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You can have geothermal power everywhere if you drill deep enough

405 points by stareatgoats 5y ago

grey_earthling 5y ago
I used to read Treehugger regularly, until a couple of years ago when they deleted their RSS feed. I'd forgotten the site existed until just now. (Make of that what you will.)
raxxorrax 5y ago
> Meanwhile, the heat vitrifies the side of the hole, turning it essentially into a glass pipe I think this is pretty essential and maybe even more important than the depth. Until now it was not economically feasible because the porous rock did swallow a lot of the circulated water in such a drilling. But this technique seems to solve that problem pretty effectively.
- fly-guy 5y ago
  Conventional boreholes are cased with steel and cement. Vitrified walls would theoretically save that material cost (if it actually worked)
mikeyouse 5y ago
There’s some very interesting work being done with shallower, cooler temperature geothermal combined with rankine cycle generation as well: https://mobile.twitter.com/OrmatInc https://mobile.twitter.com/OrmatInc
crgi 5y ago
Anyone thinking about earthquakes when going that deep? In Switzerland they had to stop some geothermal projects after triggering earthquakes while drilling deep.
- pg_bot 5y ago
  The geothermal projects in Switzerland (and South Korea) used pressurized water to form cracks within the rock (similar to fracking). Also typical geothermal projects need to be near fault lines since that is where the low hanging fruit is. Since this method will forgo those steps you should greatly minimize the likelihood of triggering an earthquake.
aaron695 5y ago
Schroedingersat 5y ago
Assuming this works, tech still won't save us alone. Pure thermal (ie. just energy, no GHG) climate change is right around the corner if energy use keeps going up exponentially and we keep reducing earth's albedo. Ecosystems are still being obliterated for cattle and mining. All ghg free electricity will do is buy a few decades to end (and in the west, reverse) growth. Possibly the only thing that will give civilisation a chance to find a solution, but not a solution. We should be finding ways for people in the west to live more like developing nations and still thrive, not trying to turn developing nations into the west.
- eru 5y ago
  > Pure thermal (ie. just energy, no GHG) climate change is right around the corner if energy use keeps going up exponentially and we keep reducing earth's albedo. What makes you think so? What growth rates are you assuming? How long is your time horizon?
  - napier 5y ago
    If and when we get to that point various theoretical methods are available for bleeding off surplus heat; one of them is aiming a neutron beam at the moon. One upside of all this learning the hard way via profligate energy generation and accidental geoengineering taking place since the industrial revolution is that it opens the door to possibilities of regulating the impact of Milankovitch cycles on our civilization and biosphere.
    - eru 5y ago
      If you can concentrate energy, eg into a neutron beam, then it's not waste heat. It's a form of energy you still can get useful energy out of. The only thing you can do with true waste heat on the scale of earth is to radiate it into space. You might want to look into eg https://en.wikipedia.org/wiki/Second_law_of_thermodynamics https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
      - napier 5y ago
danans 5y ago
A recent podcast interview with Quaise energy's CEO. https://www.woodmac.com/news/opinion/the-interchange-recharged-podcast-quaise-energy-digs-deep--into-the-world-of-geothermal/ https://www.woodmac.com/news/opinion/the-interchange-recharg...
anonporridge 5y ago
Something I've always wondered. Wouldn't massive scale geothermal end up pumping more heat into the atmosphere that otherwise wouldn't be there? In contrast, the energy collected by solar and wind generators is from the energy added to Earth by the sun and would be energy in our atmosphere regardless of whether or not we collect it. But it seems like the heat inside the Earth's core should be fairly well insulated by the lithosphere, and it only slowly leaks out over time. If we start pulling that energy out at a faster rate to generate electricity, could that have a noticeable net increase on total energy under the atmosphere, or is it such an insignificant amount of energy relative to the sun's to not even bother worrying about?
- visarga 5y ago
  How is that different from nuclear?
- Uily 5y ago
  Yes, but it will be orders of magnitude less than the sum total energy of solar energy across the total surface of the earth.
  - eru 5y ago
    Similarly: Nuclear power plants, as nearly all power plants, work by heating water. That heat has to go somewhere eventually. But the amounts you'd need to make any difference to the atmosphere (compared to solar radiation) would be truly humongous.
    - anonporridge 5y ago
      I don't know if this would be any extra heat, because the radioactive material would already be decaying anyway if it was left in its natural state. Maybe the same problem where radioactive material would be left mostly underground and insulated where its heat would leak slowly. Then again, part of the Earth's core heat comes form radioactive decay. So in a way, geothermal is an indirect form of nuclear fission.
Glawen 5y ago
Yeah right. They drilled in Strasbourg, France, to get this "free" energy. When they entered production, the city was experiencing an earthquake every month, waking the city at night. After a magnitude 4 earthquake, they finally shut down the plant. A town in Germany is devastated also due to geothermal power: https://en.m.wikipedia.org/wiki/Staufen_im_Breisgau https://en.m.wikipedia.org/wiki/Staufen_im_Breisgau
- eru 5y ago
  Assuming this is a real problem, wouldn't you just put your geothermal power plant well outside of any city? Doesn't even have to be somewhere where there are no buildings. Just somewhere where hardening the few existing buildings against small earthquakes etc won't be too expensive.
  - Fiahil 5y ago
    > Just somewhere where hardening the few existing buildings against small earthquakes etc won't be too expensive. So, expending twice on a bad idea ? Seriously, what do you think will happen ? And even it was technically possible, how do you insure a company like that ? Will the plant operator be responsible for the repairs and damages when they destabilize an entire region ?
    - eru 5y ago
      > So, expending twice on a bad idea ? Seriously, what do you think will happen ? What do you mean? A few really minor earthquakes are all that was reported by the comment I was replying to. So I'd assume more really minor earthquakes. > And even it was technically possible, how do you insure a company like that ? The usual way of paying an insurance company? > Will the plant operator be responsible for the repairs and damages when they destabilize an entire region ? Depends on the jurisdiction. But sure, you can make the plant operator responsible for that and responsible for having gigantic insurance coverage. (Just look at whatever liability people who operate dams have today. A breakage of a major dam would also devastate entire regions. So whatever arrangements are good enough for that use case are probably good enough here.)
imgabe 5y ago
How much energy is in the core of the Earth? What happens if we cooled the core to the point that it became solid? I’m guessing that would be bad, but is it something that’s not conceivably possible on any human timescale?
- chii 5y ago
  It would take quite a lot to cool the core.
- ComradePhil 5y ago
  We can pump heat into the core when it is hotter in the surface. So, it can also work as a battery.
  - axiolite 5y ago
    > We can pump heat into the core when it is hotter in the surface. Were you expecting a massive meteor impact in the near future that the rest of us are unaware of? If not, exactly how were you planning to get enough heat at the surface of the Earth to warm-up the core?
    - ComradePhil 5y ago
      Do you think we drill to the very core to get thermal energy? Well, I have disappointing news for you: The earths radius is 6,371 km; for thermal plants, we dig like 5 km. While the core is 5000 degrees celcius, the point we dig to is more like 150. Concentrated solar power can generate 1000 degree celcius. If we pump this down when we have excess, the area remains hotter than it would otherwise be... letting us use it when the sun sets. This can also work through much longer timescales, like you could dump energy heat down in the summer and harvest it in the winter. The post I was replying to was worried about gradual loss of core heat. This will be minimized if we pump heat in.
- pm90 5y ago
  Not until humanity becomes a type 2 Civilization. Which seems like at least a 1000 years away.
a1371 5y ago
A lot of people like to talk about nuclear as a climate solution. Geothermal is the most gargantuous nuclear plant we can fathom, all we have to do is to extend a pipe and harvest it. Here is the thing, a lot of that tech is coming from oil and gas. An industry with a track record of leaving the land they enter in terrible shape. I think we have to start over with geothermal and look at it more like hydro electricity. We should harvest the electricity on the way down, not the way up. I wish I'd get rich enough one day to devote my life to this.
- ComradePhil 5y ago
  > We should harvest the electricity on the way down, not the way up. Could you please explain what you mean?
  - tschwimmer 5y ago
    I have to assume GP means that we should extract the geothermal heat at the bottom of the well/borehole, not by bringing the oil back up to burn it.
    - a1371 5y ago
      No, I mean we should use the motion of the water, not its heat. Like in hydroelectricity where water spins a turbine instead we are using a steam generator like gas fired plants
      - manarth 5y ago
        A steam turbine essentially _does_ use the motion of the water. In conventional hydroelectricity, gravity causes the motion through the energy differential of the waters' height. In a steam turbine, the potential energy is from the high temperature of the water, and the energy input to rotate the turbine comes from the temperature differential of the steam cooling. In theory you could capture the hydroelectric energy of the water on its way down a 12 mile hole, but that gravitic potential energy is negligable compared to the energy difference between superheated steam and water.
russellbeattie 5y ago
I suggested an idea for a backyard geothermal generator in a comment a few months ago and got shut down because it would be too costly to drill the hole. But hey now! This microwave drill might do the trick! Hmm. Are magnetrons and gyrotrons the same thing? Probably not. So we can't rip apart an old microwave oven and start drilling holes out back just yet. Damn. https://news.ycombinator.com/item?id=27777665 https://news.ycombinator.com/item?id=27777665
TeeMassive 5y ago
I've always wondered, but geothermal plants are basically huge radiators. If Humanity taps into this energy in industrial scale for centuries, would we cool the planet's mantle and core enough to have repercussions on the magnetic field for example?
- modeless 5y ago
  20 km is 0.3% of the way to the center of the earth. It seems unlikely that anything we do there could affect the core in a meaningful way.
modeless 5y ago
Converting existing fossil fuel plants sounds awesome. But they haven't actually drilled any deep holes with this new technology yet, right? They're going to go from nothing to drilling almost twice as deep as the deepest hole ever drilled by humans, in four years?
jokethrowaway 5y ago
The comments on the article make me lose faith in humanity. Amazing technology though, this coupled with solar could really make people independent of centralised energy systems
- lwouis 5y ago
  Independence is a pipe-dream. You always depend on others and physical resources. If you install a solar panel to "become independent from centralized energy systems", you're moving from a dependence to established energy networks to another type of dependence. You now depend on people making, delivering, maintaining panels for you. As well as the batteries to store the energy. No-one can make or repair this take themselves. You just moved the dependence from one system to another. The current system is also battle-tested and mutualized. Outage see lots of people on deck to fix things. If your solar installation panel breaks it's your individual problem and it will quickly reveal just how dependent you actually are. The only way to be independent of other humans would be to live a lifestyle which requires only rudimentary knowledge, and the muscles of your body. Probably only hunter-gatherer. Anything beyond that means you rely on knowledge, skills, and muscles of other, and dependent on them for your life. Maybe you knew all this, but it may still be useful for other readers to realize since these days we hear a lot of prophets telling us how we should increase our independence by installing solar panels or wind turbines. And people don't think twice about where these come from, and who will maintain them.
  - qiskit 5y ago
    > If you install a solar panel to "become independent from centralized energy systems", you're moving from a dependence to established energy networks to another type of dependence. You now depend on people making, delivering, maintaining panels for you. As well as the batteries to store the energy. Thank you. People claim they are independent because they are off-grid and using solar panels. But are they really? Solar panels last about 10 years and then what? Of course they are dependent on the grid that provides them the solar panels and batteries.
CyanLite4 5y ago
I wonder if you could optimize it a little further to get energy from both directions… Energy produced in the way up (heated water) and on the way down (gravity-Fed turbines)
Animats 5y ago
Microwave drilling. It's a known thing at small scale.[1] If it can be done at larger scale, it ought to have other applications. Doing it downhole at the end of a long pipe string is going to be much harder than doing it in a factory. So why isn't this an industrial machining process already, like plasma cutting? GA Drilling was pushing plasma drilling back in 2018.[2] They're still pushing it, but not making holes. The University of Minnesota was pushing electro-pulse boring in 2015.[3] Again, no deep holes. There's something called ThermoDrilling, which, despite the name, is more like a water jet cutter.[4] Successful projects are still using mechanical drilling.[5] So there are a lot of deep hole drilling approaches being studied. Anything that works would be used by the oil and gas industry, and if they're not trying it, one suspects it might not be working. [1] https://www.researchgate.net/publication/270653673_Microwave_Drilling_of_Materials https://www.researchgate.net/publication/270653673_Microwave... [2] https://www.gadrilling.com/ https://www.gadrilling.com/ [3] https://experts.umn.edu/en/publications/electro-pulse-boring-epb-novel-super-deep-drilling-technology-for https://experts.umn.edu/en/publications/electro-pulse-boring... [4] https://www.geodrillinginternational.com/deep-geothermal/news/1385347/thermodrill-an-innovative-drilling-system-for-deep-geothermal https://www.geodrillinginternational.com/deep-geothermal/new... [5] https://geothermalengineering.co.uk/united-downs/ https://geothermalengineering.co.uk/united-downs/
- leoedin 5y ago
  This could also have good use for ground source heat pumps - they're the most efficient, robust and consistent source of domestic heating we have, but require fairly deep (60m ish) boreholes. If digging could be quicker, easier or faster these heat pumps could be installed everywhere.
  - hectormalot 5y ago
    I have one of those. The well is 170m deep. Took 2 guys about half a day to drill it, so that actually doesn’t seem excessive in terms of time required (mostly sand, no rock below my house).
    - NavinF 5y ago
ZeroGravitas 5y ago
This sounds like cool tech, and the re-use of the existing generation assets is clever, but just running costs of the steam part of an existing plant struggles to compete on a financial basis with wind turbines and solar PV so it'll probably only ever be a niche thing. Shared ground loops connected to heat pumps are a more boring tech with more potential to have a global scale impact.
- erosenbe0 5y ago
  You cut out the combustion stack and boiler here so it has to be much cheaper than fossil fuel turbine?
  - ZeroGravitas 5y ago
    I wasn't even counting the combustion part, just the heat to steam to electricity part (common to coal and nuclear plants). I had assumed they would need to transfer the heat rather than pipe geothermal steam directly into the turbine, but either way, solar and wind is very cheap and hard to compete with. Even magical free energy connected to a steam turbine struggles when you do the sums, which is the baseline before you start including cost and risk from super deep drilling.
- p1mrx 5y ago
  Assuming that people commit to buying 24/7 carbon-free energy at any price, on-demand generation like geothermal will be quite valuable during the times when wind and solar are underperforming. So geothermal will mainly compete with nuclear and storage, not wind and solar.
  - ZeroGravitas 5y ago
    Yep, and like nuclear, it has a high up front cost that needs to be amortized over near constant use to be viable which means it prices itself out of that role pretty quickly compared with say green ammonia fired peaker plants that mostly incur costs when actually used and also use the green energy being produced in large quantities.
cryptica 5y ago
I hope that investors did the math to ensure that the energy used to dig such a deep hole with microwaves doesn't end up consuming more energy than the hole will generate over its lifetime... Will the hole crack irreparably after a few months? Nowadays, there seems to be an epidemic of engineering neglect in terms of capital allocation. A lot of wealthy individuals who have the capital to invest in such projects do not seem to have the engineering mindset (or no longer do) to see through greenwashing BS. "It's all about the people" is BS. These days, there are charlatans everywhere and they seem to have monopolized all the billionaires.
- re6fae5Wied5tha 5y ago
  I can't imagine it takes more than a few circuits of water through the bore to recover all of the energy, the static column of water alone would contain a non-trivial fraction of the energy required to drill the bore after equilibrating.
dzhiurgis 5y ago
A few Lithuanian names there. They’ve apparently tried geothermal in Klaipeda but faced salt water which was hard to handle. Generally Eastern European cities with centralised heating are very suited for geothermal. Except they’ll loose all that sweet sweet kickback from Russian oil dealer.
WalterBright 5y ago
If you drill a hole deep enough, you'll be unable to prevent the hole from collapsing in on itself. I wonder how deep that would be.
- kragen 5y ago
  Conventionally you fill the hole with mud with the same density as the rock, avoiding this problem. You couldn’t drill into the inner core that way because it’s liquid, and maybe at some shallower depth you’d run out of candidate mud materials that will stay liquid at the relevant temperature, but given the right mud I think you could pass the Moho. So far, though, the problem is breaking drill strings.
imranhou 5y ago
Is there a chance that the hole creates a mini volcano that cannot be stopped?
- erosenbe0 5y ago
  One assumes well blowouts will be a serious problem, as with any energy extraction.
- re6fae5Wied5tha 5y ago
  This is actually the risk I came here to mention about deep bores. Bore first, build later, otherwise you may be the unlucky winner of a fluid formation trapped under a rigid formation in the local geology. https://theconversation.com/a-mud-volcano-has-been-erupting-for-ten-years-and-scientists-are-still-undecided-what-caused-it-80827 https://theconversation.com/a-mud-volcano-has-been-erupting-...
suction 5y ago
And every dance move is "The Robot" if you imagine an advanced enough robot...
grecy 5y ago
I can't help but wonder if this means we can drill our own private hot springs wherever we want...
bencollier49 5y ago
How much geothermal power would you need to extract to completely cool the core of the Earth?
- themerone 5y ago
  All of it.
z3t4 5y ago
If we do this in large enough scale, will the earth eventually cool down?
throwaway0332 5y ago
> True geothermal energy is truly green Reminder: few energy sources do not add heating to the atmosphere during the whole energy lifecycle! It's the ones that *subtract* energy from the environment in the first place: solar, wind, dams, tidal energy. Other sources (including geothermal, nuclear, oil ...), even if we could produce a 100% efficient power plant, are still extracting energy that would otherwise stayed "locked-in" somewhere. Keep in mind that virtually all electrical energy produced turns into heat released in the atmosphere.
- alex_smart 5y ago
  I think one relevant question is: how does that amount of energy compare to the energy that the earth is bombarded with by the sun anyways? If it is miniscule (say less than 1%) in comparison, will that have a significant impact on global warming? https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026 >A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use. So even if we get all of our current energy needs from these sources, that is less than 0.01% of the energy earth gets from the sun. Is that going to have a significant effect on the temperature of the earth?
- andy_ppp 5y ago
  Energy from heat is never discussed with climate change, only energy from the greenhouse effect. Do you know what percentage of each (roughly) human activity is causing?
FrankyHollywood 5y ago
Drilling is not the problem which stands in the way for using earth warmth. It is pollution of ground water, risk of earth quakes, transportation of the heat, local cool down and having to drill new wholes. In Europe we have tried, and tested with wholes up to 1km depth but it is not as ideal as one might think. Otherwise it would have been used on a large scale already.
giantg2 5y ago
In regards to the deeper drilling... wasn't there an article recently that the core is cooling faster than previously thought? Do we know how it could affect the earth if we are doing this at a large scale? Are we going to cause problems further down the road because we don't know enough.
twobitshifter 5y ago
I can’t find what the progress or results of the arpa-e project were either on the quais website or elsewhere. https://arpa-e.energy.gov/technologies/projects/millimeter-wave-technology-demonstration-geothermal-direct-energy-drilling https://arpa-e.energy.gov/technologies/projects/millimeter-w... The Altarock energy site is currently showing a 503. Altarock from Seattle won the arpa grant and were noted as an “affiliate” of Quais in the ieee article. https://spectrum.ieee.org/altarock-energy-melts-rock-with-millimeter-waves-for-geothermal-wells https://spectrum.ieee.org/altarock-energy-melts-rock-with-mi...
ineedasername 5y ago
Whenever the topic comes up, it always seems strange that going more than just a handful of mi/km down is an incredibly difficult task. Because it makes me realize-- or remember-- that the most life-hostile & technology-defying environments aren't in far off geographic locations or far out in space, they're a constant presence just under my feet. A shorter distance from me right now than I travel in my daily commute. That as space enthusiasts (rightfully) speculate or plan the future above our heads, there are incredible things going on beneath our feet at forces and temperatures that also produce very exotic materials and even the prospect of untapped clean energy just a short distance away from every single place in the planet. (Assuming that drilling down for geothermal power isn't horrible for the environment?) Just another example of how very little in the natural world is truly mundane and there are incredible things everywhere.
gumby 5y ago
> The problem is it has only been practical in volcanic regions or near the edges of tectonic plates, where cracks in the Earth's crust allow steam to form close to the surface like in Iceland or the geysers in California. Incredibly, California has managed to kill its geysers. Apparently when Geyserville was settled there were puffs of steam coming out all over the place. Now the geothermal plant there injects wastewater into the rock and then drives its turbine with the steam that comes back.
pharke 5y ago
If we converted all energy production to geothermal, would it be possible to significantly increase the cooling of the Earth's core? The flow from the Earth's core to the surface is estimated at 47±2 terawatts[0] The total energy supply for 2017 was 162,494 TWh[1] World energy demand is expected to grow 27% by 2040 Currently, heat escaping from the Earth accounts for only 0.03% of Earth's total energy budget at the surface which is dominated by the 173,000 TW contributed by solar radiation[0] What effect would it have if the vented heat were equal to the amount contributed by the sun? [0] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget [1] https://en.wikipedia.org/wiki/World_energy_supply_and_consumption https://en.wikipedia.org/wiki/World_energy_supply_and_consum...
- originalvichy 5y ago
  I can be wrong but that number sounds so low that it might mean the energy at the literal surface, in the same vein as how much solar heat energy reaches the planet’s surface. I assume that the number is vastly greater if you measure the heat 1km below sea level for example.
- samatman 5y ago
  The only mechanism we would have for significantly increasing the cooling of the Earth's core would involve heading the atmosphere well past the habitable band. Ultimately if heat isn't radiating from the atmosphere, it isn't leaving the planet.
- ant6n 5y ago
  The bigger question is whether we will heat up the surface top much, given that the energy would be produced by a heat engine. (I suppose you could build a heat engine by using the temperature differentials of different underground layers, although I've never seen that proposed)
- RugnirViking 5y ago
  surely there must be some numbers wrong here? How can the total energy supply be only just barely less than the entire amount of energy applied to the planet by solar radiation? Is it suggesting that covering the entire surface of earth with 100% efficient solar panels would just barely cover 2017's power supply? Edit: ah I see, world energy is in terawatt hours for an entire year, wheras planetary solar energy is terawatts in a single hour
throwaway9870 5y ago
You just don't "use" heat to make electricity. You need some sort of heat engine running a cycle. All those require temperature differential. This is basic thermodynamics and isn't going to change with new technology. This temp differential is what is required to extract useful energy. So I don't understand why they talk about material at a certain temp having energy compared to oil. If we lived on a planet that is uniformly 1000 deg F, it wouldn't help us because we don't have a temp differential to convert thermal energy to electric. Nowhere in the article did I see them mention temp differential and where they are going to dump the waste heat? Nuclear plants get crapped on because they dump heat into adjacent water bodies, how is this different?
- sidewndr46 5y ago
  Your point is well made. If all it took was heat, then climate change would probably be the best thing ever. More heat captured from the sun would give us more energy.
  - hedora 5y ago
    Open challenge: Getting an elected US politician to seriously propose a space heat sink as a solution to climate change. There were some people seriously proposing big convection tubes that'd bootstrap columns of hot air, then passively pull surface air into the upper atmosphere. I can't find a link, but those wouldn't get to low earth orbit, so not a "space" technology.
    - sidewndr46 5y ago
      I've heard of launching some large mirrors into orbit, or a bunch of small mirrors that can link together in orbit. Then you use them to reflect some sunlight off into space. I have no idea how practical this is. The bigger concern would be if something goes wrong, you need to make the mirrors deorbit quickly.
      - hedora 5y ago
        You could set it so that some of the mirrors formed a parabolic collector and heated a molten salt column, etc on the surface. That'd have the same net effect as the giant heat sink (energy production from a heat engine, net negative flow of energy to the surface). Wasn't there a city builder that'd let you build such a thing, where it would sometimes lose calibration and burn a swath of the city to the ground?
rvalue 5y ago
and suffer the fate of krypton? sorry, I couldn't read the article without solving the question of energy cycle in my mind. renewable sources like solar, wind are kind of taking energy from outside, so in case of geo-thermal, if we keep using that, there is nothing thats balancing the equation.
- stareatgoats 5y ago
  You are right, this tech would cause the core to lose temperature at a slightly higher rate than otherwise. At the moment the earths core is cooling at the rate of 0.1 °C per million years from the current temperature of about 5,100 °C, interspersed with periods where the temperature loss is stopped or reversed because of gravity forces [0]. But any conceivable number of deep geothermic wells would not affect that rate in any measurable way. [0] https://en.wikipedia.org/wiki/Earth's_inner_core https://en.wikipedia.org/wiki/Earth's_inner_core
holoduke 5y ago
Wonder if one day we find out that thermal energy is cooling down earth too much. Reducing magnetic field around the earth which causes a huge reduction of our ozone layer and eventually even the entire atmosphere.
FlyNestor 5y ago
Hope this new technology will have success. You never know it can be the next Theranos.
charles_f 5y ago
Somewhat related, I used to think that residential geothermal heating was basically harvesting the steaming heat from the soil to your house. I figured that would require seating on a volcano. In fact it's using a heat pump, and liquid circulating in pipes burried a few feet underground to act as a thermal sink, to either heat or cool down a house. This works well because the temperature in the ground doesn't fluctuate much past 3ft. Pretty neat, and does not require to go down miles (though it's moving energy to/from ground rather than harvesting it and you still need an energy source for the pump)
- thescriptkiddie 5y ago
  A ground-source heat pump is technically not geothermal, because the bulk of the heat comes not from the earth but from the sun. You are basically using the soil as an enormous thermal battery which charges up in the summer and stays warm (relative to the air) through the winter. Real geothermal power plants are actually indirectly harvesting heat from the molten inner layers of the earth, which is mostly leftover from the the formation of the planet.
hsnewman 5y ago
Thanks, captain obvious.
theptip 5y ago
The idea of drilling deep geothermal to repurpose existing fossil plants is an elegant one. I imagine others have thought of this before, but it was new to me. Being able to take over the existing equipment (turbines, power transmission connections) seems appealing. Of course, it all depends on how expensive the drilling process is vs. the existing capital asset in the turbines, but maybe you could hit a price point where the repurposed geothermal plant is way cheaper than new solar / gas builds in the 2030s? This would be a transitional tailwind, just when we need it. Down the road, these plants would become more expensive because you'd also need to build new turbines/transmission lines. And at that time maybe solar or fusion is a cheaper solution (or not, who knows). But this could really help with the transition away from fossil fuels, if it was delivered next decade or two. A question - does deep drilling like this have any downsides, as fracking does? I'm guessing it's less bad since you're not pushing pressurized fluid into the bedrock, instead you're just making a pipe that contains the water.
- fly-guy 5y ago
  ENergy conversion equipment can't easily be re-purposed for geothermal. The temperatures are usually much lower, and the working fluids are often hydrocarbons instead of steam.
  - theptip 5y ago
    Quaise seems to think it's possible: > “What we intend to do is go to existing power plants—it could be a coal power plant, it could be a gas power plant, any of the thousands of fossil-fired power plants that exists in the United States and around the world—and we will propose to them to create a small geothermal field around them, which is matched to the turbine specification of the power plant. What comes out of the ground is steam that feeds into the turbine, and the rest is what they’ve always done. The turbine creates electricity. The plant is already connected to the grid,” https://www.powermag.com/a-game-changing-vision-for-geothermal-energy/#:~:text=%E2%80%9CWhat%20we%20intend,to%20the%20grid%2C https://www.powermag.com/a-game-changing-vision-for-geotherm... Could just be marketing fluff; I'm not an expert here. But don't coal plants exclusively use steam turbines? Edit: Seems that lots of energy in the US comes from steam turbines: https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php#:~:text=Steam%20turbines%20are%20used%20to%20generate%20the%20majority%20of%20the%20world%E2%80%99s%20electricity%20and%20they%20accounted%20for%20about%2044%25%20of%20U.S.%20electricity%20generation%20in%202020 https://www.eia.gov/energyexplained/electricity/how-electric....
tiku 5y ago
I always wondered why we didn't have laser drills yet, but microwave drills sound way cooler.
- perlgeek 5y ago
  Why not make it microwave lasers? :-)
abeppu 5y ago
> The microwave beam is hot enough to evaporate rock, and the vaporized rock is pumped back to the surface. Is this part harder than it sounds? Do you need to keep it as hot vapor until it gets to the surface? What do you do with it then? Presumably a 12 mile column of rock turns into a whole lot of vapor. Is it toxic? When vaporized rock cools, does it become just sand, or are there interesting/concerning chemicals left over? As a lay person, I'm never sure when I read about new tech to address environmental issues whether we're creating a new problem. We've spent generations aggressively pumping carbon out of the ground and into the atmosphere. Would a move towards rock-vaporizing drilling just mean aggressively pumping a bunch of silicon, iron, etc out of the ground and into the atmosphere?
- perlgeek 5y ago
  I don't really know, so take my answer with a grain of salt, but my lay understanding of chemistry and physics tells me: * Typically vaporized solids a fine powder they cools down in air, or otherwise deposit on cool surfaces * Fine rock powder could be hazard to lungs, but it shouldn't be too hard filter it out of the air that leaves the hole * Some rock materials contain sulfates or phosphates; letting those escape into the atmosphere in large quantities would be bad; but you could always let it recombine with the rest of the evaporated rock, rendering it inert. Such a process wouldn't be 100%, so this is something worth looking out for. Most wealthy countries require an environmental impact assessment before any such operation, so there's hope such things would be caught before they become a big problem.
doikor 5y ago
There is a project for deep geothermal heat in Finland. They specifically chose to do it here as it is one of the worst places to do it (have to drill really deep to get anything useful also the first 4 to 5km is just pure bedrock instead of some softer material). So they ended up making 6.4km deep holes where they got 121 degree (celcius) water. Once pumped up to ground level it cools down to 110 degrees but it is more then hot enough for district heating. The original plan was to got 9km deep but it was already hot enough at 6.4km so they stopped there to save money. https://www.st1.com/geothermal-heat https://www.st1.com/geothermal-heat
sandos 5y ago
Is this really, really renewable? I thought the heat down there was stored from before and will eventually peter out... We might all be dead by then but hey... not renewable!
- 4khilles 5y ago
  The sun will run out of hydrogen in ~5 billion years, solar isn't renewable either!
empressplay 5y ago
War is the mother of innovation
fallingfrog 5y ago
They can keep the microwave beam that tightly focused that the energy goes into making the hole deeper and not wider when the bottom is a target 6 inches across and 12 miles down? Wouldn’t it spread out and just absorb into the walls? This feels wildly implausible.
mvkel 5y ago
The problem with geothermal is there's no easy way to know where the "hot spots" are without drilling, which comes at a high cost.
joshspankit 5y ago
What would happen if literally everyone switched to geothermal tomorrow? Would we affect the core of the earth by extracting it’s heat at our current global usage? At double or triple our usage as the world gorges itself on this new source of clean power?

405 points by stareatgoats 5y ago

I used to read Treehugger regularly, until a couple of years ago when they deleted their RSS feed. I'd forgotten the site existed until just now. (Make of that what you will.)

raxxorrax 5y ago

> Meanwhile, the heat vitrifies the side of the hole, turning it essentially into a glass pipe I think this is pretty essential and maybe even more important than the depth. Until now it was not economically feasible because the porous rock did swallow a lot of the circulated water in such a drilling. But this technique seems to solve that problem pretty effectively.

fly-guy 5y ago
Conventional boreholes are cased with steel and cement. Vitrified walls would theoretically save that material cost (if it actually worked)

mikeyouse 5y ago

There’s some very interesting work being done with shallower, cooler temperature geothermal combined with rankine cycle generation as well: https://mobile.twitter.com/OrmatInc https://mobile.twitter.com/OrmatInc

crgi 5y ago

Anyone thinking about earthquakes when going that deep? In Switzerland they had to stop some geothermal projects after triggering earthquakes while drilling deep.

pg_bot 5y ago
The geothermal projects in Switzerland (and South Korea) used pressurized water to form cracks within the rock (similar to fracking). Also typical geothermal projects need to be near fault lines since that is where the low hanging fruit is. Since this method will forgo those steps you should greatly minimize the likelihood of triggering an earthquake.

aaron695 5y ago

Schroedingersat 5y ago

Assuming this works, tech still won't save us alone. Pure thermal (ie. just energy, no GHG) climate change is right around the corner if energy use keeps going up exponentially and we keep reducing earth's albedo. Ecosystems are still being obliterated for cattle and mining. All ghg free electricity will do is buy a few decades to end (and in the west, reverse) growth. Possibly the only thing that will give civilisation a chance to find a solution, but not a solution. We should be finding ways for people in the west to live more like developing nations and still thrive, not trying to turn developing nations into the west.

eru 5y ago
> Pure thermal (ie. just energy, no GHG) climate change is right around the corner if energy use keeps going up exponentially and we keep reducing earth's albedo. What makes you think so? What growth rates are you assuming? How long is your time horizon?
- napier 5y ago
  If and when we get to that point various theoretical methods are available for bleeding off surplus heat; one of them is aiming a neutron beam at the moon. One upside of all this learning the hard way via profligate energy generation and accidental geoengineering taking place since the industrial revolution is that it opens the door to possibilities of regulating the impact of Milankovitch cycles on our civilization and biosphere.
  - eru 5y ago
    If you can concentrate energy, eg into a neutron beam, then it's not waste heat. It's a form of energy you still can get useful energy out of. The only thing you can do with true waste heat on the scale of earth is to radiate it into space. You might want to look into eg https://en.wikipedia.org/wiki/Second_law_of_thermodynamics https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
    - napier 5y ago

danans 5y ago

A recent podcast interview with Quaise energy's CEO. https://www.woodmac.com/news/opinion/the-interchange-recharged-podcast-quaise-energy-digs-deep--into-the-world-of-geothermal/ https://www.woodmac.com/news/opinion/the-interchange-recharg...

anonporridge 5y ago

Something I've always wondered. Wouldn't massive scale geothermal end up pumping more heat into the atmosphere that otherwise wouldn't be there? In contrast, the energy collected by solar and wind generators is from the energy added to Earth by the sun and would be energy in our atmosphere regardless of whether or not we collect it. But it seems like the heat inside the Earth's core should be fairly well insulated by the lithosphere, and it only slowly leaks out over time. If we start pulling that energy out at a faster rate to generate electricity, could that have a noticeable net increase on total energy under the atmosphere, or is it such an insignificant amount of energy relative to the sun's to not even bother worrying about?

visarga 5y ago
How is that different from nuclear?
Uily 5y ago
Yes, but it will be orders of magnitude less than the sum total energy of solar energy across the total surface of the earth.
- eru 5y ago
  Similarly: Nuclear power plants, as nearly all power plants, work by heating water. That heat has to go somewhere eventually. But the amounts you'd need to make any difference to the atmosphere (compared to solar radiation) would be truly humongous.
  - anonporridge 5y ago
    I don't know if this would be any extra heat, because the radioactive material would already be decaying anyway if it was left in its natural state. Maybe the same problem where radioactive material would be left mostly underground and insulated where its heat would leak slowly. Then again, part of the Earth's core heat comes form radioactive decay. So in a way, geothermal is an indirect form of nuclear fission.

Glawen 5y ago

Yeah right. They drilled in Strasbourg, France, to get this "free" energy. When they entered production, the city was experiencing an earthquake every month, waking the city at night. After a magnitude 4 earthquake, they finally shut down the plant. A town in Germany is devastated also due to geothermal power: https://en.m.wikipedia.org/wiki/Staufen_im_Breisgau https://en.m.wikipedia.org/wiki/Staufen_im_Breisgau

eru 5y ago
Assuming this is a real problem, wouldn't you just put your geothermal power plant well outside of any city? Doesn't even have to be somewhere where there are no buildings. Just somewhere where hardening the few existing buildings against small earthquakes etc won't be too expensive.
- Fiahil 5y ago
  > Just somewhere where hardening the few existing buildings against small earthquakes etc won't be too expensive. So, expending twice on a bad idea ? Seriously, what do you think will happen ? And even it was technically possible, how do you insure a company like that ? Will the plant operator be responsible for the repairs and damages when they destabilize an entire region ?
  - eru 5y ago
    > So, expending twice on a bad idea ? Seriously, what do you think will happen ? What do you mean? A few really minor earthquakes are all that was reported by the comment I was replying to. So I'd assume more really minor earthquakes. > And even it was technically possible, how do you insure a company like that ? The usual way of paying an insurance company? > Will the plant operator be responsible for the repairs and damages when they destabilize an entire region ? Depends on the jurisdiction. But sure, you can make the plant operator responsible for that and responsible for having gigantic insurance coverage. (Just look at whatever liability people who operate dams have today. A breakage of a major dam would also devastate entire regions. So whatever arrangements are good enough for that use case are probably good enough here.)

imgabe 5y ago

How much energy is in the core of the Earth? What happens if we cooled the core to the point that it became solid? I’m guessing that would be bad, but is it something that’s not conceivably possible on any human timescale?

chii 5y ago
It would take quite a lot to cool the core.
ComradePhil 5y ago
We can pump heat into the core when it is hotter in the surface. So, it can also work as a battery.
- axiolite 5y ago
  > We can pump heat into the core when it is hotter in the surface. Were you expecting a massive meteor impact in the near future that the rest of us are unaware of? If not, exactly how were you planning to get enough heat at the surface of the Earth to warm-up the core?
  - ComradePhil 5y ago
    Do you think we drill to the very core to get thermal energy? Well, I have disappointing news for you: The earths radius is 6,371 km; for thermal plants, we dig like 5 km. While the core is 5000 degrees celcius, the point we dig to is more like 150. Concentrated solar power can generate 1000 degree celcius. If we pump this down when we have excess, the area remains hotter than it would otherwise be... letting us use it when the sun sets. This can also work through much longer timescales, like you could dump energy heat down in the summer and harvest it in the winter. The post I was replying to was worried about gradual loss of core heat. This will be minimized if we pump heat in.
pm90 5y ago
Not until humanity becomes a type 2 Civilization. Which seems like at least a 1000 years away.

a1371 5y ago

A lot of people like to talk about nuclear as a climate solution. Geothermal is the most gargantuous nuclear plant we can fathom, all we have to do is to extend a pipe and harvest it. Here is the thing, a lot of that tech is coming from oil and gas. An industry with a track record of leaving the land they enter in terrible shape. I think we have to start over with geothermal and look at it more like hydro electricity. We should harvest the electricity on the way down, not the way up. I wish I'd get rich enough one day to devote my life to this.

ComradePhil 5y ago
> We should harvest the electricity on the way down, not the way up. Could you please explain what you mean?
- tschwimmer 5y ago
  I have to assume GP means that we should extract the geothermal heat at the bottom of the well/borehole, not by bringing the oil back up to burn it.
  - a1371 5y ago
    No, I mean we should use the motion of the water, not its heat. Like in hydroelectricity where water spins a turbine instead we are using a steam generator like gas fired plants
    - manarth 5y ago
      A steam turbine essentially _does_ use the motion of the water. In conventional hydroelectricity, gravity causes the motion through the energy differential of the waters' height. In a steam turbine, the potential energy is from the high temperature of the water, and the energy input to rotate the turbine comes from the temperature differential of the steam cooling. In theory you could capture the hydroelectric energy of the water on its way down a 12 mile hole, but that gravitic potential energy is negligable compared to the energy difference between superheated steam and water.

russellbeattie 5y ago

I suggested an idea for a backyard geothermal generator in a comment a few months ago and got shut down because it would be too costly to drill the hole. But hey now! This microwave drill might do the trick! Hmm. Are magnetrons and gyrotrons the same thing? Probably not. So we can't rip apart an old microwave oven and start drilling holes out back just yet. Damn. https://news.ycombinator.com/item?id=27777665 https://news.ycombinator.com/item?id=27777665

TeeMassive 5y ago

I've always wondered, but geothermal plants are basically huge radiators. If Humanity taps into this energy in industrial scale for centuries, would we cool the planet's mantle and core enough to have repercussions on the magnetic field for example?

modeless 5y ago
20 km is 0.3% of the way to the center of the earth. It seems unlikely that anything we do there could affect the core in a meaningful way.

modeless 5y ago

Converting existing fossil fuel plants sounds awesome. But they haven't actually drilled any deep holes with this new technology yet, right? They're going to go from nothing to drilling almost twice as deep as the deepest hole ever drilled by humans, in four years?

jokethrowaway 5y ago

The comments on the article make me lose faith in humanity. Amazing technology though, this coupled with solar could really make people independent of centralised energy systems

lwouis 5y ago
Independence is a pipe-dream. You always depend on others and physical resources. If you install a solar panel to "become independent from centralized energy systems", you're moving from a dependence to established energy networks to another type of dependence. You now depend on people making, delivering, maintaining panels for you. As well as the batteries to store the energy. No-one can make or repair this take themselves. You just moved the dependence from one system to another. The current system is also battle-tested and mutualized. Outage see lots of people on deck to fix things. If your solar installation panel breaks it's your individual problem and it will quickly reveal just how dependent you actually are. The only way to be independent of other humans would be to live a lifestyle which requires only rudimentary knowledge, and the muscles of your body. Probably only hunter-gatherer. Anything beyond that means you rely on knowledge, skills, and muscles of other, and dependent on them for your life. Maybe you knew all this, but it may still be useful for other readers to realize since these days we hear a lot of prophets telling us how we should increase our independence by installing solar panels or wind turbines. And people don't think twice about where these come from, and who will maintain them.
- qiskit 5y ago
  > If you install a solar panel to "become independent from centralized energy systems", you're moving from a dependence to established energy networks to another type of dependence. You now depend on people making, delivering, maintaining panels for you. As well as the batteries to store the energy. Thank you. People claim they are independent because they are off-grid and using solar panels. But are they really? Solar panels last about 10 years and then what? Of course they are dependent on the grid that provides them the solar panels and batteries.

CyanLite4 5y ago

I wonder if you could optimize it a little further to get energy from both directions… Energy produced in the way up (heated water) and on the way down (gravity-Fed turbines)

Animats 5y ago

Microwave drilling. It's a known thing at small scale.[1] If it can be done at larger scale, it ought to have other applications. Doing it downhole at the end of a long pipe string is going to be much harder than doing it in a factory. So why isn't this an industrial machining process already, like plasma cutting? GA Drilling was pushing plasma drilling back in 2018.[2] They're still pushing it, but not making holes. The University of Minnesota was pushing electro-pulse boring in 2015.[3] Again, no deep holes. There's something called ThermoDrilling, which, despite the name, is more like a water jet cutter.[4] Successful projects are still using mechanical drilling.[5] So there are a lot of deep hole drilling approaches being studied. Anything that works would be used by the oil and gas industry, and if they're not trying it, one suspects it might not be working. [1] https://www.researchgate.net/publication/270653673_Microwave_Drilling_of_Materials https://www.researchgate.net/publication/270653673_Microwave... [2] https://www.gadrilling.com/ https://www.gadrilling.com/ [3] https://experts.umn.edu/en/publications/electro-pulse-boring-epb-novel-super-deep-drilling-technology-for https://experts.umn.edu/en/publications/electro-pulse-boring... [4] https://www.geodrillinginternational.com/deep-geothermal/news/1385347/thermodrill-an-innovative-drilling-system-for-deep-geothermal https://www.geodrillinginternational.com/deep-geothermal/new... [5] https://geothermalengineering.co.uk/united-downs/ https://geothermalengineering.co.uk/united-downs/

leoedin 5y ago
This could also have good use for ground source heat pumps - they're the most efficient, robust and consistent source of domestic heating we have, but require fairly deep (60m ish) boreholes. If digging could be quicker, easier or faster these heat pumps could be installed everywhere.
- hectormalot 5y ago
  I have one of those. The well is 170m deep. Took 2 guys about half a day to drill it, so that actually doesn’t seem excessive in terms of time required (mostly sand, no rock below my house).
  - NavinF 5y ago

ZeroGravitas 5y ago

This sounds like cool tech, and the re-use of the existing generation assets is clever, but just running costs of the steam part of an existing plant struggles to compete on a financial basis with wind turbines and solar PV so it'll probably only ever be a niche thing. Shared ground loops connected to heat pumps are a more boring tech with more potential to have a global scale impact.

erosenbe0 5y ago
You cut out the combustion stack and boiler here so it has to be much cheaper than fossil fuel turbine?
- ZeroGravitas 5y ago
  I wasn't even counting the combustion part, just the heat to steam to electricity part (common to coal and nuclear plants). I had assumed they would need to transfer the heat rather than pipe geothermal steam directly into the turbine, but either way, solar and wind is very cheap and hard to compete with. Even magical free energy connected to a steam turbine struggles when you do the sums, which is the baseline before you start including cost and risk from super deep drilling.
p1mrx 5y ago
Assuming that people commit to buying 24/7 carbon-free energy at any price, on-demand generation like geothermal will be quite valuable during the times when wind and solar are underperforming. So geothermal will mainly compete with nuclear and storage, not wind and solar.
- ZeroGravitas 5y ago
  Yep, and like nuclear, it has a high up front cost that needs to be amortized over near constant use to be viable which means it prices itself out of that role pretty quickly compared with say green ammonia fired peaker plants that mostly incur costs when actually used and also use the green energy being produced in large quantities.

cryptica 5y ago

I hope that investors did the math to ensure that the energy used to dig such a deep hole with microwaves doesn't end up consuming more energy than the hole will generate over its lifetime... Will the hole crack irreparably after a few months? Nowadays, there seems to be an epidemic of engineering neglect in terms of capital allocation. A lot of wealthy individuals who have the capital to invest in such projects do not seem to have the engineering mindset (or no longer do) to see through greenwashing BS. "It's all about the people" is BS. These days, there are charlatans everywhere and they seem to have monopolized all the billionaires.

re6fae5Wied5tha 5y ago
I can't imagine it takes more than a few circuits of water through the bore to recover all of the energy, the static column of water alone would contain a non-trivial fraction of the energy required to drill the bore after equilibrating.

dzhiurgis 5y ago

A few Lithuanian names there. They’ve apparently tried geothermal in Klaipeda but faced salt water which was hard to handle. Generally Eastern European cities with centralised heating are very suited for geothermal. Except they’ll loose all that sweet sweet kickback from Russian oil dealer.

WalterBright 5y ago

If you drill a hole deep enough, you'll be unable to prevent the hole from collapsing in on itself. I wonder how deep that would be.

kragen 5y ago
Conventionally you fill the hole with mud with the same density as the rock, avoiding this problem. You couldn’t drill into the inner core that way because it’s liquid, and maybe at some shallower depth you’d run out of candidate mud materials that will stay liquid at the relevant temperature, but given the right mud I think you could pass the Moho. So far, though, the problem is breaking drill strings.

imranhou 5y ago

Is there a chance that the hole creates a mini volcano that cannot be stopped?

erosenbe0 5y ago
One assumes well blowouts will be a serious problem, as with any energy extraction.
re6fae5Wied5tha 5y ago
This is actually the risk I came here to mention about deep bores. Bore first, build later, otherwise you may be the unlucky winner of a fluid formation trapped under a rigid formation in the local geology. https://theconversation.com/a-mud-volcano-has-been-erupting-for-ten-years-and-scientists-are-still-undecided-what-caused-it-80827 https://theconversation.com/a-mud-volcano-has-been-erupting-...

suction 5y ago

And every dance move is "The Robot" if you imagine an advanced enough robot...

grecy 5y ago

I can't help but wonder if this means we can drill our own private hot springs wherever we want...

bencollier49 5y ago

How much geothermal power would you need to extract to completely cool the core of the Earth?

themerone 5y ago
All of it.

z3t4 5y ago

If we do this in large enough scale, will the earth eventually cool down?

throwaway0332 5y ago

> True geothermal energy is truly green Reminder: few energy sources do not add heating to the atmosphere during the whole energy lifecycle! It's the ones that *subtract* energy from the environment in the first place: solar, wind, dams, tidal energy. Other sources (including geothermal, nuclear, oil ...), even if we could produce a 100% efficient power plant, are still extracting energy that would otherwise stayed "locked-in" somewhere. Keep in mind that virtually all electrical energy produced turns into heat released in the atmosphere.

alex_smart 5y ago
I think one relevant question is: how does that amount of energy compare to the energy that the earth is bombarded with by the sun anyways? If it is miniscule (say less than 1%) in comparison, will that have a significant impact on global warming? https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026 >A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use. So even if we get all of our current energy needs from these sources, that is less than 0.01% of the energy earth gets from the sun. Is that going to have a significant effect on the temperature of the earth?
andy_ppp 5y ago
Energy from heat is never discussed with climate change, only energy from the greenhouse effect. Do you know what percentage of each (roughly) human activity is causing?

FrankyHollywood 5y ago

Drilling is not the problem which stands in the way for using earth warmth. It is pollution of ground water, risk of earth quakes, transportation of the heat, local cool down and having to drill new wholes. In Europe we have tried, and tested with wholes up to 1km depth but it is not as ideal as one might think. Otherwise it would have been used on a large scale already.

giantg2 5y ago

In regards to the deeper drilling... wasn't there an article recently that the core is cooling faster than previously thought? Do we know how it could affect the earth if we are doing this at a large scale? Are we going to cause problems further down the road because we don't know enough.

twobitshifter 5y ago

I can’t find what the progress or results of the arpa-e project were either on the quais website or elsewhere. https://arpa-e.energy.gov/technologies/projects/millimeter-wave-technology-demonstration-geothermal-direct-energy-drilling https://arpa-e.energy.gov/technologies/projects/millimeter-w... The Altarock energy site is currently showing a 503. Altarock from Seattle won the arpa grant and were noted as an “affiliate” of Quais in the ieee article. https://spectrum.ieee.org/altarock-energy-melts-rock-with-millimeter-waves-for-geothermal-wells https://spectrum.ieee.org/altarock-energy-melts-rock-with-mi...

ineedasername 5y ago

Whenever the topic comes up, it always seems strange that going more than just a handful of mi/km down is an incredibly difficult task. Because it makes me realize-- or remember-- that the most life-hostile & technology-defying environments aren't in far off geographic locations or far out in space, they're a constant presence just under my feet. A shorter distance from me right now than I travel in my daily commute. That as space enthusiasts (rightfully) speculate or plan the future above our heads, there are incredible things going on beneath our feet at forces and temperatures that also produce very exotic materials and even the prospect of untapped clean energy just a short distance away from every single place in the planet. (Assuming that drilling down for geothermal power isn't horrible for the environment?) Just another example of how very little in the natural world is truly mundane and there are incredible things everywhere.

gumby 5y ago

> The problem is it has only been practical in volcanic regions or near the edges of tectonic plates, where cracks in the Earth's crust allow steam to form close to the surface like in Iceland or the geysers in California. Incredibly, California has managed to kill its geysers. Apparently when Geyserville was settled there were puffs of steam coming out all over the place. Now the geothermal plant there injects wastewater into the rock and then drives its turbine with the steam that comes back.

pharke 5y ago

If we converted all energy production to geothermal, would it be possible to significantly increase the cooling of the Earth's core? The flow from the Earth's core to the surface is estimated at 47±2 terawatts[0] The total energy supply for 2017 was 162,494 TWh[1] World energy demand is expected to grow 27% by 2040 Currently, heat escaping from the Earth accounts for only 0.03% of Earth's total energy budget at the surface which is dominated by the 173,000 TW contributed by solar radiation[0] What effect would it have if the vented heat were equal to the amount contributed by the sun? [0] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget [1] https://en.wikipedia.org/wiki/World_energy_supply_and_consumption https://en.wikipedia.org/wiki/World_energy_supply_and_consum...

originalvichy 5y ago
I can be wrong but that number sounds so low that it might mean the energy at the literal surface, in the same vein as how much solar heat energy reaches the planet’s surface. I assume that the number is vastly greater if you measure the heat 1km below sea level for example.
samatman 5y ago
The only mechanism we would have for significantly increasing the cooling of the Earth's core would involve heading the atmosphere well past the habitable band. Ultimately if heat isn't radiating from the atmosphere, it isn't leaving the planet.
ant6n 5y ago
The bigger question is whether we will heat up the surface top much, given that the energy would be produced by a heat engine. (I suppose you could build a heat engine by using the temperature differentials of different underground layers, although I've never seen that proposed)
RugnirViking 5y ago
surely there must be some numbers wrong here? How can the total energy supply be only just barely less than the entire amount of energy applied to the planet by solar radiation? Is it suggesting that covering the entire surface of earth with 100% efficient solar panels would just barely cover 2017's power supply? Edit: ah I see, world energy is in terawatt hours for an entire year, wheras planetary solar energy is terawatts in a single hour

throwaway9870 5y ago

You just don't "use" heat to make electricity. You need some sort of heat engine running a cycle. All those require temperature differential. This is basic thermodynamics and isn't going to change with new technology. This temp differential is what is required to extract useful energy. So I don't understand why they talk about material at a certain temp having energy compared to oil. If we lived on a planet that is uniformly 1000 deg F, it wouldn't help us because we don't have a temp differential to convert thermal energy to electric. Nowhere in the article did I see them mention temp differential and where they are going to dump the waste heat? Nuclear plants get crapped on because they dump heat into adjacent water bodies, how is this different?

sidewndr46 5y ago
Your point is well made. If all it took was heat, then climate change would probably be the best thing ever. More heat captured from the sun would give us more energy.
- hedora 5y ago
  Open challenge: Getting an elected US politician to seriously propose a space heat sink as a solution to climate change. There were some people seriously proposing big convection tubes that'd bootstrap columns of hot air, then passively pull surface air into the upper atmosphere. I can't find a link, but those wouldn't get to low earth orbit, so not a "space" technology.
  - sidewndr46 5y ago
    I've heard of launching some large mirrors into orbit, or a bunch of small mirrors that can link together in orbit. Then you use them to reflect some sunlight off into space. I have no idea how practical this is. The bigger concern would be if something goes wrong, you need to make the mirrors deorbit quickly.
    - hedora 5y ago
      You could set it so that some of the mirrors formed a parabolic collector and heated a molten salt column, etc on the surface. That'd have the same net effect as the giant heat sink (energy production from a heat engine, net negative flow of energy to the surface). Wasn't there a city builder that'd let you build such a thing, where it would sometimes lose calibration and burn a swath of the city to the ground?

rvalue 5y ago

and suffer the fate of krypton? sorry, I couldn't read the article without solving the question of energy cycle in my mind. renewable sources like solar, wind are kind of taking energy from outside, so in case of geo-thermal, if we keep using that, there is nothing thats balancing the equation.

stareatgoats 5y ago
You are right, this tech would cause the core to lose temperature at a slightly higher rate than otherwise. At the moment the earths core is cooling at the rate of 0.1 °C per million years from the current temperature of about 5,100 °C, interspersed with periods where the temperature loss is stopped or reversed because of gravity forces [0]. But any conceivable number of deep geothermic wells would not affect that rate in any measurable way. [0] https://en.wikipedia.org/wiki/Earth's_inner_core https://en.wikipedia.org/wiki/Earth's_inner_core

holoduke 5y ago

Wonder if one day we find out that thermal energy is cooling down earth too much. Reducing magnetic field around the earth which causes a huge reduction of our ozone layer and eventually even the entire atmosphere.

FlyNestor 5y ago

Hope this new technology will have success. You never know it can be the next Theranos.

charles_f 5y ago

Somewhat related, I used to think that residential geothermal heating was basically harvesting the steaming heat from the soil to your house. I figured that would require seating on a volcano. In fact it's using a heat pump, and liquid circulating in pipes burried a few feet underground to act as a thermal sink, to either heat or cool down a house. This works well because the temperature in the ground doesn't fluctuate much past 3ft. Pretty neat, and does not require to go down miles (though it's moving energy to/from ground rather than harvesting it and you still need an energy source for the pump)

thescriptkiddie 5y ago
A ground-source heat pump is technically not geothermal, because the bulk of the heat comes not from the earth but from the sun. You are basically using the soil as an enormous thermal battery which charges up in the summer and stays warm (relative to the air) through the winter. Real geothermal power plants are actually indirectly harvesting heat from the molten inner layers of the earth, which is mostly leftover from the the formation of the planet.

hsnewman 5y ago

Thanks, captain obvious.

theptip 5y ago

The idea of drilling deep geothermal to repurpose existing fossil plants is an elegant one. I imagine others have thought of this before, but it was new to me. Being able to take over the existing equipment (turbines, power transmission connections) seems appealing. Of course, it all depends on how expensive the drilling process is vs. the existing capital asset in the turbines, but maybe you could hit a price point where the repurposed geothermal plant is way cheaper than new solar / gas builds in the 2030s? This would be a transitional tailwind, just when we need it. Down the road, these plants would become more expensive because you'd also need to build new turbines/transmission lines. And at that time maybe solar or fusion is a cheaper solution (or not, who knows). But this could really help with the transition away from fossil fuels, if it was delivered next decade or two. A question - does deep drilling like this have any downsides, as fracking does? I'm guessing it's less bad since you're not pushing pressurized fluid into the bedrock, instead you're just making a pipe that contains the water.

fly-guy 5y ago
ENergy conversion equipment can't easily be re-purposed for geothermal. The temperatures are usually much lower, and the working fluids are often hydrocarbons instead of steam.
- theptip 5y ago
  Quaise seems to think it's possible: > “What we intend to do is go to existing power plants—it could be a coal power plant, it could be a gas power plant, any of the thousands of fossil-fired power plants that exists in the United States and around the world—and we will propose to them to create a small geothermal field around them, which is matched to the turbine specification of the power plant. What comes out of the ground is steam that feeds into the turbine, and the rest is what they’ve always done. The turbine creates electricity. The plant is already connected to the grid,” https://www.powermag.com/a-game-changing-vision-for-geothermal-energy/#:~:text=%E2%80%9CWhat%20we%20intend,to%20the%20grid%2C https://www.powermag.com/a-game-changing-vision-for-geotherm... Could just be marketing fluff; I'm not an expert here. But don't coal plants exclusively use steam turbines? Edit: Seems that lots of energy in the US comes from steam turbines: https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php#:~:text=Steam%20turbines%20are%20used%20to%20generate%20the%20majority%20of%20the%20world%E2%80%99s%20electricity%20and%20they%20accounted%20for%20about%2044%25%20of%20U.S.%20electricity%20generation%20in%202020 https://www.eia.gov/energyexplained/electricity/how-electric....

tiku 5y ago

I always wondered why we didn't have laser drills yet, but microwave drills sound way cooler.

perlgeek 5y ago
Why not make it microwave lasers? :-)

abeppu 5y ago

> The microwave beam is hot enough to evaporate rock, and the vaporized rock is pumped back to the surface. Is this part harder than it sounds? Do you need to keep it as hot vapor until it gets to the surface? What do you do with it then? Presumably a 12 mile column of rock turns into a whole lot of vapor. Is it toxic? When vaporized rock cools, does it become just sand, or are there interesting/concerning chemicals left over? As a lay person, I'm never sure when I read about new tech to address environmental issues whether we're creating a new problem. We've spent generations aggressively pumping carbon out of the ground and into the atmosphere. Would a move towards rock-vaporizing drilling just mean aggressively pumping a bunch of silicon, iron, etc out of the ground and into the atmosphere?

perlgeek 5y ago
I don't really know, so take my answer with a grain of salt, but my lay understanding of chemistry and physics tells me: * Typically vaporized solids a fine powder they cools down in air, or otherwise deposit on cool surfaces * Fine rock powder could be hazard to lungs, but it shouldn't be too hard filter it out of the air that leaves the hole * Some rock materials contain sulfates or phosphates; letting those escape into the atmosphere in large quantities would be bad; but you could always let it recombine with the rest of the evaporated rock, rendering it inert. Such a process wouldn't be 100%, so this is something worth looking out for. Most wealthy countries require an environmental impact assessment before any such operation, so there's hope such things would be caught before they become a big problem.

doikor 5y ago

There is a project for deep geothermal heat in Finland. They specifically chose to do it here as it is one of the worst places to do it (have to drill really deep to get anything useful also the first 4 to 5km is just pure bedrock instead of some softer material). So they ended up making 6.4km deep holes where they got 121 degree (celcius) water. Once pumped up to ground level it cools down to 110 degrees but it is more then hot enough for district heating. The original plan was to got 9km deep but it was already hot enough at 6.4km so they stopped there to save money. https://www.st1.com/geothermal-heat https://www.st1.com/geothermal-heat

sandos 5y ago

Is this really, really renewable? I thought the heat down there was stored from before and will eventually peter out... We might all be dead by then but hey... not renewable!

4khilles 5y ago
The sun will run out of hydrogen in ~5 billion years, solar isn't renewable either!

empressplay 5y ago

War is the mother of innovation

fallingfrog 5y ago

They can keep the microwave beam that tightly focused that the energy goes into making the hole deeper and not wider when the bottom is a target 6 inches across and 12 miles down? Wouldn’t it spread out and just absorb into the walls? This feels wildly implausible.

mvkel 5y ago

The problem with geothermal is there's no easy way to know where the "hot spots" are without drilling, which comes at a high cost.

joshspankit 5y ago

What would happen if literally everyone switched to geothermal tomorrow? Would we affect the core of the earth by extracting it’s heat at our current global usage? At double or triple our usage as the world gorges itself on this new source of clean power?