5 ms·

I've always been curious why a cost-effective widespread implementation of geothermal energy has never been considered a holy grail of energy production, at lea

I've always been curious why a cost-effective widespread implementation of geothermal energy has never been considered a holy grail of energy production, at least not in the public debate. Much of the discussion is so focussed on nuclear fusion, which seems so much harder and less likely to be reliable.

polotics 11mo ago
There have been numerous trials that had to be stopped because of the triggered earthquakes... Geothermal is not so easy.
- microtherion 11mo ago
  Was going to mention that point: http://www.seismo.ethz.ch/en/knowledge/geothermal-energy-earthquakes/geothermal-energy-and-induced-earthquakes/ http://www.seismo.ethz.ch/en/knowledge/geothermal-energy-ear... The worst earthquake that was induced that way was 3.5, but given that one of the quakes happened in an area that had a catastrophic earthquake in the Middle Ages, some caution might be warranted: https://en.wikipedia.org/wiki/1356_Basel_earthquake https://en.wikipedia.org/wiki/1356_Basel_earthquake
- deleted 11mo ago
  [deleted]
__turbobrew__ 11mo ago
I think it mainly depends on how easy it is to access that energy. I went to Tuscany last year and to my surprise there were geothermal plants everywhere. I have never heard about these plants beforehand, but here they are in Italy quietly powering the countryside and heating greenhouses to grow basil all year around.
xienze 11mo ago
Probably because not everywhere on earth has the same easy access that Iceland has. The article mentions this: > There aren’t gates of Hell just anywhere. A kilometre below ground in Kamchatka is considerably hotter than a kilometre below ground in Kansas. There is also readily accessible geothermal energy in Kenya (where it provides almost fifty per cent of the country’s energy), New Zealand (about twenty per cent), and the Philippines (about fifteen per cent)—all volcanic areas along tectonic rifts. But in less Hadean landscapes the costs and uncertainties of drilling deep in search of sufficient heat have curtailed development.
- kragen 11mo ago
  It also explains why this is no longer a problem.
pjc50 11mo ago
Drilling is one of those things which used to be extremely expensive but has very gradually come down in price. Thanks, ironically, to the oil industry. It's unsexy because there's no "silver bullet" waiting in the wings. It's also quite hard to find suitably hot rocks suitably close to the surface. Focusing on fusion .. I think that's a legacy of 60s SF, when the fission revolution was still promising "energy too cheap to meter".
- tastyfreeze 11mo ago
  Plasma drilling is a recent development that looks promising for unlocking deeper wells for geothermal.
  - rini17 11mo ago
    Remains to be seen, it has serious trouble with water getting into the borehole.
- hodgehog11 11mo ago
  Many others here have talked about the difficulties of geothermal, which doesn't really get to the heart of my question: why the lack of hype around breaking down those difficulties? I appreciate that you took the time to comment on why it isn't so sexy, the SF argument probably has a lot to do with it.
- buu700 11mo ago
  To be fair, that promise of fission made sense from a purely scientific and mathematical perspective, before running into the practical realities of how its externalities interact with real-world politics. Fission is expensive because in practice it turns out we care quite a lot about proper waste management, non-proliferation, and meltdown prevention. In a world where anyone could just YOLO any reactor into production with minimal red tape, consequences be damned, fission energy would actually be extremely cheap. Hence the optimism around fusion. The promise of fusion is an actualization of last century's idealistic conception of fission. It can be a silver bullet for all intents and purposes, at least once it's established with a mature supply chain.
fuoqi 11mo ago
Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does not make economic sense compared to other energy sources.
- kragen 11mo ago
  While it's true that a geothermal plant is a limited battery powered by hot rock, that doesn't mean it doesn't make economic sense compared to other energy sources.
- piva00 11mo ago
  I think OP meant technology for drilling becoming cheaper rather than the near-surface availability of it.
- dns_snek 11mo ago
  > In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!) Ground-source heat pumps extract about 1000 times more power from ground loops, where does the difference come from?
  - bluGill 11mo ago
    A number of sources. Often the air above - ground source relies on the ground being the average temperature of the year round air once you get deep. They also tend to run in heating mode half the year, and cooling mode the other half.
  - kragen 11mo ago
    Ground-source heat pumps are irrelevant to geothermal energy sources, and it's unfortunate that the article mentioned them. Ground-source heat pumps are just storing heat from the air during the summer and retrieving it during the winter.
6510 11mo ago
There is a crazy amount of energy available everywhere but it is not in the interest of the very powerful very wealthy existing players. This isn't some grand CONSPIRACY. For example oil companies may construct energy investment portfolios that would quite sensibly acquire promising energy related research. They do a simple cost benefit analysis then chose to modestly further research it or shelve it. They turn it into valuable pieces of paper that accumulate value over time. What is there for them not to like about it? I like how David Hamel put it: We live in this thin sliver on the surface of the planet where it is reasonably peaceful. This is the tranquility! It's a good thing! If you go up or down by a mere few miles there is so much energy it kills you.
nickcw 11mo ago
Why not is explained in David McKay's book Sustainable Energy - without the hot air https://www.withouthotair.com/c16/page_96.shtml https://www.withouthotair.com/c16/page_96.shtml The problems are that rock isn't a good conductor of heat, so once you've cooled a bit down, you have to wait for it to warm up. Warming only happens very slowly at the rate of < 50mW / m² which limits the amount of power you can get out.
- hodgehog11 11mo ago
  That's a really good point, and it does take the wind out of the sails. Isn't it possible that eventually we could drill deeper?
- cameldrv 11mo ago
  Couldn't you frac the rock like they do with oil and gas drilling or have a branching borehole?
  - kragen 11mo ago
    Yes, that's what this article is about.
hackeraccount 11mo ago
Harder absolutely but "less likely to be reliable"? If economically viable fusion was "cracked" what would the nature of it's unreliability even be?
- hcknwscommenter 11mo ago
  all the machinery used to obtain and maintain an economically viable fusion reaction. Having worked with particle accelerators and synchrotron rings, I'll tell you that stuff breaks down all the time.
- pfdietz 11mo ago
  The reactor breaking and taking a very long time to repair because the repairs would have to be done remotely, with robots. The structure becomes too activated for people to go inside, even after the reactor is shut off. The reactor breaks because it's a large device operated at high stresses (power/area, neutron loading). There are many components and joints that can fail. BTW, this means fusion will be expensive, because getting all those components to be reliable right off the bat becomes expensive. No tiny cracks in the welds means expensive quality control.
Iwan-Zotow 11mo ago
Power flow is in general very low - ca 50-60 mW/sq.m
roadside_picnic 11mo ago
> a holy grail of energy production Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production? It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a smaller part of total energy usage than most people imagine. But any serious discussion of renewable energy should be careful not to make this very significant error. The Lawrence Livermore National Laboratory publishes a great diagram of US energy use: https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/energy-2023-united-states.png https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/e...
- jimbokun 11mo ago
  What does "Rejected Energy" mean in that graph? Great chart, by the way.
  - philipkglass 11mo ago
    Rejected energy means energy that is lost as waste heat without performing any work first. For example, a coal fired power plant may generate 3 megajoules of thermal energy from coal combustion but only deliver 1 megajoule of it as electricity. The other 2 megajoules are lost as useless waste heat. The 1 megajoule of useful electricity is also ultimately dissipated as low grade heat, but it can do work first (like generating light, or pumping water uphill).
  - floatrock 11mo ago
    Only about 30% of the energy in gasoline is converted to useful work in a gasoline car (the 'make metal box go forward' part). The remaining 70% is Rejected Energy (the steam you see going out the tail pipe in winter). Which (not sure if you did this intentionally or accidentally) brings up an interesting point on the parent comment and the LLNL sankey: > It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). That "global energy consumption" figure includes a lot of Rejected Energy going out tailpipes and smoke stacks turning burnables into electricity. A secret bonus of wind and solar is if you produce electricity without burning things, you actually decrease the energy demand! If you're not losing 70% of your energy consumption to the Rejected category, you suddenly need a lot less total energy.
jamescrowley 11mo ago
Until recently, the geographical locations where geothermal is feasible and economic was very limited. Ironically it is tech from fracking/shale gas that is starting to open up a far wider range of possible sites at lower cost.

polotics 11mo ago

There have been numerous trials that had to be stopped because of the triggered earthquakes... Geothermal is not so easy.

microtherion 11mo ago
Was going to mention that point: http://www.seismo.ethz.ch/en/knowledge/geothermal-energy-earthquakes/geothermal-energy-and-induced-earthquakes/ http://www.seismo.ethz.ch/en/knowledge/geothermal-energy-ear... The worst earthquake that was induced that way was 3.5, but given that one of the quakes happened in an area that had a catastrophic earthquake in the Middle Ages, some caution might be warranted: https://en.wikipedia.org/wiki/1356_Basel_earthquake https://en.wikipedia.org/wiki/1356_Basel_earthquake
deleted 11mo ago
[deleted]

__turbobrew__ 11mo ago

I think it mainly depends on how easy it is to access that energy. I went to Tuscany last year and to my surprise there were geothermal plants everywhere. I have never heard about these plants beforehand, but here they are in Italy quietly powering the countryside and heating greenhouses to grow basil all year around.

xienze 11mo ago

Probably because not everywhere on earth has the same easy access that Iceland has. The article mentions this: > There aren’t gates of Hell just anywhere. A kilometre below ground in Kamchatka is considerably hotter than a kilometre below ground in Kansas. There is also readily accessible geothermal energy in Kenya (where it provides almost fifty per cent of the country’s energy), New Zealand (about twenty per cent), and the Philippines (about fifteen per cent)—all volcanic areas along tectonic rifts. But in less Hadean landscapes the costs and uncertainties of drilling deep in search of sufficient heat have curtailed development.

kragen 11mo ago
It also explains why this is no longer a problem.

pjc50 11mo ago

Drilling is one of those things which used to be extremely expensive but has very gradually come down in price. Thanks, ironically, to the oil industry. It's unsexy because there's no "silver bullet" waiting in the wings. It's also quite hard to find suitably hot rocks suitably close to the surface. Focusing on fusion .. I think that's a legacy of 60s SF, when the fission revolution was still promising "energy too cheap to meter".

tastyfreeze 11mo ago
Plasma drilling is a recent development that looks promising for unlocking deeper wells for geothermal.
- rini17 11mo ago
  Remains to be seen, it has serious trouble with water getting into the borehole.
hodgehog11 11mo ago
Many others here have talked about the difficulties of geothermal, which doesn't really get to the heart of my question: why the lack of hype around breaking down those difficulties? I appreciate that you took the time to comment on why it isn't so sexy, the SF argument probably has a lot to do with it.
buu700 11mo ago
To be fair, that promise of fission made sense from a purely scientific and mathematical perspective, before running into the practical realities of how its externalities interact with real-world politics. Fission is expensive because in practice it turns out we care quite a lot about proper waste management, non-proliferation, and meltdown prevention. In a world where anyone could just YOLO any reactor into production with minimal red tape, consequences be damned, fission energy would actually be extremely cheap. Hence the optimism around fusion. The promise of fusion is an actualization of last century's idealistic conception of fission. It can be a silver bullet for all intents and purposes, at least once it's established with a mature supply chain.

fuoqi 11mo ago

Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does not make economic sense compared to other energy sources.

kragen 11mo ago
While it's true that a geothermal plant is a limited battery powered by hot rock, that doesn't mean it doesn't make economic sense compared to other energy sources.
piva00 11mo ago
I think OP meant technology for drilling becoming cheaper rather than the near-surface availability of it.
dns_snek 11mo ago
> In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!) Ground-source heat pumps extract about 1000 times more power from ground loops, where does the difference come from?
- bluGill 11mo ago
  A number of sources. Often the air above - ground source relies on the ground being the average temperature of the year round air once you get deep. They also tend to run in heating mode half the year, and cooling mode the other half.
- kragen 11mo ago
  Ground-source heat pumps are irrelevant to geothermal energy sources, and it's unfortunate that the article mentioned them. Ground-source heat pumps are just storing heat from the air during the summer and retrieving it during the winter.

6510 11mo ago

There is a crazy amount of energy available everywhere but it is not in the interest of the very powerful very wealthy existing players. This isn't some grand CONSPIRACY. For example oil companies may construct energy investment portfolios that would quite sensibly acquire promising energy related research. They do a simple cost benefit analysis then chose to modestly further research it or shelve it. They turn it into valuable pieces of paper that accumulate value over time. What is there for them not to like about it? I like how David Hamel put it: We live in this thin sliver on the surface of the planet where it is reasonably peaceful. This is the tranquility! It's a good thing! If you go up or down by a mere few miles there is so much energy it kills you.

nickcw 11mo ago

Why not is explained in David McKay's book Sustainable Energy - without the hot air https://www.withouthotair.com/c16/page_96.shtml https://www.withouthotair.com/c16/page_96.shtml The problems are that rock isn't a good conductor of heat, so once you've cooled a bit down, you have to wait for it to warm up. Warming only happens very slowly at the rate of < 50mW / m² which limits the amount of power you can get out.

hodgehog11 11mo ago
That's a really good point, and it does take the wind out of the sails. Isn't it possible that eventually we could drill deeper?
cameldrv 11mo ago
Couldn't you frac the rock like they do with oil and gas drilling or have a branching borehole?
- kragen 11mo ago
  Yes, that's what this article is about.

hackeraccount 11mo ago

Harder absolutely but "less likely to be reliable"? If economically viable fusion was "cracked" what would the nature of it's unreliability even be?

hcknwscommenter 11mo ago
all the machinery used to obtain and maintain an economically viable fusion reaction. Having worked with particle accelerators and synchrotron rings, I'll tell you that stuff breaks down all the time.
pfdietz 11mo ago
The reactor breaking and taking a very long time to repair because the repairs would have to be done remotely, with robots. The structure becomes too activated for people to go inside, even after the reactor is shut off. The reactor breaks because it's a large device operated at high stresses (power/area, neutron loading). There are many components and joints that can fail. BTW, this means fusion will be expensive, because getting all those components to be reliable right off the bat becomes expensive. No tiny cracks in the welds means expensive quality control.

Iwan-Zotow 11mo ago

Power flow is in general very low - ca 50-60 mW/sq.m

roadside_picnic 11mo ago

> a holy grail of energy production Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production? It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a smaller part of total energy usage than most people imagine. But any serious discussion of renewable energy should be careful not to make this very significant error. The Lawrence Livermore National Laboratory publishes a great diagram of US energy use: https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/energy-2023-united-states.png https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/e...

jimbokun 11mo ago
What does "Rejected Energy" mean in that graph? Great chart, by the way.
- philipkglass 11mo ago
  Rejected energy means energy that is lost as waste heat without performing any work first. For example, a coal fired power plant may generate 3 megajoules of thermal energy from coal combustion but only deliver 1 megajoule of it as electricity. The other 2 megajoules are lost as useless waste heat. The 1 megajoule of useful electricity is also ultimately dissipated as low grade heat, but it can do work first (like generating light, or pumping water uphill).
- floatrock 11mo ago
  Only about 30% of the energy in gasoline is converted to useful work in a gasoline car (the 'make metal box go forward' part). The remaining 70% is Rejected Energy (the steam you see going out the tail pipe in winter). Which (not sure if you did this intentionally or accidentally) brings up an interesting point on the parent comment and the LLNL sankey: > It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). That "global energy consumption" figure includes a lot of Rejected Energy going out tailpipes and smoke stacks turning burnables into electricity. A secret bonus of wind and solar is if you produce electricity without burning things, you actually decrease the energy demand! If you're not losing 70% of your energy consumption to the Rejected category, you suddenly need a lot less total energy.

jamescrowley 11mo ago

Until recently, the geographical locations where geothermal is feasible and economic was very limited. Ironically it is tech from fracking/shale gas that is starting to open up a far wider range of possible sites at lower cost.