Why don't we drill to whatever is the termal limit, make a big cavity there, install radiators there and just heat the watter to that temperature and take it out to surface where we can heat homes.
I know this is done in Bucharest for a water park (to much lesser depths because apparently we have hot springs near Bucharest).
Do we need to reach magma?
And the temperature to destroy steel under the immense mechanical stress of a drill string is surprisingly modest. Jet fuel can’t melt steel beams, but softening them is enough.
This is why wooden sauna seats work well, aluminum seats in the sauna would not go over so well.
Lots to consider when solving thermal problems, it's not just about turning up the dial to be able to withstand more heat. Sometimes it's about the nuance of moving the heat efficiently and putting it where it's wanted, and not where it isnt.
My general rule is that everything is 1 J/g/K except water, which is 4.2. It's obviously not true, but almost always within a factor of 2, and 1 is an especially easy number to multiply and divide by.
Reading your second paragraph, I see you're familiar with the principle, and added a good heuristic to my stockpile, thank you.
ISWYDT.
You need a thermal gradient to move heat from the surrounding rock to the water your pumping in. The higher the initial temperature the larger the difference and therefore faster you can extract heat. Aka even if the working fluid is at a constant temperature you can simply pump it faster.
Also, Carnot efficiency limits means you want the hottest steam you can handle. Further, you have various inefficiencies such as losing heat as water moves back up a borehole.
Nope. Over the last ~20 years the drilling industry has gotten good at: angle drilling (not slant drilling but turning the drill angle at the bottom) and fracking, or pumping fluid through rock to break it up. This means conventional methods can dig far down, turn the drill and make a reserve with fracking. The heat is much less but it's conventional technology.
https://www.ted.com/talks/jamie_c_beard_the_untapped_energy_...
Nooo --- don't dig the Well to Hell!
To flip that around: this would imply that the most under-investigated-in-industry approaches to deep hole boring would be the ones that destroy the economic value of any oil-and-gas in the ground, no? Ones that make the ground radioactive, perhaps. Or that would set any potential oil fields on fire, or react them away, or irrevocably mix a combustion-inhibiting azeotropic solvent into them.
https://en.wikipedia.org/wiki/Project_Gasbuggy
Regarding drilling operations that destroy value: you're forgetting that drilling is 1D while oil fields are 3D (technically quasi-2D with horizontal dimensions 100x to 1000x larger than vertical dimensions). If your drilling messes up everything in a 10 meter radius from the drill string, you don't care.
Likewise, everything that conceivably could be done with nuclear was tried or at least designed for a while there - lighting watches with radium, digging canals with nukes, space travel by continuously exploding nukes behind you... good times. (Horrifying times, but w/e;])
"The top secret plan to explode a nuclear bomb in Yorkshire", by Tom Scott: https://www.youtube.com/watch?v=ceWZslOfEjs
It would buy controlling interests in all the companies that make some critical, specialized and heavily patented piece of modern internal combustion engines or coal turbines. Then, it'd wreck the factories, and patent troll everyone else into not producing.
Money is speech, and that would be protected political speech, right? :-)
That's just not true. Misery and suffering is it's own reward, to some. This is arguably the main point of Orwell's 1984, when O'Brien explains to Winston Smith why they bother torturing people before killing them. O'Brien says that to knowingly cause suffering in someone is the ultimate expression of power, and it is axiomatic to him that power is good in-and-of-itself.
I've never actually thought about whether patent protection covered just the sale, or the manufacture, or exactly what, so thanks for bringing that nuance to my attention!
That is only one explanation to why a technology would be among the most under-investigated-in-industry approaches. There are many others, such as:
- It does not work at all.
- It is more expensive than traditional methods
- It is illegal in some way
- It is incompatible with the rest of oil&gas processing.
Whereas for geothermal, conventional drilling isn't useful enough for it.
Geothermal heating provides unlimited fuel for people in houses, staying still.
The technology is similar, and it's boring ;-) The market is different. This is an opportunity for entrepreneurs to hire expert drilling engineers out of the oil industry!
This sounds like the beginning of a great sci-fi novel.
A future where Earth's core has cooled because of excess draws to power humanity. Now, the planet is losing it's magnetic field.
To save humanity, humans need to re-heat the core, build biospheres, or leave the planet.
Has anyone done the napkin math for how long that would take?
https://www.forbes.com/sites/alexknapp/2013/04/28/the-center...
Core of earth: 6,000 ºC
https://www.space.com/why-sun-atmosphere-hotter-than-surface
Core of sun: 27 million ºC Surface of sun: 6,000 ºC
"The leading idea among experts is the sun's magnetic field is actually bringing energy from inside the sun up through its surface and into its atmosphere."
The "napkin math" will involve gathering some data about RF power harvesting, and some assumptions (e.g. cosmic rays)
https://news.mit.edu/2020/energy-harvesting-wi-fi-power-0327
https://en.wikipedia.org/wiki/First_law_of_thermodynamics
Do you believe in the 1st law of thermodynamics, that energy is neither created nor destroyed?
https://en.wikipedia.org/wiki/One-electron_universe
We could just balance the system:
core of Earth too hot -> use geothermal
core of Earth too cold -> use solar power
https://news.ycombinator.com/item?id=30476002
It's even more interesting that you mention the magnetic field, could we use solar panels to draw more energy from the sun to power a tesla coil and microwave the core?
(it was not great)
As a kid, my cousin, my sister, and myself were able to dig a hole deep enough for me to be completely inside in an hour or two using a post hole digger. (Yes, this is a very stupid idea.)
More importantly, geothermal/ground source is rarely 1 well either, in our case it was 8.
It’s just a huge vertical drill with segments you add on as it goes deeper, like an oil well drill.
(although on rereading I didn’t mean to say ‘huge’ twice in my previous post)
I'm actually considering if it makes sense to push a lot more heat into it in the summer (Deliberately leaving curtains open, then moving this heat into the well; or even PVT panels), but I'm not sure if the well would retain heat long enough to make a difference towards the winter.
Your system should give a an overview of your yearly input/output and any drift of the well temperature right?
GA Drilling was pushing plasma drilling back in 2018.[2] They're still pushing it, but not making holes.
The University of Minnesota was pushing electro-pulse boring in 2015.[3] Again, no deep holes.
There's something called ThermoDrilling, which, despite the name, is more like a water jet cutter.[4]
Successful projects are still using mechanical drilling.[5]
So there are a lot of deep hole drilling approaches being studied. Anything that works would be used by the oil and gas industry, and if they're not trying it, one suspects it might not be working.
[1] https://www.researchgate.net/publication/270653673_Microwave...
[2] https://www.gadrilling.com/
[3] https://experts.umn.edu/en/publications/electro-pulse-boring...
[4] https://www.geodrillinginternational.com/deep-geothermal/new...
[5] https://geothermalengineering.co.uk/united-downs/