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Earth Power Science Technology

Iceland Seeking 'Supercritical Steam' For Power Source (bbc.com) 160

New submitter FatdogHaiku writes: Already getting over 25% of its electrical power from geothermal sources, Iceland hopes to break new ground using "supercritical steam" from a 5 km deep borehole. Is it just me, or does this sound like the start of a movie where everything that can go wrong does in fact go wrong? It's not like they are new to the tech, but working with geologic sources at 450C to ~600C is a new ball game for anyone. It should be noted that Iceland also uses direct geothermal for most of its space heating. "In this area at Reykjanes, we typically drill to 2km or 3km depth to harness the steam, to run power plants and produce clean, renewable electricity," explained Asgeir Margeirsson, CEO of the Iceland Deep Drilling Project (IDDP). "We want to see if the resources go deeper than that." The "supercritical steam" holds more energy than a liquid or a gas. The team wants to bring it up to the surface to convert into electricity, as they believe it could produce up to 10 times as much energy as the steam from conventional geothermal wells.
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Iceland Seeking 'Supercritical Steam' For Power Source

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  • Why deal with the middle man?

  • anyone know.. (Score:4, Interesting)

    by drewsup ( 990717 ) on Thursday December 15, 2016 @08:10AM (#53489203)

    what kind of pipe they use for this kinda thing, im thinking some kind of ceramic metal hybrid?? Temps and sulfer corrosion must be a major PITA to deal with.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      PVC schedule 40

    • Re:anyone know.. (Score:5, Informative)

      by Mashiki ( 184564 ) <[moc.liamg] [ta] [ikihsam]> on Thursday December 15, 2016 @09:16AM (#53489509) Homepage

      what kind of pipe they use for this kinda thing, im thinking some kind of ceramic metal hybrid??

      A few articles I've found on it, state it's 6-layered titanium. Makes sense when you think about it, since titanium has a very high rating against corrosion, buildup resistance against materials on the surface and inside of it and very high resistances to temperatures depending on the "mix" that's used when the tubing manufactured.

    • They have done this before, claiming to have hit mantle pockets ( possible as they are in a general rift area and don't have to drill as far ) and had been producing steam from it.

      Unfortunately, as you point out, the steam is extremely corrosive. The last time they did this ( several years ago ) several valves completely corroded and they had to abandon the well rather than try to replace the valves and corroded piping.

    • Re:anyone know.. (Score:4, Informative)

      by Teun ( 17872 ) on Thursday December 15, 2016 @10:40AM (#53490075) Homepage
      A valid question.
      But these days we do have metallurgical solutions.

      During 1979-1980 I was involved in the testing of steam wells near the Vesuvius volcano in Italy.
      The tapped reservoirs were between ~1200 and ~1800 meters deep and the bottom hole temperature was close to 350degC, on full flow around 250 degC at the wellhead..
      Producing them caused a hellish noise and a lot of steam, we calculated the gross output of a single well was around 50MW.

      After a while the measurements showed a rather serious problem, lot's of sulphur, heavy metals and other nasty minerals were included in the steam and eventually in the condensed water.
      Cleaning this up would leave around 15MW of energy but it would be hugely expensive.
      Although the wells still exist they have never again been produced.

      Back to your question about the pipes used, in the day they were some Chrome alloy suitable for the expected temperatures and pressures but any serious corrosion would have a time factor.

      I found it interesting that starting up the wells (very slowly and controlled) caused the wellhead to rise some 3 meters due to the heat driven expansion of the pipes. Shutting them down required the same kind of care.

      • That issue happens with open cycle, this project is closed cycle, so there is nowhere for the heavy metals to enter to piping.

  • Nothing ventured nothing gained. I particularly like this bit:

    If the drill does hit magma, because it is under pressure, it would be likely to come to the surface rapidly, he explained. "It would come out rather like lancing a boil or popping a spot. It would cause huge problems for the drilling operation itself, but it is unlikely to cause anything more significant than that."

    Would not want to be on that drill crew. Falling into lava or getting splashed with lava is just about the worst way I can imagine to die.

    • Re:Interesting... (Score:5, Informative)

      by Rei ( 128717 ) on Thursday December 15, 2016 @08:38AM (#53489319) Homepage

      We've hit magma before (drilling at Krafla) - only the second time in the world that it happened. Totally by accident. The magma backed a couple dozen meters up the borehole, then stopped.

      The first time anyone ever accidentally drilled into a magma chamber was in Hawaii; they immediately sealed up the borehole as a result. Here they just decided "what the heck..." and started pumping water down it to see if they could turn it into a production well. And the performance turned out to be superb.

    • by Kjella ( 173770 )

      Would not want to be on that drill crew. Falling into lava or getting splashed with lava is just about the worst way I can imagine to die.

      I'd think falling into 1000C melted rock would make you pass out pretty much instantly, anything that kills me in under a minute would at least be over pretty quick. The worst kinds of dying seem to be where your body or mind is slowly falling apart with increasing pain and incapacitation while taking a really long time to actually kill you. That some of them long for a quick death to the point of wanting assisted suicide says a lot. What's worse than losing your life is having a life not worth living.

    • I hear polonium poisoning is pretty slow, unpleasant and untreatable.
    • I was on fire once, there's a limit to how much pain registers, lava would be over the limit really quick.

  • by CrimsonAvenger ( 580665 ) on Thursday December 15, 2016 @08:24AM (#53489263)

    Or not.

    "supercritical steam" just means steam at above the boiling point of water at whatever pressure applies. More specific heat than "saturated steam" (steam at the boiling point of water at the applicable pressure), but otherwise pretty much the same as any other steam....

  • by Anonymous Coward

    http://www.imdb.com/title/tt0059065/

  • Have they done anything to address the issue of the earthquakes this can produce? [npr.org] Earthquakes (especially large numbers of microearthquakes) are why geothermal energy is off the table because it damages all of your buildings and infrastructure. To make things worse, the effects of lots of earthquakes on wildlife isn't well understood.

    • by dbIII ( 701233 )
      Just as well you can't be held accountable - that confusion of scale is like comparing a pond ripple to a tsunami.
      Cocaine ravaged ex-DJs go on like that but do you really want to come across the same way? I don't think you have actual brain damage as an excuse.
      • that confusion of scale is like comparing a pond ripple to a tsunami.

        A drop of water won't damage a rock but a drop of water per second will quickly wear away a rock. In the same way, damage isn't caused by one microeathquake, it's the cumulative effect of hundreds or thousands of them over years.

        • by dbIII ( 701233 )
          Based on what exactly?
          Sorry you come across as the same sort of loonie as the "one windmill will change the climate" guys. You may want to explain your reasoning behind your odd statement or it will be assumed that no reasoning was applied at all.

          Why will these wells change things when millions of other wells drilled for different purposes have not?
    • by Rei ( 128717 )

      We mainly just get quakes when doing water injection for enhanced recovery. Quakes don't propagate well here, and the plants aren't exactly in the middle of major cities.

    • by Ol Olsoc ( 1175323 ) on Thursday December 15, 2016 @10:06AM (#53489779)

      Have they done anything to address the issue of the earthquakes this can produce? [npr.org] Earthquakes (especially large numbers of microearthquakes) are why geothermal energy is off the table because it damages all of your buildings and infrastructure. To make things worse, the effects of lots of earthquakes on wildlife isn't well understood.

      It's Iceland, They have volcanoes and lava and new islands forming, and earthquakes all the time anyway. You could shoot every evil hoomin, appoint some pond algae prime minister, and they'd still have all of the above.

      Perhaps a lawsuit against the Mid-Atlantic Ridge is in order.

    • You say that like anybody in Iceland is going to notice less than 4.0 earthquakes [iris.edu], Iceland is always shaking a little bit.

  • by Anonymous Coward

    If a fluid is supercritical it does not have a distinct phase. Steam is vapor phase. You can either have supercritical water, or you can have water vapor. If you have one, you do not have the other.

  • by fraxinus-tree ( 717851 ) on Thursday December 15, 2016 @08:40AM (#53489335)
    Most power plants (natural gas, oil or coal) run on supercritical steam anyways, at least in their designed power level. The technology is neither new nor rare. The need to run on "dry" steam for efficiency is known at least from steam locomotives. The only modern power-generating subcritical steam systems I know of are some nuclear power plants where the reactor expects some of the cooling water in it to stay liquid (read: dense) because it serves as neutron moderator as well.
  • by fubarrr ( 884157 )

    >It should be noted that Iceland also uses direct geothermal

    It still can't beat nuclear district heating and having your tap water coming out of reactor cooling circuit (Bilibino)

    • by Teun ( 17872 )
      Oh?
      Even when like in the case of Iceland all you need to do is build some pipelines and heat exchangers?
  • Such scary FUD (Score:5, Informative)

    by wbr1 ( 2538558 ) on Thursday December 15, 2016 @08:57AM (#53489417)
    Supercritical just means that it is above the vapor point but cannot vaporize due to the pressure it is under. Dealing with high temperatures and pressures is a very surmountable engineering challenge.

    Did you know your decaf latte probably used supercritical CO2 to decaffeinate the beans? Supercritical CO2, also at very high pressures, is a very good solvent and used in many industries.

    Have some fun videos about the latter.

    https://www.youtube.com/watch?... [youtube.com]

    https://www.youtube.com/watch?v=-gCTKteN5Y4

    • by swb ( 14022 )

      I think I read they use supercritical CO2 for extracting THC from marijuana plants, or were at least migrating to it from earlier systems that used butane as the solvent.

      • Depends on what you are after. butane as a solvent is less selective than supercritical CO2, but more selective than something like ethanol. the CO2 gets the main thc canabinoids but misses many of the minor THCs and CBDs. Butane gets some of the minor THCs and a lil bit of the terpenes. ethanol grabs most everything.

        • by swb ( 14022 )

          I don't really know much of the chemistry involved, all I've heard is that butane extraction is relatively simple, operating at reasonable pressures and the most complex moving part is a vacuum pump for extracting out the butane. The downside being the butane is flammable or potentially explosive if mishandled.

          I've also heard that butane leaves a foul taste in extracts, but I'm not sure if that's from crappy sources of butane or bad extraction technique.

          CO2 supposedly is better tasting and not flammable, t

  • by NReitzel ( 77941 ) on Thursday December 15, 2016 @09:14AM (#53489507) Homepage

    Tapping geothermal energy is a great idea, but it's not precisely renewable.

    The process, whether using natural (in place) water or by water injection, is removing paleolithic heat from a piece of solidified rock. That rock only has so much heat in it and the process of tapping that heat cools it. There are already geothermal fields in Northern California (The Geysers) that are producing reduced power output due to local cooling.

    The upside with deep geothermal is that there is a whole lot of crust to drill into and depleted wells can be deepened. With better grid technology more remote geothermal sources can be tapped including shallow magma.

    There is a lot of energy available but technically speaking it is neither infinite nor renewable any more than anthracite coal fields were renewable. At the turn of the 20th century mining companies were looking forward to mining these vast fields of coal forever.

    • It is renewable (Score:5, Informative)

      by Yaakov2k ( 34463 ) on Thursday December 15, 2016 @09:41AM (#53489621)

      You appear to think that most of the heat at the earth's core is residual, in which case presumably tapping this heat would "let it out" and we would eventually run out. This is not the case. The vast majority of the heat (90% or more) is from the decay of radioactive elements. Thus, the heat is being produced continually and is renewable until the radioactive elements decay (should be a good source of heat for at least a few billion years, probably much more). This means that tapping into the earth's core is not going to ruin the insulation of our crust and cause all the stored up heat to get out, because the core isn't really hot because of residual heat – regardless of what people are taught in grade school.

      Saying geothermal heat like this is not renewable is ultimately like saying that hydropower is not renewable because at some point the sun will expand and the earth will get so hot that all the water in all the rivers evaporates – which

      • Riiigggghhhttt... and when our planets core ceases to be liquid and shifting around, then our planet stops turning and we turn into a frigid ice-ball like Mars... I'm gonna blame Iceland. ;-)
    • by lazarus ( 2879 )

      This sounds like bad news for the Earth's outer core (and eventually our magnetic field and atmosphere). Serious question: Is the cooling of this a long-term problem or will it re-heat on the basis of the mass of the earth over time?

      I'm assuming that this is not dangerous so long as the total rate at which we cool the outer core does not exceed the capability of it to re-head through gravity. Is that correct? (not a geologist).

      • by Yaakov2k ( 34463 )

        It is renewable: it is being heated continually by radioactive decay (see my other post in reply to the original post). No need to worry about cooling off the core.

    • by Ol Olsoc ( 1175323 ) on Thursday December 15, 2016 @10:16AM (#53489863)

      Tapping geothermal energy is a great idea, but it's not precisely renewable.

      You are correct. There are no precisely renewable energy sources. The wind? Nope, Solar? Nope, pretty clear that stars have a finite lifetime, and are not precisely renewable. But on a human time scale, from when homo has been around, to our likely extinction, it will fit a non-pedantic definition of renewable.

      • But on a human time scale, from when homo has been around, to our likely extinction, it will fit a non-pedantic definition of renewable.

        Only if you ignore facts, which we glean from history. And the history is this: The Calpine geothermal plant at The Geysers is situated upon the most geothermally active location on the planet (at least, on the surface) and that is not sustainable. They have to pump primary treated sewage (no other water being available in California) into the ground in order to keep the system producing steam. This in turn creates seismic activity in the region, which is absolutely riddled with fault lines both new and old

        • But on a human time scale, from when homo has been around, to our likely extinction, it will fit a non-pedantic definition of renewable.

          Only if you ignore facts, which we glean from history.

          My point is that there is not any renewable energy source in the universe, unless the second law of thermodynamics is null and void. Our home star will eventually not provide any significant energy, the whole earth's core will eventually cool. If OP is going to get pedantic, I reserve the right to peg that p-meter. In the meantime, perhaps we can just call everything alternative energy sources, rather than a term that is generally accepted, but in the end, is pedantically incorrect for any energy source, be

  • Picture an unimpressed Balrog chained to a treadmill...

  • Then we should do this at Yellowstone. If we harnessed enough energy from there, we might be able to stave off a caldera super event, which is overdue.
  • by blogagog ( 1223986 ) on Thursday December 15, 2016 @11:18AM (#53490365)
    If my calculations are correct, 5km down is right around where the balrogs live...

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