrastructure.

  23. Ian – given hydrogen from water and CO2 from the air a Reverse Water Gas Shift reaction will give a synthesis gas that can be converted with a catalyst to methanol. More complex reactions can yield a high cetane diesel fuel.

    Methanol is easy to store and transport however we successfully transport methane now so nothing really needs to be changed.

  24. The cheap method is to start with water and low grade bio feedstock and get a mixture of water gas and producer gas from it – nearly all nitrogen, hydrogen and carbon monoxide. Then clean that up and change the proportions to get the right mix of hydrogen and carbon monoxide to synthesise methanol (it’s an industrial scale process much like synthesising ammonia).

    The industrial scale would become practical around a geothermal site. It’s easier to get to methanol than to methane starting with those low grade gasses, which are all that the low grade biofuel will produce cheaply. Incidentally, cheap methanol (or at a pinch ethanol) is one of the ingredients for biodiesel.

    For what it’s worth, there is an industry that gets cattle cake protein supplements from a modified form of methanobacter. In the wild that lives of naturally occurring methane, but in the commercial process they find it cheaper and safer to use methanol.

  25. Last time I was in the Cooper Basin it was desert with not a lot of biomass to process. It is usual in not only petro refining but in biomass conversion to use some intermediate output as a fuel, bagasse in the case of sugar and black liquor in the case of paper pulp mills. The woodchips to diesel process backed by Volkswagon and Daimler-Chrysler uses I think 10% of its output as fuel. They don’t need another energy source. The problem with sites for hot rocks is the same as sites for geosequestration in that they are few and far between and usually not where the supporting activity has developed. This is why very few proposals for renewables are likely to succeed as long as fossil fuel remains cheap.

  26. Yes, I know that area is desert. The point I was making was more general, but looks closer at this one. It would only need a small transmission line to reach areas where low grade stocks were available. The ones you cited are higher grade; just about anything that could be harvested renewably with little input (capital, labour etc.) would do. Stuff you wouldn’t normally consider an agricultural product. Few deserts are completely lacking in something, somewhere.

    And, of course, the necessary somewheres night still be within the geothermal zone.

  27. At the risk of banging on long after everyonelse has lost interest, it jsut occurred to me that there’s one quite energy hungry bit of infrastructure that runs right through the Cooper Basin – the Adelaide to Darwin rail line.

    I wonder if electrifying that would be worthwhile?

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