I worked on geothermal control systems a decade or so back. There are some less obvious applications for geothermal that reduce electric use (as opposed to generating electricity).
The systems I worked on were for cooling larger structures like commercial greenhouses, gov installations and mansions. 64° degree water would be pumped up from 400' down, run thru a series of chillers (for a/c) and then returned underground - about 20° or 25° warmer.
I always thought this method could be used to provide a/c for neighborhoods, operated as a neighborhood utility. I've not seen it done tho. I've seen neighborhood owned water supplies and sewer systems; it tells me the ownership part seems feasible.
> I always thought this method could be used to provide a/c for neighborhoods, operated as a neighborhood utility. I've not seen it done tho. I've seen neighborhood owned water supplies and sewer systems; it tells me the ownership part seems feasible.
I keep thinking this would be a great municipal code change: any time the roads are being built or ripped up for water/sewer maintenance, put in a ground loop and subsidize household connections for heat pumps so instead of having to deal with the marginal difference between 20℉ winter air you'd be working with 50-60℉ ground temperatures.
> The systems I worked on were for cooling larger structures like commercial greenhouses, gov installations and mansions. 64° degree water would be pumped up from 400' down, run thru a series of chillers (for a/c) and then returned underground - about 20° or 25° warmer.
I read this several times in the context of _geothermal_ energy, and had no clue what you were talking about.
Then I realised, you must be an American and use 'freedom units', coupled with a misunderstanding of what geothermal means.
Oh, Fervo Energy again. They're trying to IPO, hence the hype.
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Here is an article that is a bit old but discusses the start of things [1]. It would be a bit ironic if fracking tech helped get us further from using natural gas. I think the reality will be if this gets established we will see rapid improvement as scale comes on line so if it is remotely economical now it will be massively better in 5-10 years. Of course the 'if' applies.
According to google, this would be almost 30% of total US energy production (135gw-150gw) and nearly 5% of total US energy consumption.
But what is the "breakthrough" if there is one? The article doesn't really suggest any breakthrough that is unlocking this potential energy? Or maybe I'm looking for a technological breakthrough where there isn't one.
It’s a stupid ploy by oil drillers to try and expand their existing capex to something more future proof. Their theory is to randomly frack the ground and hope superheated water shows up there. It’s probably just going to end up ruining existing groundwater sources.
They're adapting fracking techniques to use for geothermal, which opens up many more sites. Historically geothermal has had limited potential, and the best sites have already been developed. So geothermal + fracking creates a lot more viable land.
Traditional geothermal is you dig a really deep well and get a geyser of hot water or steam to come up.
Fervo is doing "Enhanced" or "Engineered" geothermal where you dig two wells: an injection and an extraction well. You frack the rock in between, creating lots of small channels for water to flow between them. The water absorbs the heat from the rocks as its circulating from the injection well to the extraction well.
The kind of rock that's good at this heat transfer is different from shale rock that oil & gas frackers have experience with... it's harder, less porous, not partial-dino-juice. So they're taking a lot of the same core concepts from the oil & gas industry (horizontal drilling, geology simulations, etc), but their IP is in adopting the techniques to work with geothermal-favorable rock.
Another interesting concept I heard Fervo researching: this kind of geothermal is not "baseload" style power, so there's a few tricks they can do to get better cost efficiency and peaker-like or battery-like behavior. Remember the two wells that form the circulation loop: injection and extraction? Well, you need pumps on both sides (remember, this isn't "geyser-style" geothermal where natural pressure and geology do all the work). Pumps take energy to run, something like 20-30% of the overall extraction output (you put a unit of energy in to run the pumps and you get 3-5 units of energy back out the other end). Not great, not terrible either... it's an energy return comparable to solar and wind. But what you can do is run the injection pump when power prices are low (ie when there's an excess of solar on the grid), pressurize all your fracked channels underground (the reservoir), and then when grid prices rise in the evening you run just the extraction pump to pull out the pre-heated, pre-pressurized water. You're still at a 3-5x energy return, but the time-shifting has made the cost multiplier more favorable.
My understanding is it's still in research phase, but Fervo is piloting this technique. Like another thread said, they're pre-IPO now, so they've been flooding the renewables media with all these stories. They filed an S-1 recently, but always read the eventual S-3 before considering your investment options blahblahblah.
this looks like a search for fluffy money durring an energy crisis.
Turbines are completly mature, and nothing dealing with some new deap drilling breakthrough or heat exhanger advancement, or more efficient and durable pumps, crittical CO², or H²O ?, not yet.
Existing geothermal plants use the same generation technology as a coal plant, but use near surface heat assosiated with volcanoes and hot springs, and there is a distinct limit on more of that.
With all the exotic drilling tech making fracking work, it seems like geothermal is a natural pivot since much of the challenge is controlling the cost of drilling deeply.
The Casa Diablo geothermal facility in the eastern Sierra Nevada of California has been a success. I also remember reading years back about ideas surrounding how to extract energy from Yellowstone both to provide clean energy but also to decrease risk of another massive explosion. If I recall they were proposing digging a massive horizontal tunnel to come in deep and extract heat without compromising the roof.
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[ 3.1 ms ] story [ 53.4 ms ] threadThe systems I worked on were for cooling larger structures like commercial greenhouses, gov installations and mansions. 64° degree water would be pumped up from 400' down, run thru a series of chillers (for a/c) and then returned underground - about 20° or 25° warmer.
I always thought this method could be used to provide a/c for neighborhoods, operated as a neighborhood utility. I've not seen it done tho. I've seen neighborhood owned water supplies and sewer systems; it tells me the ownership part seems feasible.
I keep thinking this would be a great municipal code change: any time the roads are being built or ripped up for water/sewer maintenance, put in a ground loop and subsidize household connections for heat pumps so instead of having to deal with the marginal difference between 20℉ winter air you'd be working with 50-60℉ ground temperatures.
I read this several times in the context of _geothermal_ energy, and had no clue what you were talking about.
Then I realised, you must be an American and use 'freedom units', coupled with a misunderstanding of what geothermal means.
Here's a more realistic evaluation of Fervo.[1]
[1] https://www.latitudemedia.com/news/what-fervos-approach-says...
[1] (2023) https://time.com/6302342/fervo-fracking-technology-geotherma...
https://www.opb.org/article/2025/10/06/super-hot-rocks-geoth...
But what is the "breakthrough" if there is one? The article doesn't really suggest any breakthrough that is unlocking this potential energy? Or maybe I'm looking for a technological breakthrough where there isn't one.
Traditional geothermal is you dig a really deep well and get a geyser of hot water or steam to come up.
Fervo is doing "Enhanced" or "Engineered" geothermal where you dig two wells: an injection and an extraction well. You frack the rock in between, creating lots of small channels for water to flow between them. The water absorbs the heat from the rocks as its circulating from the injection well to the extraction well.
The kind of rock that's good at this heat transfer is different from shale rock that oil & gas frackers have experience with... it's harder, less porous, not partial-dino-juice. So they're taking a lot of the same core concepts from the oil & gas industry (horizontal drilling, geology simulations, etc), but their IP is in adopting the techniques to work with geothermal-favorable rock.
Another interesting concept I heard Fervo researching: this kind of geothermal is not "baseload" style power, so there's a few tricks they can do to get better cost efficiency and peaker-like or battery-like behavior. Remember the two wells that form the circulation loop: injection and extraction? Well, you need pumps on both sides (remember, this isn't "geyser-style" geothermal where natural pressure and geology do all the work). Pumps take energy to run, something like 20-30% of the overall extraction output (you put a unit of energy in to run the pumps and you get 3-5 units of energy back out the other end). Not great, not terrible either... it's an energy return comparable to solar and wind. But what you can do is run the injection pump when power prices are low (ie when there's an excess of solar on the grid), pressurize all your fracked channels underground (the reservoir), and then when grid prices rise in the evening you run just the extraction pump to pull out the pre-heated, pre-pressurized water. You're still at a 3-5x energy return, but the time-shifting has made the cost multiplier more favorable.
My understanding is it's still in research phase, but Fervo is piloting this technique. Like another thread said, they're pre-IPO now, so they've been flooding the renewables media with all these stories. They filed an S-1 recently, but always read the eventual S-3 before considering your investment options blahblahblah.
Turbines are completly mature, and nothing dealing with some new deap drilling breakthrough or heat exhanger advancement, or more efficient and durable pumps, crittical CO², or H²O ?, not yet. Existing geothermal plants use the same generation technology as a coal plant, but use near surface heat assosiated with volcanoes and hot springs, and there is a distinct limit on more of that.
Long Valley Caldera Geothermal Area | Open Energy Information https://share.google/5DvljMhL3EVMDeIAL
IT'S HARD TO IMAGINE LESS IDIOTIC WAY OF ENERGY PRODUCTION