Mathematics of Geothermal Energy

Disclaimer: I work in this field.

This is a very brief, high-level overview. It weirdly dives deep into some less-relevant topics and glosses over a LOT of things.

It is not irrelevant, but not terribly reliable either. The "Mathematics" in the title is self-evidently clickbait.

YMMV.

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Heliosmaster 5 hours ago | parent [-]

Would you be open to do one yourself and share it? (Not sarcastic, just asking)

	▲	fghorow 4 hours ago \| parent [-]
		Honestly, to do anything like justice to this topic would require a publishable academic paper. That is something I simply do not have time for. There are (at the very least) 2 reasonable places I can think of off the top of my head in which to look around for answers -- both are organizations that run annual meetings on the topic of geothermal energy. One is the Geothermal Rising professional organization [1]. There is a claim on the website that the papers from the annual meeting (roughly a month back) are available for free download by anybody. I can't find the actual head-link for those papers. A search engine is your friend. (I would not trust an LLM for this particular job.) A second one is the Stanford Geothermal Workshop [2]. That is also an annual meeting. Again, use a search engine. Sorry to not be more helpful, but this is a pretty large topic. [1] https://www.geothermal.org/2026-geothermal-rising-conference... [2] https://geothermal.stanford.edu/events/workshop/past-proceed...

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__MatrixMan__ 4 hours ago | parent | prev | next [-]

The general shape of geothermal, where you're up here where it's cool, and you push a fluid down there where it's hot, and you bring the heat back up here to do work... Would a good enough insulator make it thermodynamically feasible to do it from an airship in the Venusian atmosphere?

Like, clearly Earth's crust supports temperature gradients which are steep enough to make the juice worth the squeeze. Presumably you're not going to find gradients so steep in the case of a runaway greenhouse effect, but whatever gradients you do find, are there fundamental limits preventing them from being steep enough?

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alexpotato 3 hours ago | parent [-]

The "airships riding on clouds of Venus" is a scifi genre that we need way more of.

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kurthr 2 hours ago | parent [-]

To be at 1 atm you need to be way up near 50km, but you'd probably want to be up closer to 55km to get temperatures down, filling it with higher concentration O2 to make it breathable. Making the envelope durable would be pretty crazy in H2SO4, but maybe Ti would self passivate?

Arguably, more dangerous and harder to navigate than vacuum.

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bilbo0s 31 minutes ago | parent [-]

You guys are imaginative, I'll give you that.

But there are so many more fundamental problems with the high altitude Venusian colony idea that you would never get to the "temperature gradients > power" pipeline implementation in any case.

I mean right off the bat, imagine building or navigating anything in hurricane Katrina. Then, since we're talking 50km, imagine winds that would make the forces you're dealing with an order of magnitude more problematic.

Yeah, in terms of knowledge and technology, mankind is just not there yet to be perfectly frank.

	▲	IAmBroom 2 minutes ago \| parent [-]
		Wind speed could be fairly irrelevant to the balloon-city; it will never touch "ground". If you can steer away from vortexes (assuming them to be rare), they simply don't matter as a safety issue. (Staying in a desirable temperature zone could create a need for resisting the wind, but that's not a safety issue.) OTOH, because wind velocity is highly tied to altitude on Venus, wind farming could be an important source of energy generation (along with chemical generation for emergency demand). Drag a fan at a hotter, lower, higher-pressure altitude, and harvest the electricity. In fact, storing an excess of wind-farm energy as chemical energy could power the occasional need to steer away from vortexes. If the problem of a chemically-inert package can be solved, floating inhabited stations could be feasible.

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sghiassy 6 hours ago | parent | prev | next [-]

Wish geothermal energy was being discussed more for a power source for data centers.

Iceland has unlimited geothermal energy and a cold climate. Seems a lot easier than going to space for solar energy

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alexpotato 3 hours ago | parent | next [-]

In Michael Lewis book Boomerang [0], there is a chapter about Iceland and he mentions geothermal.

My understanding:

- b/c of geothermal, huge amounts of electricity are available for low cost

- Iceland being an island makes it VERY expensive to build/transport goods back and forth

- The above combo means that aluminum smelting is the only industry where the electricity availability outweighed the costs of transport and being on an island.

0 - https://amzn.to/4j8r3bO

	▲	sghiassy 34 minutes ago \| parent \| next [-]
		I have heard about the benefits of aluminum smelting there before. We already have transatlantic fiber optic cables so I don’t see why “transportation” costs apply here though
	▲	riffraff 2 hours ago \| parent \| prev [-]
		Crypto mining was often mentioned too, but I seldom hear of icelandic Bitcoin miners these days.

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idontwantthis 5 hours ago | parent | prev | next [-]

It’s hard to come up with any idea that is not easier than going to space for solar energy.

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gus_massa 4 hours ago | parent | next [-]

It's easier to dump all the excess heat in Iceland than in space.

	▲	maybewhenthesun 3 hours ago \| parent [-]
		I read it as 'it's easier to dump the execs in Iceland than in space` :-D Which might be true, though the second thing sounds promising as well...

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account42 5 hours ago | parent | prev [-]

Lots of hamsters in wheels driving tiny generators?

	▲	idontwantthis 5 hours ago \| parent [-]
		I’m not going to bother to check the math but Gemini estimated $20billion/y to generate 1gw with hamsters on wheels so honestly that could be competitive.

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TheDudeMan an hour ago | parent | prev [-]

Don't worry, data centers are not going to space.

	▲	schiffern an hour ago \| parent [-]
		Exactly. Racks are going to space. For compute jobs that can be efficiently farmed out to individual racks, this is a nice way to stretch your PV manufacturing capacity to serve more chips (as long as launch costs aren't too high). For LLM training and other jobs that need an entire datacenter of racks working in parallel, that wouldn't be feasible to do in space with today's technology.

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ofjcihen 3 hours ago | parent | prev | next [-]

I was interested until I saw the picture for labor month was a clearly generated picture with protest signs saying “Workers Unit” instead of “Workers Unite”.

Does that mean everything in the site is bogus or low-effort? No, but it means I don’t want to potentially waste my time or be misled.

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MarkusQ an hour ago | parent | prev | next [-]

"Geothermal also has two key advantages over nuclear generation. Nuclear power plants are dependent upon a finite resource (uranium), and nuclear waste disposal is both controversial and costly. In contrast, geothermal generation depends on a virtually infinite source (heat generated in Earth’s interior), and there are no long-term waste issues."

1) Scientific consensus is that the Earth is also finite.

2) Also, the heat generated in the Earth's interior is...nuclear power.

3) Nuclear waste disposal is a political problem, not a technical one; it is "controversial" and "costly" precisely because it's used for these sorts of unserious comparisons.

I love the idea of geothermal, but this sort of nonsense has to be called out and shamed.

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Johnny_Bonk 6 hours ago | parent | prev [-]

I think i just saw Fervo delivered their 100MW facility a day ahead of schedule in 23 months.