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.
"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"
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.
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.
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.
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.
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.
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.
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]
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.
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.
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”.
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.
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.
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).
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.
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.
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.
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.
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.
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)
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:
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.
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" :)
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.
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.
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?
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.
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.
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.
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.
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.
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.
"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."
"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.
I remember when cold fusion was discovered in the 1980s. Everyone was very excited - clean, cheap, unlimited power. The environmentalists were horrified.
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.
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.
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.
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.
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?
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].
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.
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.
> 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.
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.
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?
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.
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.
"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.
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?
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.
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.
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.
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.
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.
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.
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.
> 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 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.
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.
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.
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.
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.
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.”
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.
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.
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.
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.
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.
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.
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.
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%."
