For those who prefer a less American-centric metric: 8,000–9,000 feet is approximately 2.5 kilometers. 15,000 feet is about 4.5 kilometers — roughly the height of 14 Eiffel Towers stacked on top of each other!
https://en.renovablesverdes.com/iceland-is-drilling-the-deep...
https://global.chinadaily.com.cn/a/202411/07/WS672c6803a310f...
The usual value for the geothermal gradient is 25 to 30 degrees C per kilometer. So at 2.5km, in most locations they might be able to get boiling water, but not superheated steam. Most of the geothermal enthusiasts are talking about needing to go down 4 to 12 kilometers. Is there something special about the geology at this site?
I wonder, if we draw enough heat out... would the core cool enough to shrink? And if so, would the crust collapse to the new size?
Pure speculation of course, but did the first guy burning coal know the outcome?
Anyhow, I love geothermal, think you're right, but just got tweaked on the word "infinite".
And more: https://www.complexsystemspodcast.com/episodes/fracking-aust...
One interesting point made here is that the cost of turbines puts a floor price on any form.of generation which uses them, whether renewable or not, meaning in the long run solar has a big advantage: https://www.dwarkesh.com/p/casey-handmer. I don't know how accurate that is
Beaver County, Utah, has at least one hot spring, and I suspect more than that. I'm pretty sure that the location for this project was not chosen at random.
https://www.size-explorer.com/en/compare/buildings/eiffel+to...
Q = m c ΔT
m = mass of the crust (roughly 10^22 kg)
C = specific heat of crust (roughly 1000 J/kg·K)
ΔT = 1 K
Q = 10^25 joules would be needed to lower the earths crust by 1 degree K
About 10,000 years worth of today’s human energy consumption
The US has long been the world's leading producer of geothermal power, mostly generated from this basin.
I don't know if it's "no footprint" at all. For what I know, which is not much, but just what a person living here might know, there's a footprint that can be somehow managed. But I'm not an engineer
Whaste heat from nuclear or fusion does contribute to earth heating, though insignificant compared to any source pf c02.
But my intuition tells me geothermal wouldn't...
Mm. Actually, water vapor is a potent greenhouse gas; and that's how to covert heat to energy. So mabie it would indeed be significant.
‘home geothermal’ isn’t really a thing unless you’re already living on a hotspring, which is quite unusual. (delta-v is not sufficient)
At the point someone is drilling km+ boreholes and installing MW+ turbines, it’s safe to call it commercial.
Home geothermal /could/ be a power source, sure, but I do not believe that’s what OP intended to say when mentioning heat pumps. I’d be pretty surprised if it was becoming common in Europe to have home geothermal
A heat pump (which are more common in Europe, but they’re gaining popularity in the US) is essentially a reversible air conditioner that can take advantage of the latent energy in the air to move heat very efficiently. They’re a great invention, but they have nothing to do with producing energy
They deserve big props for this innovation and effort, as historically Utah has frequently been been treated as an industrial dumping grounds. The long-term ecological damage and visual eyesores due to strip mining, chemical dumping and other pollution is significant.
1 Statue of Liberty (including foundation) is roughly 1 American football field (excluding end zones)
1 Eiffel Tower is around 3 Statues of Liberty (each with foundation)... which is almost 1600 bananas
It is mostly an issue in places like Europe that do not have a history of strong earthquakes and therefore lack seismic resistance civil engineering. There are a few places like that in the US (e.g. New England) where a minor M5 earthquake can cause damage but those don't overlap with areas with high geothermal potential.
Also... Iceland. They're massive in aluminium production for a reason. They have basically infinate abundant energy boiling out from the ground. Here in sweden its used by alot of homes for heating; getting a well producing 60c water is pretty cheap. (A single home may have their own well)
The issue is using it for power really only becomes viable when you reach superheated steam temperatures. And at those depths; drills melt, so its use outside of volcanic regions has been real slow.
https://www.energy.gov/sites/prod/files/2014/02/f7/geotherma...
Geothermal turns turbines with steam that then produces massive quantities of electricity. That makes it an energy source. The water way down under the ground in these cases is superheated by the surrounding rock, and provides plenty of high quality heat. There are no heat pumps involved.
It’s like the difference between having a pool in your backyard, and damming a huge river and installing turbines.
If I recall they touched on how US oil drilling companies with lots of experience in horizontal drilling were being used by these companies & the financing that goes into them.
We know how weather works quite well, but knowing if it will rain in a week is an entirely different beast.
(1GW of solar PV is deployed every 15 hours globally as of this comment)
It's not a fully renewable resource. It's possible to pull out too much heat too and deplete the resource. The entire geothermal heating of the planet is only 50 terawatts, which seems big, but it's spread over 500 million square kilometers. Or 100KW/km^2, which is not much. Solar is orders of magnitude larger.
Heres a presentation we did on the system last year alongside Schlumberger. https://m.youtube.com/watch?v=kfOGKfEoPb0?t=7852s Potatoe quality but my part starts at 2:10:52.
It’s absolutely awesome deploying our super rugged, super high temp drilling technologies for GeoThermal.
If you’re interested in working on this kind of tech we’re hiring.
And 50 football fields would mean a lot more, to less measurement-aware Americans.
My memory is that the calculation found that if humanity switched to geothermal for all its energy needs, then in only about 1000 years, the core cools enough for the magnetic field to stop, but I am not sure.
(We should definitely deploy geothermal in the Yellowstone caldera though long enough to cool it down enough so that it will not erupt again.)
Most people have enough trouble believing that their foot is the same length as their forearm. You never see your feet close up, either.
Easy peasy.
Now, that energy is coming from somewhere else (in this case, the heat of the ground beneath the house or the air outside), but that's true of electrical generators as well.
Global warming isn't happening due to industrial waste heat - it's happening due to CO2 emissions being a massive leverage for messing with how the planet absorbs and emits heat.
All jobs onsite in Houston: https://www.erdosmiller.com/jobs
Interesting that the tech sales job is bilingual (haven't seen that too often).
Even at million+ year timescales, I can’t see any way the temperature of the upper crust could matter to the core at all - even if the crust was at absolute zero.
Dirt insulates relatively well, and the amount of thermal mass present is mindboggling.
He said ‘BEAUTIFUL, CLEAN COAL’
https://truthsocial.com/@realDonaldTrump/posts/1141801993510...
We have a whole fleet of geothermal plants (15ish), making about 20% of our power. However the largest plant is only 160MW.
The impact in comparison to our other renewables seems fairly minimal.
https://en.wikipedia.org/wiki/Geothermal_power_in_New_Zealan...
Pro-geothermal position: https://www.caltech.edu/about/news/producing-clean-energy-ca...
Anti-geothermal position: https://news.stanford.edu/stories/2019/05/lessons-south-kore...
My conclusion: Geothermal makes research into plate tectonics and earthquake mitigation considerably more valuable, so we can figure out how to do it in a way that reduces earthquakes rather than creating them.
Fun fact: Plate tectonics has been proposed as an explanation for why complex life is here and not elsewhere.
More than 900 shallow wells have been drilled at Rotorua for space and water heating for private homes, hospitals, schools, motels, hotels, and other commercial and industrial uses. At peak use, around 430 wells were operating. Currently fewer than 300 production and injection wells are operating, for approximately 140 consents takes. About 90 of the wells are less than 200m deep and typically recover geothermal fluid at temperatures of 120 to 200°C.
Heat pumps go way beyond a COP of 1; an open-loop cooling system with an evaporative cooling tower can have a COP of 7. A closed loop heat pump alone can have a COP of 4.
Peltier devices are a dead end for moving heat around outside of specialized applications where you can’t drag around two heat exchangers, a valve, and a pump (like active cooling clothing). It’s impossible for them to even approach the efficiency of resistive heating (COP of 1).
Geothermal systems don’t strictly need to produce energy with steam, I just completed a project to convert some boilers and chillers with heat recovery chillers and a geothermal loop for heating and cooling at a research lab for an S&P 500 constituent. I’m doing another project to replace some existing geothermal heat pumps for another customer this fall, no power generation, just heating and cooling.
The different between these two ideas, is that a heat pump is not producing heat (as it's primary goal). It's concentrating and moving heat from point A to point B. The amount of heat moved may exceed the amount of raw energy used to perform this process (and should, in most situations), HOWEVER, it can not exceed the amount of energy you would get back by trying to reverse the process to extract energy. It is still a net energy consuming process.
This is important, because if it wasn't - you could power the heat pumps off their own output, and you'd literally have infinite energy/perpetual motion machine. Which would be awesome. It is also impossible, near as we can tell.
What actually happens is everything grinds to a halt, because the useful (Actual) energy output from the heat pump is lower than the energy required to run it.
Chances are, that system isn't even really geothermal (as in using latent heat of the planet) - any large enough mass would do the same thing. People just like to say the word because it sounds 'green'. If the ground was hot enough (for instance) to provide actual heat itself, a heatpump would be a waste for heating the building - and extremely inefficient for cooling it. It would be better to just pipe water straight out of the ground to heat, and use air based HVAC to cool.
Geothermal power generation does produce power - by tapping into a source of heat so hot that the difference between normal atmospheric temperatures and that heat source allows us to generate useful power. A heat pump gets in the way and causes losses in these situations.
Unless you're sitting (quite literally) on a hotspring, this requires going VERY deep into the ground. Which is what this article is about.
I get the vibe that your definition of "producing power" is electrical power generation. However the original argument is that there is energy being extracted that is not in the form of electricity.
Kind of joking: unless there are nonlinear effects near 300K? Fig 4 [1] seems to suggest that the thermal diffusivity of the mantle grows very fast as temperature declines past 300K... but the data stop at 200K.
Reason for initial comment: we could probably set up a spherical heat equation to guess how crust cooling would change heat conduction at the outer core. But I have absolutely no idea how to reason about changes in heat conduction affecting the convection dynamics that generate the field. I was silently hoping for one of the domain experts lurking this forum to see it and share wisdom. (But overall it was a silly question, I know).
[1] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/200...
You used the energy from the wall socket to pump the heat from outside into the inside, less efficiently than you could use that heat to generate more electricity or do other work later.
Aka you pumped the energy inside and concentrated it a bit. You didn't generate more energy than you had before. You did make existing energy more useful for you, comfort wise.
Actually operating one, you'll see that the energy cost of a heat pump becomes proportionally higher as the temperature difference gets bigger, so you spend more energy moving the heat when the source is low temperature and the output is high temperature.
Many people have gotten quite frustrated when they end up chilling the ground in their ground source heat pump too much, and they end up with very inefficient systems.
You could do the exact same thing (with better or similar efficiency) by using some other source of thermal mass. Air sourced heat pumps do it with the atmosphere. It's possible to use lakes and other bodies of water.
No net usable power is being extracted from the earth in this scenario. The earth is being cooled in order to heat your house. And heated, in order to cool your house.
Geothermal power systems do produce actual usable power, and they do so by running a heat engine (the opposite of a heat pump) off an extremely large temperature difference from a very large source of underground heat. You can't run a heat engine on the output of a heat pump and produce net power, anymore than you can hook a generator to an electric motor and produce net power.
>That is not what ‘power source’ means. You probably want to read up on some thermodynamics and definitions. I’m guessing you think that if you connect the heat pumps output to it’s input, you’ll have infinite energy?
There is no answer in that whole comment to my question. However, you did answer it in the comment I am replying to:
> you pumped the energy inside and concentrated it a bit.
Yes! That's exactly right. But furthermore:
> You didn't generate more energy than you had before. You did make existing energy more useful for you, comfort wise.
This is exactly right, and it is also known as the first law of thermodynamics. [1]. There is no way to produce energy. Even with electrical generation from geothermal, we are moving energy and concentrating it a bit, as you say, just in different forms.
[1] https://en.wikipedia.org/wiki/First_law_of_thermodynamics