Digging 10 miles underground could yield enough geothermal energy to power Earth(interestingengineering.com)
interestingengineering.com
Digging 10 miles underground could yield enough geothermal energy to power Earth
https://interestingengineering.com/innovation/digging-10-miles-geothermal-energy
28 comments
Worked on a core drill rig that that did 2200m core drilling, worked a number of holes from 100-2200m on a few different types of surface rigs. Stuff gets weird when you get deep >1500m. Runs take ages, bit changes can take an entire shift. The structures in the rock can come out looking like a picture in space (black base littered with color). Hitting 10 miles (16km) would be epic. Something like 100 ton rod string hanging at BQ size. Insane.
Reminds me of the hole the soviets dug back in the 80s: https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
"To scientists, one of the more fascinating findings to emerge from this well is that no transition from granite to basalt was found at the depth of about seven kilometers (4.3 mi), where the velocity of seismic waves has a discontinuity. Instead, the change in the seismic wave velocity is caused by a metamorphic transition in the granite rock. In addition, the rock at that depth had been thoroughly fractured and was saturated with water, which was surprising. This water, unlike surface water, must have come from deep-crust minerals and had been unable to reach the surface because of a layer of impermeable rock"
"To scientists, one of the more fascinating findings to emerge from this well is that no transition from granite to basalt was found at the depth of about seven kilometers (4.3 mi), where the velocity of seismic waves has a discontinuity. Instead, the change in the seismic wave velocity is caused by a metamorphic transition in the granite rock. In addition, the rock at that depth had been thoroughly fractured and was saturated with water, which was surprising. This water, unlike surface water, must have come from deep-crust minerals and had been unable to reach the surface because of a layer of impermeable rock"
It's a fascinating project and a real shame funding was cut off. The deep borehole in Mexico was also stopped due to lack of funding.
Maybe they can use global warming dollars to renew these deep borehole projects around the world, as I suspect there is new geological science to be discovered as observations appear to deviate from theory:
"Because of higher-than-expected temperatures at this depth and location, 180 °C (356 °F) instead of the expected 100 °C (212 °F), drilling deeper was deemed unfeasible. The unexpected decrease in density, the greater porosity, and the unexpectedly high temperatures caused the rock to behave somewhat like a plastic, making drilling nearly impossible"
Maybe they can use global warming dollars to renew these deep borehole projects around the world, as I suspect there is new geological science to be discovered as observations appear to deviate from theory:
"Because of higher-than-expected temperatures at this depth and location, 180 °C (356 °F) instead of the expected 100 °C (212 °F), drilling deeper was deemed unfeasible. The unexpected decrease in density, the greater porosity, and the unexpectedly high temperatures caused the rock to behave somewhat like a plastic, making drilling nearly impossible"
That's strange, wouldn't a plastic be much easier to drill into? Maybe it required a different kind of drill head that they had no way of getting down there within budget?
The problem is the pressure. Even steel gets soft when it gets hot enough and with the pressure its like trying to push folded toilet paper through cake dough.
If it's already that hot, why do they even need to dig any deeper?
Why not extract the heat from there and use it to create power?
Why not extract the heat from there and use it to create power?
Yeah, that's exactly what people do already.
And secondly it doesn't take an extremely high temperature to reduce steel's strength. Many steels starts losing strength at 200°C, cast iron at 400°C. Source: https://www.engineeringtoolbox.com/metal-temperature-strengt...
This doesn't mean that the drill is soft but at extreme depth extreme hardness is required.
And secondly it doesn't take an extremely high temperature to reduce steel's strength. Many steels starts losing strength at 200°C, cast iron at 400°C. Source: https://www.engineeringtoolbox.com/metal-temperature-strengt...
This doesn't mean that the drill is soft but at extreme depth extreme hardness is required.
So why is that not enough?
What would digging even deeper get us?
What would digging even deeper get us?
I don't know. I am afraid that article is bullshit. So it doesn't make sense to give an answer to your question.
This aside, let me give some examples about geothermy. In Iceland and in New Zealand it is possible to get hot water from the ground without deep drillings. In Switzerland there was a failed project about geothermy, because the drill down to the granite bedrock at a depth of about 2700 m and deeper caused an earthquake. People in Basel are very sensitive because it was a location of an huge earthquake 1356.
In other words, we don't need to drill so deep at all. YAGNI.
This aside, let me give some examples about geothermy. In Iceland and in New Zealand it is possible to get hot water from the ground without deep drillings. In Switzerland there was a failed project about geothermy, because the drill down to the granite bedrock at a depth of about 2700 m and deeper caused an earthquake. People in Basel are very sensitive because it was a location of an huge earthquake 1356.
In other words, we don't need to drill so deep at all. YAGNI.
You need about 500C for steam turbines to be good, and the relatively weak heat won't last.
I guess you could use the heat as you go to try to cool it enough to keep drilling over a few years.
I guess you could use the heat as you go to try to cool it enough to keep drilling over a few years.
Another idea might be to have solar panels or wind turbines up top and geothermal below. Both could use molten salt storage, from which energy is generated on demand.
This way, any heat generated from geothermal would not be wasted.
It's just a matter of whether the economics of drilling and maintaining the bore hole would be worth it.
This way, any heat generated from geothermal would not be wasted.
It's just a matter of whether the economics of drilling and maintaining the bore hole would be worth it.
That's known as the Mohorovičić discontinuity, AKA the moho, to geologists.
Makes me wonder if there can be evidence for the Theia Impact hypothesis found at that depth
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The longest wells are already close to 10 miles, but it is mostly horizontal. My understanding is going deep you eventually hit hot rock which has a clay like texture and isn’t amenable to drilling.
Core drilling is quite different from well drilling which would be used in this case.
Core drilling is quite different from well drilling which would be used in this case.
Yes, and it's hot enough that your drill starts heating up and getting the same texture if you're not cooling it aggressively, which is hard to do so deep down.
Can nukes have their explosion shaped to be directly downward to dig this far?
[super layman speculation]
https://en.m.wikipedia.org/wiki/Nuclear_shaped_charge
so it's possible, though questions/problems arise such as: the cavity created by the explosion has a high chance of collapsing, the energy might trigger earthquakes, etc.
though smaller scale shaped charges "might" work to push rock out of the way, if the well segments can be advanced down safely into the created space.
https://en.m.wikipedia.org/wiki/Nuclear_shaped_charge
so it's possible, though questions/problems arise such as: the cavity created by the explosion has a high chance of collapsing, the energy might trigger earthquakes, etc.
though smaller scale shaped charges "might" work to push rock out of the way, if the well segments can be advanced down safely into the created space.
I'm gonna say no. You'd be going up against the compressive resistance of the ground. At depth where the pressure is already high, you won't be able to compress the ground much further even with the extreme force of a nuke, and most of the compression that you do achieve will just bounce back a moment after.
At shallow depths it is possible for matter to be pressed to the side, because in addition to being lower pressure and more compressible, matter can be displaced sidewards and up. I imagine shaping the nuke will make a differently-shaped cavern, but still just a cavern.
At shallow depths it is possible for matter to be pressed to the side, because in addition to being lower pressure and more compressible, matter can be displaced sidewards and up. I imagine shaping the nuke will make a differently-shaped cavern, but still just a cavern.
The nature of the fireball means you can't really use any type of physical structure to shape it... though I guess multiple miles of rock would work too, but it won't be in the desired direction[1]
[1]https://en.m.wikipedia.org/wiki/Operation_Plumbbob#Missing_s...
[1]https://en.m.wikipedia.org/wiki/Operation_Plumbbob#Missing_s...
Look up Casaba Howitzer. The blast can be shaped to a fair degree. It's not going to be useful for drilling a hole, though.
Have any pictures to show?
Nah no photos allowed as it was gold core work. You basically see if a mine is going to strike gold over next few years before everyone else does (think stock market performance impacts). Too much risk of data exfiltration given they had enough of a problem with word of mouth.
Why would the benefit be "stock market performance impacts" rather than just not digging a gold mine at all if the results came back negative?
Because these results can show more information than just a single bit?
The result might not just show “not worth digging” vs “worth digging”, but something like “the gold will flow for 4 years and then only trickle for 2” vs “the gold will flow for 8 years and then nothing”.
The result might not just show “not worth digging” vs “worth digging”, but something like “the gold will flow for 4 years and then only trickle for 2” vs “the gold will flow for 8 years and then nothing”.
You wouldn't be able to know how many years exactly from the core drilling visuals, for that you'd need to assay the cores for the grades, build a mining block model and then develop a mining plan from that. It's more of a qualitative "oh dam they've struck gold a lot of it" sort of thing that would move markets. Disclosures to markets in mining need to be done publically and with proper backing of data, legacy of BreX salting their core samples and reporting the motherload of gold mines.
This ^^^ We weren't drilling core for todays mining. We were sampling to see if the mine was viable years ahead and where underground would be directed over the coming months. The deeper you are or the further you are from the pit or underground path the further into the mines future you are looking essentially.
Edit: Also these are big publicly traded companies, drill reports get added onto forecasts for mine productivity which affects stock price projections & profit projections.
Edit: Also these are big publicly traded companies, drill reports get added onto forecasts for mine productivity which affects stock price projections & profit projections.
What do these bits look like? How wide are they? How does the drilling work, are they hollow and the material goes in the middle, which you then pull up every now and then? Do they come in sections (how long) and you just keep putting in more?
Sorry for many questions just can't find much info on actual field truth (just generic info on theory of operation).
Sorry for many questions just can't find much info on actual field truth (just generic info on theory of operation).
So we drilled core for gold. There are two main types of drilling RC and diamond core. RC is like a pneumatic hammer system i didnt work with those so cant say much about them (they recover a dust pile as their sample type, diamond core pulls out preferably a long cylinder core sample that has orientation marked on it (e.g. north).
Diamond core drilling tho is basically a cylinder shaped drill bit attached to a hardened drill rod that is attached to a rod string (groups of 3m pipes). Everything is basically done in 3m lengths, mostly for transport reasons. When your drilling you work with the rods in bundles of 3 so 9m lengths. I worked mostly on UDR 1200's and a prototype surface rig that there were like...3 built? partnership between a few big companies. That rig was the one that could do (estimated) up to 3000m or so. Deepest I worked on was 2200m. Drill bit sizes if your interested in looking them up that we worked with are BQ,NQ,HQ,PQ. So external diameters ranging from 60mm with bq (core size of 36.5mm) to PQ @ 122mm ext. and 85 ID. We worked all manual by hand so PQ with a drill barrel weighing like 50kg was our limit. Shaking core from 3m HQ drill rods nearly broke me the first time I did it.
The drill barrels have a inner tube that is the core holder/lifter that hangs like a few mm from the spinning bit at all times while drilling, these are 6m long. After you have drilled 3m, you clamp the rod string so its hanging from the drill rig and add 3m until you have preferably 6m drilled. Drilling stops, you pull back on a wireline that is holding the core tube to engage the internal clamps on it and haul up your 6m of core. A empty tube gets sent back down, you add another 3m rod to the string and repeat the process. While this happens the full core tube is orientation marked, shaken out and cleaned and re-assembled as it comes out of the hole in core trays. ^^^^ Everything above is if things go to plan. Rough ground, broken bits, hard ground, loss of water return all kinds of things can cause problems and make runs stop, go short, loose rods, drop core, require bit changes, cause equipment to overload and break so on. Been a few years since I did it but I do kind of miss the work.
https://www.youtube.com/watch?v=DUMftmjpdNg This is a video of after a bit change. they are pushing rods back down the hole to hit the point where drilling stopped. They are moving real slow. 111 rods roughly to 1000m. Worst shift I had was 16 ton of rods moved. >1000m down, started shift pulling rods for a bit change, bit snapped a tooth after we got it back down in under 5m of cutting and had to come straight back out. Hell of a night. If your lucky you have 3 to a rig (driller and two offsiders) if your unlucky its just 2 on a rig. No breaks. You eat while you drill.
https://www.youtube.com/watch?v=VF3_TqN6AQA This video also covers the whole basics pretty well.
Diamond core drilling tho is basically a cylinder shaped drill bit attached to a hardened drill rod that is attached to a rod string (groups of 3m pipes). Everything is basically done in 3m lengths, mostly for transport reasons. When your drilling you work with the rods in bundles of 3 so 9m lengths. I worked mostly on UDR 1200's and a prototype surface rig that there were like...3 built? partnership between a few big companies. That rig was the one that could do (estimated) up to 3000m or so. Deepest I worked on was 2200m. Drill bit sizes if your interested in looking them up that we worked with are BQ,NQ,HQ,PQ. So external diameters ranging from 60mm with bq (core size of 36.5mm) to PQ @ 122mm ext. and 85 ID. We worked all manual by hand so PQ with a drill barrel weighing like 50kg was our limit. Shaking core from 3m HQ drill rods nearly broke me the first time I did it.
The drill barrels have a inner tube that is the core holder/lifter that hangs like a few mm from the spinning bit at all times while drilling, these are 6m long. After you have drilled 3m, you clamp the rod string so its hanging from the drill rig and add 3m until you have preferably 6m drilled. Drilling stops, you pull back on a wireline that is holding the core tube to engage the internal clamps on it and haul up your 6m of core. A empty tube gets sent back down, you add another 3m rod to the string and repeat the process. While this happens the full core tube is orientation marked, shaken out and cleaned and re-assembled as it comes out of the hole in core trays. ^^^^ Everything above is if things go to plan. Rough ground, broken bits, hard ground, loss of water return all kinds of things can cause problems and make runs stop, go short, loose rods, drop core, require bit changes, cause equipment to overload and break so on. Been a few years since I did it but I do kind of miss the work.
https://www.youtube.com/watch?v=DUMftmjpdNg This is a video of after a bit change. they are pushing rods back down the hole to hit the point where drilling stopped. They are moving real slow. 111 rods roughly to 1000m. Worst shift I had was 16 ton of rods moved. >1000m down, started shift pulling rods for a bit change, bit snapped a tooth after we got it back down in under 5m of cutting and had to come straight back out. Hell of a night. If your lucky you have 3 to a rig (driller and two offsiders) if your unlucky its just 2 on a rig. No breaks. You eat while you drill.
https://www.youtube.com/watch?v=VF3_TqN6AQA This video also covers the whole basics pretty well.
Dam, didn't think I'd see another mining person on hackernews. Exploration geology that far down is wild. Was it core sampling all the way from grade or only in mineralized zones?
Core sampling the whole way. Outskirts of jundee at wiluna. Punched a few holes down the side of the pit while I was there and the deep holes were for underground to work out where they were going. Most target zones 800-1200. I got lucky as the drillers I offsided with were absolute guns so we got the hard stuff. Best day we cracked >100m in our 12 hours and cross shift got 80m. 22mins was out fastest 6m off memory. That was shallow work tho, deep holes can take 45m just to pull a core tube.
I don't drill any more but do kind of miss the work.
I don't drill any more but do kind of miss the work.
Huh, I just drove the canning, I was in wiluna two weeks ago!
Your comments are opening up a new world for me. Thank you.
The drilling fluid/mud is pumped down the center of the string and flows back up the sides of the bore hole. The material removed comes up with the drilling fluid.
The drill string is a chain of threaded pipes.
There is tons of good information online, just search for oil well drilling on YouTube.
The drill string is a chain of threaded pipes.
There is tons of good information online, just search for oil well drilling on YouTube.
Geez https://amcmud.com/drilling-fluids/ if you want to look into some of the fluids/chems used in drilling.
This stuff is nuts, https://amcmud.com/product/amc-cr-650/ Have sent pallets of the stuff down hole. Few 500ml scoops of that and you can turn 5000l of water into some crazy thick mud for bringing up heavy cuttings. Worst experience tho copping a face full of dust when dosing it tho, gets in your eyes. Takes a ridiculous amount of water to wash past the thickening point and get it out.
This stuff is nuts, https://amcmud.com/product/amc-cr-650/ Have sent pallets of the stuff down hole. Few 500ml scoops of that and you can turn 5000l of water into some crazy thick mud for bringing up heavy cuttings. Worst experience tho copping a face full of dust when dosing it tho, gets in your eyes. Takes a ridiculous amount of water to wash past the thickening point and get it out.
I once had the task of measuring powdered dye for industrial soap. A coworker told me to make sure and tamp down the can. Turns out tamping the can kicks up just enough dust that I had blue snot for a week. Not an OSHA approved practical joke, but funny nonetheless.
Many are keen to point out that we live in proximity of a giant fusion
reactor and ought to be smart enough to harness its output.
But it took me a long time to appreciate something odder; We're living on a giant fission reactor [1]. The Earth's core isn't hot because it just hasn't cooled down in the icy void of space. It's actively producing heat. Our gravity acts upon the heavy elements, which sink through the molten iron and silicon, to the core, where they become fissile.
[1] https://blogs.scientificamerican.com/observations/nuclear-fi...
But it took me a long time to appreciate something odder; We're living on a giant fission reactor [1]. The Earth's core isn't hot because it just hasn't cooled down in the icy void of space. It's actively producing heat. Our gravity acts upon the heavy elements, which sink through the molten iron and silicon, to the core, where they become fissile.
[1] https://blogs.scientificamerican.com/observations/nuclear-fi...
Not a fission reactor. Just a radiothermal generator. It's not critical.
This article doesn't say anything surprising; the news is that these guys calculated how much heat is produced.
This article doesn't say anything surprising; the news is that these guys calculated how much heat is produced.
The news here, specifically, is that:
> Enter Quaise, which “is developing technology to blast rock with microwaves to potentially drill the deepest holes on Earth.
ie. there's a new, untried at extremes, bore drilling technique.
The calculation of heat production from earths core isn't new here, and nor, sadly, is any demonstration of a bore hole at a 10 mile depth.
They do acknowledge the deepest convential borehole so far was 7.6 mile (at some considerable effort at no small expense).
> Enter Quaise, which “is developing technology to blast rock with microwaves to potentially drill the deepest holes on Earth.
ie. there's a new, untried at extremes, bore drilling technique.
The calculation of heat production from earths core isn't new here, and nor, sadly, is any demonstration of a bore hole at a 10 mile depth.
They do acknowledge the deepest convential borehole so far was 7.6 mile (at some considerable effort at no small expense).
Ok I just read a bit more and apparently there are some fringe geophysicists who think it really is more like a reactor. I didn't know that.
There were actual "natural" fission reactors in the crust in central Africa some time ago[1] .. the broader region provided the bulk of the ore for the Cold War production of weapons grade ore.
[1] https://en.wikipedia.org/wiki/Oklo_Mine
[1] https://en.wikipedia.org/wiki/Oklo_Mine
Nature used up the best ore billions of years ago. We did get radiation-resistant microbes in exchange.
When I asked a physicist about this, he said it's mostly conjecture. You can't really prove it because we can't actually visit the Earth's core.
Yes, I'm aware how the neutrino velocity measurement supposedly confirms it. But I don't think the scientific community has accepted it at large.
Yes, I'm aware how the neutrino velocity measurement supposedly confirms it. But I don't think the scientific community has accepted it at large.
Radiothermal heating of planetary cores is established scientific fact. It's not a fission reactor because there's no chain reaction, just a lot of unstable elements in one place. Some details are controversial, but not the basics. (I have a geochemistry PhD)
Ok I just read a bit more and apparently there are some fringe geophysicists who think it really is more like a reactor. I didn't know that.
Yes, I think that is the where the debate is over the exact nature of things. Fission happens spontaneously, even the bismuth in Pepto Bismol has a bit of a fission going on, slowly decaying into thallium.
²⁰⁹Bi decay to ²⁰⁵Tl is alpha decay — the bismuth nucleus splits into an alpha particle (helium) and a thallium nucleus. I think you’d be hard pressed to find a nuclear physicist or engineer who calls that “fission”.
Here’s the Wikipedia article on fission. It’s a rather different process:
https://en.m.wikipedia.org/wiki/Nuclear_fission
Here’s the Wikipedia article on fission. It’s a rather different process:
https://en.m.wikipedia.org/wiki/Nuclear_fission
Can you link to what you are reading? I am a nuclear engineer, I suspect they are using a very loose definition of critical, one that would imply the entire universe itself is critical.
Maybe the fault is with me for using the word "reactor" a bit loosely.
I don't think anyone knows for sure what is going on down there.
My theory is that it's both critical and quiescent, with a violent dynamic at play. Gravity will concentrate the heaviest and least stable elements as you'd expect. As that happens pockets of dense matter in close neutron proximity will approach critical and heat billions of tons of matter which then convects outwards, dispersing the mixture. Think of a lava lamp.
I don't think anyone knows for sure what is going on down there.
My theory is that it's both critical and quiescent, with a violent dynamic at play. Gravity will concentrate the heaviest and least stable elements as you'd expect. As that happens pockets of dense matter in close neutron proximity will approach critical and heat billions of tons of matter which then convects outwards, dispersing the mixture. Think of a lava lamp.
Geochemists say uranium concentrates in the crust, for chemical reasons -- which is, in fact, where we find it.
are there estimates for how much heat is produced this way? any other way? (solar magnetic field interaction?) how much is the residual heat dissipation?
edit: ah, just read the title of the link posted in the top level comment. apparently it's "half of the heat" :)
edit: ah, just read the title of the link posted in the top level comment. apparently it's "half of the heat" :)
Yes. Alpha decay in particular is also the source of essentially all helium on earth, and the reason helium is captured from gas wells.
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I wonder how they will keep the waveguide free of contaminants and >1/10 wavelength irregularities that dissipate power over such a long transmission line relative to wavelength. They're starting from only 10kW from a single gryotron but absolute power isn't the real issue. They can always just incoherently combine many since it's not for communications but even doubling the power twice isn't going to get you past the number of 3dB (half power) losses you'd get with an improvised borehole mm-waveguide 10km down.
The extremely long low loss underground mm-wave waveguide would seem to be their first problem to solve.
Edit: https://publications.mygeoenergynow.org/grc/1034509.pdf is okay and on page 5 of 16 in Fig 2 you can see how they propose using purge gas down the waveguide segments to keep it clean.
The extremely long low loss underground mm-wave waveguide would seem to be their first problem to solve.
Edit: https://publications.mygeoenergynow.org/grc/1034509.pdf is okay and on page 5 of 16 in Fig 2 you can see how they propose using purge gas down the waveguide segments to keep it clean.
I assume they'd have a drilling pipe down which the mm waves would be directed. It would also carry down gas to blow the recondensed rock dust back up. The inner surfaces of the pipe segments would presumably be lined with a smooth, very conductive material.
This is basically the plot of early Soviet hard sci-fi novel "Победители недр" (1937) [0] by Grigory Adamov. A few intrepid scientists go build a thermal power station deep below the surface in a specially designed subterranean vessel, and somehow a young pioneer sneaks on board with them, eventually saving them all.
[0]: https://archive.org/details/pobediteli_nedr
[0]: https://archive.org/details/pobediteli_nedr
Geothermal is not an easy solution. Just drilling deep enough doesn't begin to address the environmental and engineering issues involve. Perhaps these issues will be resolved. I hope so.
Err...care to explain? I was under the impression that the only engineering issue with deep geothermal was precisely to drill deep enough.
Once you've done that, the rest is pretty straightforward: boil water to run a turbine. Actually I'm 100% sure people are talking about converting coal plants in place with deep geothermal.
Also,you put back the water you pump up, so it's literally a closed loop. What environmental issues are you talking about? The mud?
Once you've done that, the rest is pretty straightforward: boil water to run a turbine. Actually I'm 100% sure people are talking about converting coal plants in place with deep geothermal.
Also,you put back the water you pump up, so it's literally a closed loop. What environmental issues are you talking about? The mud?
Former exploration geologist here.
Drilling that deep is not easy. Directional drilling equipment is very expensive, and heat + pressure take a toll very quickly on such equipment. Directionality is important as boreholes are rarely straight an it is entirely possible to drill a borehole in a U shape accidentally. Drilling requires high pressure pumps to clear the face of the drill bit, and the cut material must be returned out of hole. That's one hell of a compressor or mud pump. Below a certain depth rock behaviour changes from brittle deformation toward more plastic (and explosive) deformation, to eventually plastic deformation entirely. Groundwater pressures can collapse holes. Deformation can collapse holes. The rock grinds back at drilling gear. Equipment can become stuck and difficult to dislodge. Holes eventually collapse and partially close on their own, requiring casing of the hole. To case, drill a section, retrieve gear from down hole, slide casing in, replace Drilling gear, repeat for each length of casing. It can be quite different per hole, and per rig setup. Some rig setups permit casing in place (this is more a drillers specialist area than my own).
Then, there's the issue of keeping the hole open long term. Hydrothermal activity tends to dissolve minerals in water. Minerals tend to crystallise out inside boreholes and pipes over time, like hard water in water pipes in rural areas, constricting flow.
What is being proposed is difficult and requires an extreme amount of maintenance through its life cycle.
Drilling that deep is not easy. Directional drilling equipment is very expensive, and heat + pressure take a toll very quickly on such equipment. Directionality is important as boreholes are rarely straight an it is entirely possible to drill a borehole in a U shape accidentally. Drilling requires high pressure pumps to clear the face of the drill bit, and the cut material must be returned out of hole. That's one hell of a compressor or mud pump. Below a certain depth rock behaviour changes from brittle deformation toward more plastic (and explosive) deformation, to eventually plastic deformation entirely. Groundwater pressures can collapse holes. Deformation can collapse holes. The rock grinds back at drilling gear. Equipment can become stuck and difficult to dislodge. Holes eventually collapse and partially close on their own, requiring casing of the hole. To case, drill a section, retrieve gear from down hole, slide casing in, replace Drilling gear, repeat for each length of casing. It can be quite different per hole, and per rig setup. Some rig setups permit casing in place (this is more a drillers specialist area than my own).
Then, there's the issue of keeping the hole open long term. Hydrothermal activity tends to dissolve minerals in water. Minerals tend to crystallise out inside boreholes and pipes over time, like hard water in water pipes in rural areas, constricting flow.
What is being proposed is difficult and requires an extreme amount of maintenance through its life cycle.
While all that is true the original article concerns using high intensity microwaves to drill, with an unbalanced purge gas. One of the advantages of this is the potential to create a glass casement as you drill. I'm not in the industry but it's a neat paper and your comment reads like you're simply unfamiliar with what they're proposing, ambitious as it is.
That’s because what they are proposing is untried fantasy at this point, and he’s talking about proven field reality.
MIT has verified the basics concepts at lower power levels. So while there's still uncertainty and risk here, it's wrong to say it's totally untested. It's trying to make the jump from lab demonstration to commercial viability, which is exactly what you'd expect a research project like this to be doing.
There is a vast difference between ‘verified at low power levels in theory’ and ‘bore hole maser drilling to multiple miles below the earth’.
The jump from lab demonstration to commercial viability is exactly the place where almost every tech trick fails.
So there is no need to pay this thing any attention. Geothermal under ideal conditions is not competitive. Steam turbines have operating costs solar and wind do not.
This is the same reason nukes are a dead end, and D-T fusion besides. It doesn't matter how cheap your heat source is if you need to pay for operating a steam turbine to get any power out. Solar and wind provide high-grade energy directly, so are impossible to compete with anywhere they work.
There are uses for direct heat piped underground to heat buildings, but you don't need to bore to 10km, or even 3km, to get enough heat for that.
So there is no need to pay this thing any attention. Geothermal under ideal conditions is not competitive. Steam turbines have operating costs solar and wind do not.
This is the same reason nukes are a dead end, and D-T fusion besides. It doesn't matter how cheap your heat source is if you need to pay for operating a steam turbine to get any power out. Solar and wind provide high-grade energy directly, so are impossible to compete with anywhere they work.
There are uses for direct heat piped underground to heat buildings, but you don't need to bore to 10km, or even 3km, to get enough heat for that.
To a lay person why do you mean by brittle deformation and plastic sand explosive deformation
When something hard is under pressure, it can bend or deform, or it can break or shatter.
Imagine a hammer striking a sheet of metal and the metal denting. For a brief moment, the pressure and heat of the hammer strike causes the metal to deform. Conversely, if the hammer hit something like a sheet of glass, it would shatter.
Plastic in this sense is not like Tupperware plastic at room temperature, but plastic heated when it is first being molded into shape.
Explosive deformation is again like the hammer hitting a sheet of glass- if the glass were already under pressure, breaking it would relieve the pressure causing shards to fly everywhere.
Rock at the surface is relatively cold and under little pressure- it is hard, but brittle, and simply breaks. As you get deeper, it is under more pressure and as it breaks, that pressure can get relieved unpredictably (fault lines cause formerly stable walls of already drilled hole to collapse).
With even more depth comes more pressure but also more heat, which relaxes the crystalline structure of the rock. It can start deforming rather than breaking. Drill bits become less effective as the rock flows around it rather than getting broken up and pumped away.
Edit: if you haven't watched videos of hydrologic presses destroying things on YouTube, you see something like this in reverse; sometimes things can deform a bit, but eventually explode under pressure. The most surprising to be to watch was a deck of playing cards literally shatter.
Imagine a hammer striking a sheet of metal and the metal denting. For a brief moment, the pressure and heat of the hammer strike causes the metal to deform. Conversely, if the hammer hit something like a sheet of glass, it would shatter.
Plastic in this sense is not like Tupperware plastic at room temperature, but plastic heated when it is first being molded into shape.
Explosive deformation is again like the hammer hitting a sheet of glass- if the glass were already under pressure, breaking it would relieve the pressure causing shards to fly everywhere.
Rock at the surface is relatively cold and under little pressure- it is hard, but brittle, and simply breaks. As you get deeper, it is under more pressure and as it breaks, that pressure can get relieved unpredictably (fault lines cause formerly stable walls of already drilled hole to collapse).
With even more depth comes more pressure but also more heat, which relaxes the crystalline structure of the rock. It can start deforming rather than breaking. Drill bits become less effective as the rock flows around it rather than getting broken up and pumped away.
Edit: if you haven't watched videos of hydrologic presses destroying things on YouTube, you see something like this in reverse; sometimes things can deform a bit, but eventually explode under pressure. The most surprising to be to watch was a deck of playing cards literally shatter.
Dave Letterman did a whole series of crushing things with a hydraulic press. Quite entertaining.
> requires an extreme amount of maintenance through its life cycle
Precisely. Calling a plumber to plug a leak or remove a clog 10 miles underground is astronomically expensive.
Precisely. Calling a plumber to plug a leak or remove a clog 10 miles underground is astronomically expensive.
I was mostly thinking about the corrosive power of water when it is extremely hot and contains dissolved minerals as this water will. I doubt very much that you could actually reuse the water. Protecting the equipment, disposing the heat, obtaining make up water, and doing something with the brine are major problems.
I'm not saying that it can not be done. It probably can, but I feel that the article was a little naive.
I suppose that I should say something about injecting high pressure water into the earth. At this depth you are interacting with tectonic forces. High pressure water can unlock existing forces resulting in earthquakes in a manner similar to the quakes triggered by fracking.
In summary, there is a cost for everything. There are few, if any, silver bullets capable of solving major problems.
I'm not saying that it can not be done. It probably can, but I feel that the article was a little naive.
I suppose that I should say something about injecting high pressure water into the earth. At this depth you are interacting with tectonic forces. High pressure water can unlock existing forces resulting in earthquakes in a manner similar to the quakes triggered by fracking.
In summary, there is a cost for everything. There are few, if any, silver bullets capable of solving major problems.
> There are few, if any, silver bullets capable of solving major problems
I'd argue that there are silver bullets for major problems, but once we find them the problems stop being major.
- Sewers were a silver bullet for sanitation
- Many medicines have been silver bullets for many diseases
- Printing press for information distribution
- Telegraph (and later Internet) for fast information distribution
- Rail for moving stuff
I'd argue that there are silver bullets for major problems, but once we find them the problems stop being major.
- Sewers were a silver bullet for sanitation
- Many medicines have been silver bullets for many diseases
- Printing press for information distribution
- Telegraph (and later Internet) for fast information distribution
- Rail for moving stuff
One could use a closed loop system, ie put an u-shaped stainless steel pipe into the borehole.
> quakes triggered by fracking
Where do you get your misinformation from? This seems to be a widely held false belief.
Where do you get your misinformation from? This seems to be a widely held false belief.
Where do you get your false information?
They’re likely referencing something like this [1]. The “fracking earthquakes” have stemmed lazy disposal of well wastewater. Wells can take millions of gallons of water; ideally we’d be treating reusing that water.
—- [1] https://www.usgs.gov/faqs/how-hydraulic-fracturing-related-e....
—- [1] https://www.usgs.gov/faqs/how-hydraulic-fracturing-related-e....
https://www.americangeosciences.org/critical-issues/faq/why-...
"At any one geothermal field, however, the temperature of the geothermal reservoir or the fluid levels/fluid pressure in the reservoir may decrease over time as fluids are produced and energy is extracted. Produced fluids can be re-injected to maintain pressures, although this may further cool down the reservoir if care is not taken. Over time, it is commonly necessary to drill additional wells in order to maintain energy production as temperatures and/or reservoir fluid pressures decline."
{ Cooling of the area. New area. New hole } Loop.
"At any one geothermal field, however, the temperature of the geothermal reservoir or the fluid levels/fluid pressure in the reservoir may decrease over time as fluids are produced and energy is extracted. Produced fluids can be re-injected to maintain pressures, although this may further cool down the reservoir if care is not taken. Over time, it is commonly necessary to drill additional wells in order to maintain energy production as temperatures and/or reservoir fluid pressures decline."
{ Cooling of the area. New area. New hole } Loop.
Whatever they are, they are not as bad as what we are currently doing to our atmosphere!
Unknown unknowns are what usually get you in the end.
More commonly, unknown knowns:
"It ain't what you don't know that gets you, it's the things you think you know that just ain't so."
Usually credited to Josh Billings.
It is, e.g., what turned the Iraq invasion into a national disaster. What was wasted on invading Iraq, to no purpose, could have paid, instead, for the entire transition to wind and solar, decades sooner.
Numerous billionaires minted off the fiasco would not now be actively undermining democratic institutions.
"It ain't what you don't know that gets you, it's the things you think you know that just ain't so."
Usually credited to Josh Billings.
It is, e.g., what turned the Iraq invasion into a national disaster. What was wasted on invading Iraq, to no purpose, could have paid, instead, for the entire transition to wind and solar, decades sooner.
Numerous billionaires minted off the fiasco would not now be actively undermining democratic institutions.
Maybe a little homework is in order? It's not as though no one's thought of this before, or that no one is putting serious money into it.
I remember when cold fusion was discovered in the 1980s. Everyone was very excited - clean, cheap, unlimited power. The environmentalists were horrified.
(Unfortunately, it turned out to be a fraud.)
(Unfortunately, it turned out to be a fraud.)
It (cold fusion) was complete bollocks as you say.
Actually, if you think back, the hole in the ozone layer was captivating environmentalists and so was acid rain. Remember the photos of Scandinavian forests of fir trees stripped of their leaves? Remember the moratorium and then ban on CFCs (Chloro fluoro err thingies) and how the Arctic was errr fixed?
Our cars used to run on leaded petrol. I can still remember the odd yellow coloured verges of the A303 (UK, SW England). If you were headed west to go on holiday to Devon or Cornwall, you would see quite a few laybys with a stall flogging strawberries. Mmmm mildly lead flavoured!
Yum!
Nowadays we have rather odd weather to deal with and a massively reduced biodiversity.
I also remember nuclear fusion and being told by some chaps at the JET in Oxon that NF is about 25 years away. I also had the joke about NF being 25 years off explained to me in around 1998.
NF is still roughly 25 years away but actually I think it really is, give (or don't bother to take) say 25 years.
Actually, if you think back, the hole in the ozone layer was captivating environmentalists and so was acid rain. Remember the photos of Scandinavian forests of fir trees stripped of their leaves? Remember the moratorium and then ban on CFCs (Chloro fluoro err thingies) and how the Arctic was errr fixed?
Our cars used to run on leaded petrol. I can still remember the odd yellow coloured verges of the A303 (UK, SW England). If you were headed west to go on holiday to Devon or Cornwall, you would see quite a few laybys with a stall flogging strawberries. Mmmm mildly lead flavoured!
Yum!
Nowadays we have rather odd weather to deal with and a massively reduced biodiversity.
I also remember nuclear fusion and being told by some chaps at the JET in Oxon that NF is about 25 years away. I also had the joke about NF being 25 years off explained to me in around 1998.
NF is still roughly 25 years away but actually I think it really is, give (or don't bother to take) say 25 years.
The physicists weren't excited. They pointed out that if Pons and Fleischman had been making enough DD fusion to boil water, they'd have been killed by the neutrons.
The internet of the time consisted of NNTP newsgroups. There was a lot of talk about it by a lot of people, and a lot of opinions and claims of expertise. Filtering out what was true wasn't that easy.
I am not a nuclear physicist and nobody I knew at the time was, either, though personally I thought it was one of those too-good-to-be-true things, and sure enough, it was.
My larger point, however, was that there was a lot of pushback from environmentalists who, when faced with a solution to the energy problem, looked for a way to stop it.
I am not a nuclear physicist and nobody I knew at the time was, either, though personally I thought it was one of those too-good-to-be-true things, and sure enough, it was.
My larger point, however, was that there was a lot of pushback from environmentalists who, when faced with a solution to the energy problem, looked for a way to stop it.
What if the temperature was already a fraction away from boiling and the fusion was just barely enough to bring it to boil?
Why spend the limited internal energy of the Earth's core while the much less limited energy of our star, which is conveniently delivered daily to the surface, where it's easy to harvest?
I can understand geothermal energy in very high latitudes, like they do in Greenland, where Sun energy is scarce, and lava is close to the surface. On most of the earth, geothermal energy is much harder to get than solar.
I can understand geothermal energy in very high latitudes, like they do in Greenland, where Sun energy is scarce, and lava is close to the surface. On most of the earth, geothermal energy is much harder to get than solar.
Geothermal goes 24/7. Also don't underestimate winter even in more moderate climates like northern or even central Europe. Sure you'll get some sun, but it's limited to maybe 9 hours and rainy and overcast.
Geothermal may not be cyclical like solar, but it's output varies and the wells can easily stop producing at any time.
At these depths, the walls collapse regularly. It's like drilling into jello
At these depths, the walls collapse regularly. It's like drilling into jello
> where it's easy to harvest
Are we already capable of harnessing enough to power anything actually serious and industrial, rather than a small household with some consumer electronics and lightbulbs somewhere like California, where heating isn't even an issue?
Are we already capable of harnessing enough to power anything actually serious and industrial, rather than a small household with some consumer electronics and lightbulbs somewhere like California, where heating isn't even an issue?
Solar can't be used as a base load since there's no way to store electricity at the scales required. Same with rain water vs tap water.
I’m curious what’s on your mind when you mention geothermal being limited. How many years is “limited“ and how does that practically affect things?
Easily accessible geothermal sources are relatively rare (unless you are willing to drill 10+ km as the article suggests), and picking energy from under your feet may have consequences for the land above, see e.g. [1].
[1]: https://earth.stanford.edu/news/lessons-pohang-solving-geoth...
[1]: https://earth.stanford.edu/news/lessons-pohang-solving-geoth...
Extracting heat from 10 miles underground, means cooling it. What would the impact of cooling it ?
I guess nothing is truly free, even harnessing solar energy comes with a price.
I do not know the numbers, they might be negligible. But curious to hear about the potential 1st and 2nd impact.
[deleted]
Earth is way too big to have any significant impact even if we harnessed for millions of years, which we will likely not need.
The ideal use case for something like plasma drilling, no?
https://en.m.wikipedia.org/wiki/Plasma_deep_drilling_technol...
https://en.m.wikipedia.org/wiki/Plasma_deep_drilling_technol...
I always wonder why places like Yellowstone aren’t used for power generation. Seems more accessible than most geothermal heat sources. Also Hawaii is another place where geothermal energy could make sense.
https://www.usgs.gov/observatories/yvo/news/why-cant-we-dril...
> Geothermal power exploitation in Yellowstone, however, is illegal by act of Congress—the Geothermal Steam Act of 1970 (amended in 1988). This act requires the Department of Interior to preserve and monitor hydrothermal features, like Old Faithful, in units of the National Park Service, and there is a good reason that the law exists. In many places, including California, Nevada, Chile, New Zealand, and Iceland, geothermal power production has altered the behavior of nearby hydrothermal features. There is still quite a lot we don’t understand about how water moves beneath the surface in the Yellowstone area, and it is likely that even geothermal development outside the Park would impact features within the park.
> Geothermal power exploitation in Yellowstone, however, is illegal by act of Congress—the Geothermal Steam Act of 1970 (amended in 1988). This act requires the Department of Interior to preserve and monitor hydrothermal features, like Old Faithful, in units of the National Park Service, and there is a good reason that the law exists. In many places, including California, Nevada, Chile, New Zealand, and Iceland, geothermal power production has altered the behavior of nearby hydrothermal features. There is still quite a lot we don’t understand about how water moves beneath the surface in the Yellowstone area, and it is likely that even geothermal development outside the Park would impact features within the park.
How far from the interesting hydrothermal systems would it need to be? The caldera is enormous.
Getting fusion to successfully work would power humanity forever.
This guy got a form of it working.
https://www.youtube.com/watch?v=9q_IvxWoY4E
Is it a joke? He claims to be able to solve pain in most diseases with basically the same fusion device:
https://primerfieldfoundation.org/issues-treated
He cites three papers on Cell, Nature. The one on Nature does not seem to be related to this "array of magnets"
https://static1.squarespace.com/static/54d7e4ece4b0a551f3b3a...
https://primerfieldfoundation.org/issues-treated
He cites three papers on Cell, Nature. The one on Nature does not seem to be related to this "array of magnets"
https://static1.squarespace.com/static/54d7e4ece4b0a551f3b3a...
I am very skeptical of the claims made on their website. Basically heals (almost!) everything, for the price of 1200 euros. It has all the properties of a scam product.
fission could power humanity forever and already works
To be pedantic, fusion also already works, just not economically!
Likewise, fission: costs too much to bother.
Fusion already powers the planet. We just need to build out the solar panels and wind turbines to collect as much of it as we care to find uses for.
Fusion already powers the planet. We just need to build out the solar panels and wind turbines to collect as much of it as we care to find uses for.
> “If we can get to ten miles down, we can start to find economic temperatures everywhere.
It’s a shame the article doesn’t seem to mention what those temps are.
It’s a shame the article doesn’t seem to mention what those temps are.
It would rather seem to me that despite the challenges, that it should be easier to dig a hole than to do 'Nuclear Fusion' in which case we ought to consider maybe doing more substantial research?
Imagine if we solved this problem and over the scope of 40 years the whole world just went geo and dumped Oil, Solar, Nuclear?
Imagine if we solved this problem and over the scope of 40 years the whole world just went geo and dumped Oil, Solar, Nuclear?
No, geothermal will never work.
Someone posted a more informed comment on Hacker News about 2 months ago. The idea is that if you drill to 5 km deep, let's say, you find very hot rock. But once you extract the heat from that rock, new heat is very slow to come because rock is a good thermal insulator. So, you'd need to produce secondary holes. Lots of them. In the end the math just doesn't work out by orders of magnitude.
Someone posted a more informed comment on Hacker News about 2 months ago. The idea is that if you drill to 5 km deep, let's say, you find very hot rock. But once you extract the heat from that rock, new heat is very slow to come because rock is a good thermal insulator. So, you'd need to produce secondary holes. Lots of them. In the end the math just doesn't work out by orders of magnitude.
Geothermal works fine, in numerous places worldwide today, as may be seen simply by looking.
It just costs more than wind and solar. Same as nukes. Unlike nukes, geo was once competitive without heavy subsidy, in places.
It just costs more than wind and solar. Same as nukes. Unlike nukes, geo was once competitive without heavy subsidy, in places.
Correct me if I'm wrong, but I think geothermal works where the nature has done the work for us. Where there are underground springs that turn hot and the water comes up steaming.
If you plan to drill the holes yourself, you have a lot of work to do. Drilling is expensive, and a single hole will not get you a lot of heat after the initial honey moon period.
If you plan to drill the holes yourself, you have a lot of work to do. Drilling is expensive, and a single hole will not get you a lot of heat after the initial honey moon period.
California has got reliable power from geo for quite a few decades, as has Iceland. Iceland is not awash in geysers.
Geo costs more than renewables, but that was not at issue. It is anyway cheaper than nukes, in places where it is used.
Geo costs more than renewables, but that was not at issue. It is anyway cheaper than nukes, in places where it is used.
Geothermal is not the same as drilling holes down into the earths crust. Geothermal is tapping into natural release of heat from the earth.
...which involves drilling.
Just turn the Spanish Island of Lanzarote into a huge power station, dig 50m deep there, and be done with it.
[deleted]
"Could" eh? Seems like an enormous risk and expense just for a "could" doesn't it? I'd like to see some verified proof that it WILL yield enough geothermal energy to power Earth before we start. "Could" isn't good enough.
[deleted]
Isn't it dangerous? What if Earth will freeze inside because of this and become like Mars or Moon?
We have plenty of active volcanoes and the earth doesn’t freeze. The earth is very big.
We will just line the hole with electric blankets, it will be fine
I've wondered: can you do cheap nuclear power by simply digging a really deep hole and dropping radioactive fuel down there? No need for moderators or control rods or containment (aside from the steam coming out of the shaft?
There have been natural fission reactors in Gabon something like that: https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...
You'd probably have a job getting the permits to do it deliberately.
You'd probably have a job getting the permits to do it deliberately.
And then we eventually cool the core so much that the Earth's geodynamo shuts down.
Is that even possible? Any geophysicists here? Eventually I suppose that would also disrupt the Earth's magnetic field.
Not a geophysicist but I feel extremely confident based solely on Fermi estimates, that humans do not have the capability to extract that much heat from the Earth even if we tried our best for thousands of years.
Never underestimate humanities ability to consume resources.
They thought the US had enough land that it would take 20 generations to settle (it took 2).
That being said, we should probably still do it. Seems like a slower death route.
They thought the US had enough land that it would take 20 generations to settle (it took 2).
That being said, we should probably still do it. Seems like a slower death route.
It is not possible. It is not even a millionth of the way to possible.
It is, instead, cheap concern trolling. Worry instead about money diverted, from building out wind and solar that actually address looming climate disaster, to chase wills-o-th'-wisp.
It is, instead, cheap concern trolling. Worry instead about money diverted, from building out wind and solar that actually address looming climate disaster, to chase wills-o-th'-wisp.
Wind and solar are not a real solutions and would require massive capacity overbuild.
We need to focus on base load replacement, not intermittent “feel good” sources.
We need to focus on base load replacement, not intermittent “feel good” sources.
Wind and solar will get massive capacity overbuild. Cheaply. When the time is right, storage will, too, and not before.
Huh?
You do realize that the numbers you’re being told about solar/wind being price competitive don’t take into account the overbuild required, storage or even the huge transmission costs.
Also, there is no storage option on the horizon, expensive or otherwise.
Wind/solar is a scam designed to build our generation as inefficiently as possible so regulated utilities can earn a return on their bloated assets. They get you to buy into this scam because “climate change”.
You do realize that the numbers you’re being told about solar/wind being price competitive don’t take into account the overbuild required, storage or even the huge transmission costs.
Also, there is no storage option on the horizon, expensive or otherwise.
Wind/solar is a scam designed to build our generation as inefficiently as possible so regulated utilities can earn a return on their bloated assets. They get you to buy into this scam because “climate change”.
You seem sincerely misled. If you consult more reliable sources, you can cut past the propaganda machine, on this and on other topics.
There has always been plenty of money available to people willing to seek to mislead you in this way. It is absolutely legal to publish falsehoods, even in what looks like legitimate media. People who lie to you about X will happily lie to you about Y.
It is embarrassing to learn you have allowed yourself to be misled, but they are often very, very good at it. The US was fooled into invading Iraq, as in previous wars.
There has always been plenty of money available to people willing to seek to mislead you in this way. It is absolutely legal to publish falsehoods, even in what looks like legitimate media. People who lie to you about X will happily lie to you about Y.
It is embarrassing to learn you have allowed yourself to be misled, but they are often very, very good at it. The US was fooled into invading Iraq, as in previous wars.
I worked for a large regulated utility and have been in the energy industry for the better part of a decade.
I am familiar with the technology and the financial incentives that drive utility decisions.
Efficient energy and distributed customer-owned generation scare the shit out of them. The game utilities play is to build/own as many assets as the regulators allow and earn that sweet regulated return.
They absolutely LOVE the idea of overbuilding generation!
I’m not saying climate change is or isn’t real, I’m simply saying that corporate propaganda is leveraging climate change fear to push us into a product that primarily benefits them, not us.
I am familiar with the technology and the financial incentives that drive utility decisions.
Efficient energy and distributed customer-owned generation scare the shit out of them. The game utilities play is to build/own as many assets as the regulators allow and earn that sweet regulated return.
They absolutely LOVE the idea of overbuilding generation!
I’m not saying climate change is or isn’t real, I’m simply saying that corporate propaganda is leveraging climate change fear to push us into a product that primarily benefits them, not us.
pencilguin(1)
Really, now?? You say the problem is we don't know how to drill that deep? Does it not occur to you that whatever you put down your hole will have the same problem?
And how do you plan to keep your hole open? Rock flows at that depth.
And how do you plan to keep your hole open? Rock flows at that depth.
It does not, in fact. But it is hard to keep your drill bit enough harder than the rock to cut it.
[deleted]
Is it really necessary to go so deep? Why not start in the foothills of some granitic massif and drill up? I'm sure you'll get lots of heat!
It's not that 10 mile holes will be necessary everywhere, it's that "10 miles" is the depth necessary to make these worthwhile anywhere.
You don't need to drill 10 miles to get to geothermal temperatures in Iceland, nor in Yellowstone. But you might in Ohio, or Ireland.
You don't need to drill 10 miles to get to geothermal temperatures in Iceland, nor in Yellowstone. But you might in Ohio, or Ireland.
You also don't need to drill so deep if all you're interested in is lower grade heat. For example, at Cornell in Ithaca, NY they've just drilled a 3 km deep hole to evaluate getting heat (at ~90 C) to make hot water for heating the campus.
What was the result of that evaluation?
The temperature is high enough; beyond that we haven't heard yet.
Any paper on this specific initiative? This sounds like a slam dunk for any population center needing district heat.
Here's a website where they're putting up data from the borehole.
https://deepgeothermalheat.engineering.cornell.edu/research/
Note the wireline logs. You can see the radioactivity (which is where the heat comes from) go way up as they reach the crystalline basement rocks.
The technical issue that's going to determine if this is feasible is how quickly water from an injection well can get to a withdrawal well. This depends on the how fractured the rocks are.
https://deepgeothermalheat.engineering.cornell.edu/research/
Note the wireline logs. You can see the radioactivity (which is where the heat comes from) go way up as they reach the crystalline basement rocks.
The technical issue that's going to determine if this is feasible is how quickly water from an injection well can get to a withdrawal well. This depends on the how fractured the rocks are.
Also: publications and presentations
https://deepgeothermalheat.engineering.cornell.edu/publicati...
https://deepgeothermalheat.engineering.cornell.edu/publicati...
Not the same project, but in Otaniemi they drilled 6km to find the project to not work as planned. Unfortunately this was the best article I could find for now: https://www-lansivayla-fi.translate.goog/paikalliset/4558850...
> In Finland, the temperature rises by 18 degrees per kilometer.
The geothermal gradient at Ithaca is a bit higher than that.
Also, correct me if I'm wrong, but isn't Finland mostly underlain at fairly shallow depth by hard crystalline rocks that are more expensive to drill through? At Ithaca, there's a 3 km thickness of sedimentary rocks before hitting that basement rock.
The geothermal gradient at Ithaca is a bit higher than that.
Also, correct me if I'm wrong, but isn't Finland mostly underlain at fairly shallow depth by hard crystalline rocks that are more expensive to drill through? At Ithaca, there's a 3 km thickness of sedimentary rocks before hitting that basement rock.
Grossly oversimplified, inland is swamps & lakes atop crystalline rocks, while Helsinki is landfill punctuated by granite outcroppings.
The caveat is that you will cool the hole extracting the heat, exhausting usable heat the sooner the more you extract. Whether the sustainable heat energy per unit of invested money is attractive depends on circumstances.
[deleted]
Great and let’s accelerate the timeline of crossing the global temperature threshold increase of 1.5 degree Celsius.
Is the amount of heat released this way any concern from the global warming perspective?
As far as I know (which isnt much) Global warming isn't really about heat released in systems. It's about its inability to leave the earth due to greenhouse effects.
While it is a concern if we produce a lot of extra heat, I think the main issue is being able to expect the heat to leave into space. Which is why most of climate change science focuses on greenhouse gases and not heat produced by machines.
While it is a concern if we produce a lot of extra heat, I think the main issue is being able to expect the heat to leave into space. Which is why most of climate change science focuses on greenhouse gases and not heat produced by machines.
No, not at all. The problem of AGW is not due to the calories we are releasing burning fossil fuels. It is because the waste byproduct of CO2 causing a slightly larger percentage of the sun's heat to be retained until the new, higher equilibrium temperature is reached where the trapped heat matches the heat the earth radiates.
This also happens with direct heat release from fuels or geothermal, but at an order of magnitude or so higher energy output.
Speaking of CO2. Capturing CO2 seems to be much less technically difficult than drilling 10 miles down. Various technologies already exist, and pilot plants are running. Perhaps focusing on the practical would be more productive than an illusory silver bullet.
It's not just CO2. It's CO2 and all the other greenhouse gasses.
And regardless, capturing them takes a lot of energy and unless we have a clean source (such as geothermal for example), that means that we will be releasing more greenhouse gasses than the produced amount of energy will capture.
And regardless, capturing them takes a lot of energy and unless we have a clean source (such as geothermal for example), that means that we will be releasing more greenhouse gasses than the produced amount of energy will capture.
It is far more efficient to not emit CO2 than to recapture it. It's worth doing the napkin math on how much air needs to be processed to undo one American's yearly CO2 footprint... It's a hell of a lot.
The thermal forcing from emissions are on the order of 20x the direct thermal forcing.
Any energy releasing process (nuclear, fossil fuel with ccs, geothermal) is bounded somewhere around 10-20x current energy use by running into direct thermal forcing.
PV produces less waste heat depending on where it is installed so has a slightly higher limit, but both solar and wind have pretty severe land use limits you run into at 20-100x current global energy.
Basically, everyone can have enough energy to flourish, but it's time to reign in growth and maybe dial it back a bit from US levels of consumption.
Any energy releasing process (nuclear, fossil fuel with ccs, geothermal) is bounded somewhere around 10-20x current energy use by running into direct thermal forcing.
PV produces less waste heat depending on where it is installed so has a slightly higher limit, but both solar and wind have pretty severe land use limits you run into at 20-100x current global energy.
Basically, everyone can have enough energy to flourish, but it's time to reign in growth and maybe dial it back a bit from US levels of consumption.
If so I would think any power generation that uses steam would have the same issue? Coal, gas or nuclear.
(Even if it were feasible) Just another expensive way to boil water?
“Digging 10 miles underground” is like “building a solar panel the size of California” — really useful if you can find a feasible way to do it
Feasibility is kind of what the article is about. Also, this quote seems salient:
>> Finally, Houde said, geothermal is “the perfect energy source to take advantage of the largest workforce in the world, the oil and gas industry.” That industry has “11 million jobs in the US alone, and a skill set that is exactly what’s needed for geothermal to rapidly scale.”
>> Finally, Houde said, geothermal is “the perfect energy source to take advantage of the largest workforce in the world, the oil and gas industry.” That industry has “11 million jobs in the US alone, and a skill set that is exactly what’s needed for geothermal to rapidly scale.”
There's a thing when you get to only about a mile or two down and happen to strike vastly rich oil reserves. Then you're a billionaire already so what's the incentive to continue going all the way?
If ICE vehicles fall out of fashion, oil will still be immensely useful for chemical refinement but with nowhere near the demand that burning it has. It'd still be a fortune but a slow one rather than a "drain it as fast as possible to print money" kind.
Digging deep holes for geothermal guarantees the industry a future at this scale when the move to electric inevitably happens. The alternative is for them to pass up the opportunity and solar, wind, and nuclear to eat their lunch.
Digging deep holes for geothermal guarantees the industry a future at this scale when the move to electric inevitably happens. The alternative is for them to pass up the opportunity and solar, wind, and nuclear to eat their lunch.
What is the probability of oil getting in the way of an arbitrary hole whose position is picked for other reasons. Such as proximity to large population.
> “Digging 10 miles underground” is like “building a solar panel the size of California” — really useful if you can find a feasible way to do it
Kola already reached 76% of the way there.
https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
Kola already reached 76% of the way there.
https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
If we had a solar panel the size of California, what would we do with it? Is there a flat contiguous area of land that size where no one lives, or does it float in the ocean?
I guess the idea is that since we're imagining things that don't exist anyway, we could assume the panel is made of invisible pixie dust. But at least for me, drilling a ten mile hole is intuitively easier to envision.
Maybe that's ill-informed on my part, I don't know, but it's why the idea is appealing. It instinctively seems like a feasible task.
I guess the idea is that since we're imagining things that don't exist anyway, we could assume the panel is made of invisible pixie dust. But at least for me, drilling a ten mile hole is intuitively easier to envision.
Maybe that's ill-informed on my part, I don't know, but it's why the idea is appealing. It instinctively seems like a feasible task.
The Sahara desert and Australia are huge but at least for the thermosolar farm in the Moroccan desert, the difficulty is transporting the electricity far enough to sell it.
https://en.wikipedia.org/wiki/Ouarzazate_Solar_Power_Station
https://en.wikipedia.org/wiki/Ouarzazate_Solar_Power_Station
Another option is to build it in space.
Lots of room there.
Lots of room there.
It's easy to generate solar power in space, but difficult to do anything with it.
Let's see, area of california = 423k km2. Check.
Largest solar park in the world = 57 km2, cost 1.3B$. Check.
Total cost of a solar panel the size of california, with the help of the most intricate indian technology = 9.6T$
Largest solar park in the world = 57 km2, cost 1.3B$. Check.
Total cost of a solar panel the size of california, with the help of the most intricate indian technology = 9.6T$
This thing bobs to the top of HN every few weeks.
1. No, there is absolutely no hint of any danger of extracting too much heat, no matter what random problem you make up. Really.
2. A 10km deep hole gets you 1/600th of the way to the center of the planet, much less than e.g. the skin of an apple or the enamel on a billiard ball. So, it would tell you nothing about stuff deeper, never mind bollocks it.
3. Geothermal energy is not a major growth sector even where heat is right near the surface. Geothermal, like nukes, costs too much to ever be competitive again.
Wind & solar cost less already, and get much cheaper every year. There is no need for, or value in, more expensive alternatives. It is a good thing that solar and wind are simple and uninteresting.
Places where both wind and solar do not suffice can continue importing fuel, as they do today, indefinitely. Eventually, it will be synthetic, or delivered by transmission lines. Tropical solar farms will synthesize ammonia for export.
1. No, there is absolutely no hint of any danger of extracting too much heat, no matter what random problem you make up. Really.
2. A 10km deep hole gets you 1/600th of the way to the center of the planet, much less than e.g. the skin of an apple or the enamel on a billiard ball. So, it would tell you nothing about stuff deeper, never mind bollocks it.
3. Geothermal energy is not a major growth sector even where heat is right near the surface. Geothermal, like nukes, costs too much to ever be competitive again.
Wind & solar cost less already, and get much cheaper every year. There is no need for, or value in, more expensive alternatives. It is a good thing that solar and wind are simple and uninteresting.
Places where both wind and solar do not suffice can continue importing fuel, as they do today, indefinitely. Eventually, it will be synthetic, or delivered by transmission lines. Tropical solar farms will synthesize ammonia for export.
Let's just suck out the energy that powers the internal convection that powers the magnetic field that prevents the solar wind from stripping the atmosphere of water, what could go wrong? On a small scale, no problem, but "powering the Earth" with the dynamo that prevents us from becoming Mars/Venus? It'll be great until we suck too much energy out. CO2 will seem like a cakewalk by comparison. At least we know the planet is livable with high levels of CO2, and we know that the rocks and trees soak up CO2 and that the ocean precipitates it out as limestone, so if worst comes to worst we can just wait a while. Once the dynamo stops, it's not restarting, and we've got maybe 50 million years until things are unlivable. Forever.
Now maybe we don't think we'll actually make it as a species for that long. But we should think about the risk, this time around.
Now maybe we don't think we'll actually make it as a species for that long. But we should think about the risk, this time around.
I think you overestimate how much energy humans use. We are just very inefficient.
Also, said "dynamo" has been running for a few billion years. We've no concept of how long that is. No mental model. Im sure the the planet will be just fine.
Also, said "dynamo" has been running for a few billion years. We've no concept of how long that is. No mental model. Im sure the the planet will be just fine.
What exactly do you mean by "fine", that you're so sure of?
I hear the phrase a lot, "the planet will be fine". Sure it'll continue to be a ball of matter that orbits the sun a few billion more times, so in that regard it'll do pretty fine as a planet. That's not what people are concerned about when they say they're worried about Earth though.
I hear the phrase a lot, "the planet will be fine". Sure it'll continue to be a ball of matter that orbits the sun a few billion more times, so in that regard it'll do pretty fine as a planet. That's not what people are concerned about when they say they're worried about Earth though.
https://earthscience.stackexchange.com/questions/428/could-t...
[1] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget
[2] https://yearbook.enerdata.net/electricity/electricity-domest...
Internal heat generation is estimated by Davies and Davies (2010) to be roughly 47 Terawatt. With a surface area of 5.1 × 10 m^2, this translates to roughly 0.1 W/m^2.
CL4P-TP comment:
"The earth produces 20TW[1] of thermal energy from radioactive decay in the mantle. This is the amount of warmth that the earth generates, so it should give us a ballpark idea of how much heat we would need to remove from the earth in order to make an impact on the earth's internal temperature. To summarize the heating situation under earth's crust, the existing heat comes from two sources in ~equal parts: radioactive decay, and leftover heat from the earth's creation[1]. Lots of heat hits the earth from the sun but gets radiated back out; It doesn't really have anything to do with internal temperatures[1]."
"As far as I can tell from that wikki page: Current heat in the earth: ~50% radiation, ~50% leftover Internal heat budget: Geothermal Power Consumption + 47TW transferred from the mantle to the crust and beyond[1] - 20TW generated from radiation = Core cooling rate Core cooling rate without geothermal: 0 + 47TW - 20TW = 27TW
The world consumed 22,000 TWh in 2017[2]. That means an average power consumption of 2.5TW.
If all of that was geothermal, we'd be increasing the cooling rate of the earth's core by about 10%."
[1] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget
[2] https://yearbook.enerdata.net/electricity/electricity-domest...
Internal heat generation is estimated by Davies and Davies (2010) to be roughly 47 Terawatt. With a surface area of 5.1 × 10 m^2, this translates to roughly 0.1 W/m^2.
CL4P-TP comment:
"The earth produces 20TW[1] of thermal energy from radioactive decay in the mantle. This is the amount of warmth that the earth generates, so it should give us a ballpark idea of how much heat we would need to remove from the earth in order to make an impact on the earth's internal temperature. To summarize the heating situation under earth's crust, the existing heat comes from two sources in ~equal parts: radioactive decay, and leftover heat from the earth's creation[1]. Lots of heat hits the earth from the sun but gets radiated back out; It doesn't really have anything to do with internal temperatures[1]."
"As far as I can tell from that wikki page: Current heat in the earth: ~50% radiation, ~50% leftover Internal heat budget: Geothermal Power Consumption + 47TW transferred from the mantle to the crust and beyond[1] - 20TW generated from radiation = Core cooling rate Core cooling rate without geothermal: 0 + 47TW - 20TW = 27TW
The world consumed 22,000 TWh in 2017[2]. That means an average power consumption of 2.5TW.
If all of that was geothermal, we'd be increasing the cooling rate of the earth's core by about 10%."
If we take out too much energy, will the gravity run out? That would be concerning
I believe that Futurama has answers.
If we take too much heat, we can just plant all of our nukes deep down and rekickstart the process.
I, and the director of the movie "The Core", agree completely.
See Netflix show 'Into The Night'