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.
In the nordics it is common to have ground source heat pumps (brine in closed circuit pipe or bore hole) that are run backwards in summer to cool the house while actually assisting in storing heat back in the ground to extract in the winter. It’s a bit like regenerative breaking on electric cars.
No it's not. It exists but it's certainly not common for individual dwelling to use ground source heat pumps, at least in Norway. It is more common in Sweden[1] but still far less common than air source and over 90% of heat pump installations in Norway are air source[2].
The only ground source installations I can think of in Norway serve large office buildings and similar. The largest heat pump installation I know of in Norway is actually a third kind: water source[3]. It takes heat from the Drammen river to provide heat for a district heating system and for keeping the town centre clear of ice in the winter as well as supplying the new hospital with heat.
I imagine that the rest of the Nordic region is similar.
If by Nordics you mean Norway, Sweden and Finland, then the most correct way to say would be that ground source heat pumps for redidential heating are (very) common in Sweden and Finland, especially in newer and larger buildings. Norway is somewhat different in energy and climate perspective than its eastern neighbours.
The biggest reason to not install ground source heat pump is high installation cost. This means that it makes more sense for larger residential buildings. Also If you have district heating available then this might be more economical in the long run.
There was a new in 1988 house in Champaign, Illinois, USA that used the same system, and i mention that because it was a normal modern house, and it's the only one i've heard of with that system.
Our house came with one and we upgraded the unit a few years ago. It's very efficient in terms of units of energy consumed, but in my area of the world gas is significantly cheaper than electricity so it ends up being expensive to run.
That said, we will install solar at some point and then it'll be "free" HVAC.
There's a pretty significant upfront cost in getting them drilled, and many homes need the vertical drilling if they don't have sufficient yard space for a horizontal system. It gets harder if you have your own septic drain field too, as that will complete for yard space.
The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option though.
I paid about EUR 4500 for a 114 meter drill hole including installation of brine (ethanol in my case actually) and removal of spoils. My 8kW heat+water pump was about EUR 7000.
I can spec out a gas burner for about EUR 4000 and a central AC for EUR 5000, but I bet the efficiency of the ground source heater would quickly trump the cost of buying gas regularly.
Although if you needed a new septic field, I would think ground source thermal would be significantly deeper than a drain field which is only like a foot or so down so you could stack them.
Air source heat pumps are insanely more efficient and just plain better these days too. It used to be that if the air was below 40F you couldn't heat your house with a heat pump. Now, you can heat your house even when it's -10F
If you can tolerate the price, I am _confident_ that you will pretty much always have better results using the Earth as your thermal exhaust, because you don't have to dig very far to find a large region that's pretty much always at 50 F.
The price of things - heat pumps and alternatives - in different regions - even different regions within the US - varies by what people are prepared to pay not what they cost to produce.
The nordics have traditionally had cheap heat pumps whereas piped gas is only in the biggest cities and I’ve never seen bottled gas in the countryside. The competitor used to be cheap electricity and wood. Ground source heat pumps for rural install have been priced to compete with wood.
In the US the market could be shaped by regulation and taxation etc. It’s the choice of the US to have cheap fossil fuels and not embrace tech instead.
> Air source heat pumps are insanely more efficient
Citation needed?
Efficient how? I'm sure a heat pump designed for a narrow range of input temperatures AND working with water which can transport a lot more heat should easily be more efficient.
I assuming he means insanely more efficient than they used to be, not more efficient than ground-source (awkward wording though). I suppose they can also be described as more efficient in installation time, cost and equipment than ground source, but clearly not in operating efficiency.
Shallow geothermal works fine for heating. And you can use the ground as a heat sink. But if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells. Fervo Energy claims to have found 270C at 3350 meters well depth. That's progress.
> But if you want to generate power, you need to get down to where temperatures can boil water.
Why is that the case? Can't you go down to where it's like 70-80 deg C and close the gap using heat pumps? Yes, you need to put some energy in, but I would expect that the whole process would still be energy-positive at some temperature that's lower than 100C?
"New Zealand has an abundant supply of geothermal energy because we are located on the boundary between two tectonic plates. ... Total geothermal electricity capacity in New Zealand stands at over 900 MW, making us the fifth largest generator of geothermal in the world. It has been estimated that there is sufficient geothermal resource for another 1,000 MW of electricity generation."
That's not all that much. That total would be about equal to the 75th largest nuclear plant in the world.
Good sites where high temperatures are near the surface are rare. California has a few, but no promising locations for more.
May not be much in world terms but here in NZ national demand maxes out at around 5.5GW so bringing another GW on stream would be quite handy. Most of the geothermal is a lot closer to Auckland* than our hydro is so so that would be another positive aspect.
* Auckland has 25% of the population so a corresponding amount of energy has to be pushed its way.
We don’t have many people. It gets worse’s though, we burn coal and are looking to fund a gas terminal. We have abundant other ways of generating power and subsidise an aluminium smelter for some reason.
There are also places in the US with boiling water at the surface. I live near one of those places so always curious about geothermal. There's a spot near my house in a creek bed where snow always melts even in deep winter so apparently I have some potential heat source. Our well water is cold though.
I think this looks interesting, but still very early stage. The “150 GW revolution” sounds more like theoretical potential, not something we will see soon in real deployment.
Main problems: drilling is still expensive, managing induced seismic activity is not trivial, permitting can take long time, and you also need transmission infrastructure. Also not yet proven that companies like Fervo can scale this in reliable and low-cost way.
Nope. To efficiently tap geothermal energy, you need to boil something but not necessarily water. Isopentane, for example, boils at 28º at standard pressure, so they pressurize the secondary loop to raise the boiling point close to whatever the primary loop temperature is.
The idea that geothermal only works well at steam temperatures is outdated 20th-century thinking.
Yes, the efficiency is worse, but as is also the case for solar power you need to get used to not caring much about efficiency. It is nuclear energy where the primary side is provided free of charge. The Carnot efficiency is almost without relevance.
In geothermal there is still a lot of interest in efficiency and exploring different working fluids because binary systems now have efficiencies of 10-20%. That is why you see companies like Sage Geosystems working on developing / deploying supercritical CO2 turbines to try and boost practical power densities.
I'm too zonked to pick out the method from the article - but I'll offer that geo methods can be region specific. What I described fits the SE US, with our 13 month summers and abundant underground water.
I don't know how economical that is, but just as an anecdote - the town I'm from in Poland has district heating to all single family homes, town of about 20k people. And coincidentally, I now live in the UK and a new estate near me has district heating to all the houses they are building, not apartment blocks. So it must make some sense to someone, or they wouldn't be outfitting 100+ houses this way.
It’s uneconomical in an already built out area or a non central planned economy, and also the US is special case since we have dirt cheap natural gas that is used for heating.
Digging up streets to run distribution lines, running service drops to every existing house, installing a heat exchanger and valves in every house is astronomically expensive given the amount of energy used by a single residence.
If you’re building out a new neighborhood on a greenspace plot, installing the district heating/cooling piping is much cheaper since you’re already laying electric, water, sewer, and mane gas lines.
At least in parts of Eastern Europe (especially the former GDR) district heating systems were introduced as a response to the oil crises of the 70s, resulting price shocks and the transport of coal to households being very labor and resource incentive [1].
Sure you do. Think about it. Its just drilling a hole and making electricity from the heat. We have been able to do this for a very long time. So if people aren't really doing it much, its not economical. If it was now becoming economical, the article would describe some new way of doing it that makes it economical. The article doesn't, so you "know" it isn't.
PS This has been tried many time, it only works in very specific situations, usually places where building a full PP doesn't make sense or where you are making a lot of electricity for some other purpose (mining usually).
Sometimes district heating and electricity generation does combine though:
> Wärtsilä’s combined power generation and heat recovery plant offering comprises solutions for combined heat and power (CHP) including dynamic district heating (DDH), district cooling and power (DCAP) and trigeneration for applications that require both heating and cooling.
Not always, but as the sibling noted, there are plenty of combined heat and power plants. They recover as much of the energy as possible from the exhaust gas streams and run pretty efficiently.
Heat pumps require a specific temperate differential to work. So they work in zones with are a bit hotter or colder than you would like and so require moderate amounts of heating or cooling. They don't work in temperate zones nor in very hot or cold places. So Santa Fe or Minneapolis for example they work but Mexico City or San Francisco they don't. If you are in a place where they work and that isn't too dense or has earthquakes, go for it. If not, don't. There are businesses that will help you understand when they do and don't make sense. Those businesses don't sell heat pumps though (the businesses that sell things will almost always tell you it works, even when it doesn't, for example PV in the UK doesn't work).
I’ve never heard a claim that heat pumps won’t work well in a climate like San Francisco and, from looking at the annual temperature patterns, it seems like both air source and ground source heat pumps should work extremely well as they do in the “shoulder seasons” here in New England.
Heat pumps have gotten a lot better, you need a pretty extreme climate for them to start to struggle, even the air-source ones.
(And PV works well enough in the UK for it to be a no-brainer to put on residentials roofs, which is on the whole the most expensive way to deploy it. Though this is in large part due to the way that it competes with retail prices and not wholesale prices)
The water at these temperature / depths has a lot of dissolved salts and minerals so it's not (human / ag) usable. Modern designs are closed loop systems where production wells bringing the hot water to the surface go through a heat exchanger to a different working fluid to drive the turbine and then is re-injected back into the reservoir. There is consumptive water use for fracking the reservoirs in these types of enhanced geothermal systems, but beyond that it's more water redistribution in the area around the well systems where re-injection and production lead to different pressurization from pumping / natural ground water replenishment rates.
> One of the problems with the data center boom is its use of fresh water. How does geo-thermal plants use water and how much?
Baring leaks, ground source heat pump geo will consume no water at all. Water is pumped from one layer of the aquifer and is returned to a slightly higher layer.
Oh, Fervo Energy again. They're trying to IPO, hence the hype.
Wikipedia's warning: This article reads like a press release or a news article and may be largely based on routine coverage. (February 2026)
This article may have been created or edited in return for undisclosed payments, a violation of Wikipedia's terms of use. It may require cleanup to comply with Wikipedia's content policies, particularly neutral point of view.
This isn’t really an evaluation of the company, just explaining how they had to use different financing approaches as they grew and derisked their technology (which makes sense).
Compared to some other new approaches for getting clean base load power, it seems like they’ve been pretty grounded and methodical.
They're way ahead of the microwave drilling people.
There's no reason why this shouldn't work. But they've been at it for 9 years, with considerable funding, and it doesn't really work yet. That's a concern.
> There's no reason why this shouldn't work. But they've been at it for 9 years, with considerable funding, and it doesn't really work yet. That's a concern.
It does work. They've had a pilot project producing 3 megawatts since 2023. But scaling takes a lot of time and money, particularly when it's something new and you have to go through a lot of operational learning.
Shale took something like 30 years to become a thing. 9 years is nothing in the energy space.
It does work technically I think it is still an open question if it can work economically. There are issues of commercially viable flow rates / thermal decline rates that are harder physical limits you run up against and the pilot design doesn't address. In human timescale terms it's more like heat mining rather than renewable heat due to thermal depletion rate vs replenishment rate. These systems have a targeted lifetime of ~20-30 years and net power will decline over this timespan.
Geothermal has had the same problem for its entire history. That problem is that the water being heated goes through the ground (not in a pipe) to "gather" more energy. But this means that when the water comes back up, it has a lot of weird salts in it (and other things). Those salts cause corrosion, lots and lots of corrosion, far more than even a maritime environment. So the plant needs to be shutdown a lot of the time for repairs. And that's what makes it uneconomical. Also, the salts often contain things that require special handling which also increases costs.
PS This is why geothermal works in Iceland where there is so much geothermal heat they can use pipes. In CA, they can't so it doesn't work there.
Fervo uses engineered reservoirs in granitic basement rock so this is less of an issue. Hot rock in a working fluid can still dissolve silicates out of the granite and lead to scaling / degradation of the flow rates through the reservoir and that is a risk but chemical anti scaling treatments are used to reduce this.
CA has the worlds largest geothermal power complex in the Geysers. That one field produces an equivalent amount of power as all the geothermal in Iceland and there are others.
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.
There isn't one. They are trying to politically pressure a utility to build some geothermal plant. But utilities have engineers who will tell their bosses that this plan doesn't work. So the companies selling the geothermal plant are trying to politically pressure the utility to do yet another thing that they know won't work. PG&E for example has several geothermal plants which have been economic disasters and were and are being shutdown.
The core breakthroughs were working with partners to develop PDC bits that enable high rates of penetration in drilling out these horizontal wells in high temp granitic rock and then demonstrating plug / perf fracture networks that have a high engineered permeability in these source rocks to support economical flow rates and heat transfer. These were considerable advances over previous efforts.
There will be other learning by doing advances in how you structure your power plant design to take advantage of these to make practical long term power production possible (well spacing and injection / production placement / flow rate and temperature decline management).
> Several companies are now building upon existing techniques for accessing geothermal resources by integrating enhanced geothermal systems (EGS) into operations. While conventional geothermal systems produce energy using hot water or steam, pumped from naturally occurring hydrothermal reservoirs trapped in rock formations underground, EGS use innovative drilling technologies, such as those used in fracking operations, to drill horizontally and create hydrothermal reservoirs where they don’t currently exist.
Drilling horizontally doesn’t magically reduce the depth, nor the problem that drilling in to hot rock is like drilling in to plasticine, at least for temperatures worth working with.
In traditional fault hosted (not magmatic) geothermal the convection of the water up the fault brings the thermal energy closer to the surface where drilling depths are economical. This convection heats the surrounding rock and over hundred thousand - million of years brings the background temperature around a large volume at depth surrounding these systems considerably above traditional background geothermal gradients. By drilling into a much larger volume of impermeable hot rock surrounding a very small permeable fault hosted section you can considerably enhance the power potential of a traditional fault hosted geothermal system (the E in EGS). That is what Fervo is doing and why their projects are situated right next to traditional geothermal power plants.
The assumption is that if you can increase drilling efficiencies enough then you don't even need a fault hosted or similar system to bring that energy close to the surface, you can just drill down deep enough to get at similar temperatures. That is a big assumption in the economics.
EGS has been around for at least 15 years. See AltaRock Energy as an example (I’m sure there are others). They started almost 20 years ago.
https://en.wikipedia.org/wiki/AltaRock_Energy
No. Current geothermal projects need very specific geology to work, its very rare which is why geothermal is such a small blip in the overall energy picture. Enhanced Geothermal Systems (EGS), the technique Fervo is using, can create the conditions to be able to generate electricity. The hope is this will greatly expand the number of projects that can be developed.
My understanding is that it's due to better drilling techniques. The industry learned a fair bit from fracking and they're learning more from experience as they apply it to geothermal.
No particular breakthrough, but there's a learning curve and they learn more as they do more. Other industries sometimes work that way, too.
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.
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.
Solar and wind, with battery storage, can get you to say 90%, and then you only need 10% from other sources like geothermal and nuclear to fully decarbonize.
Newberry Volcano is too good to be true in that there are few (outside of Yellowstone) equivalent sources of geothermal awesomeness at similar depths in the USA. Good for research bad for generalization of drilling costs to hit similar temperatures. There are federal protections for geothermal drilling anywhere near Yellowstone.
Cost is like 90-99% of what matters. Last year, China installed 300GW of new renewables and 0GW of geothermal, despite geothermal being "an inexhaustible 24/7 production capable".
Geothermal will compete with solar if they can get the cost low enough. I hope they succeed!
These are typically representative of cost performance per watt of one part of a more complex deployed energy system. Things like the aluminum / steal for the container / framing, copper / aluminum for the transmission and wiring, land and labor for installation decline at much less aggressive rates or increase over time.
In almost all pareto optimal least cost energy system models that I've seen, high penetration of solar, wind, batteries plus some minority amount of (clean) baseload power is the most capital efficient energy system.
You know how the United Arab Emirates are known as the Emirates, how the United Mexican Sates are known as Mexico and how the United States of America is known as America? Are you unfamiliar with what synecdoche is?
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.
In the nordics it is common to have ground source heat pumps (brine in closed circuit pipe or bore hole) that are run backwards in summer to cool the house while actually assisting in storing heat back in the ground to extract in the winter. It’s a bit like regenerative breaking on electric cars.
No it's not. It exists but it's certainly not common for individual dwelling to use ground source heat pumps, at least in Norway. It is more common in Sweden[1] but still far less common than air source and over 90% of heat pump installations in Norway are air source[2].
The only ground source installations I can think of in Norway serve large office buildings and similar. The largest heat pump installation I know of in Norway is actually a third kind: water source[3]. It takes heat from the Drammen river to provide heat for a district heating system and for keeping the town centre clear of ice in the winter as well as supplying the new hospital with heat.
I imagine that the rest of the Nordic region is similar.
See:
[1] http://publications.jrc.ec.europa.eu/repository/bitstream/JR...
[2] https://www.sciencedirect.com/science/article/pii/S221313882...
[3] https://energiteknikk.net/2023/11/drammen-fjernvarme-storst-...
If by Nordics you mean Norway, Sweden and Finland, then the most correct way to say would be that ground source heat pumps for redidential heating are (very) common in Sweden and Finland, especially in newer and larger buildings. Norway is somewhat different in energy and climate perspective than its eastern neighbours.
The biggest reason to not install ground source heat pump is high installation cost. This means that it makes more sense for larger residential buildings. Also If you have district heating available then this might be more economical in the long run.
In Finland around 50% of new single-family homes use ground source heat pumps. So it's definitely popular here.
3 schools in my neighborhood (barneskole, ungdomsskole & videregående) all use ground source heat pumps.
There was a new in 1988 house in Champaign, Illinois, USA that used the same system, and i mention that because it was a normal modern house, and it's the only one i've heard of with that system.
It seems so smart.
It's expensive. A relative has one in the northern Great Lakes, they wouldn't have installed it if their house had access to natural gas.
Our house came with one and we upgraded the unit a few years ago. It's very efficient in terms of units of energy consumed, but in my area of the world gas is significantly cheaper than electricity so it ends up being expensive to run.
That said, we will install solar at some point and then it'll be "free" HVAC.
There's a pretty significant upfront cost in getting them drilled, and many homes need the vertical drilling if they don't have sufficient yard space for a horizontal system. It gets harder if you have your own septic drain field too, as that will complete for yard space.
The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option though.
Nat gas and central AC are way cheaper.
I paid about EUR 4500 for a 114 meter drill hole including installation of brine (ethanol in my case actually) and removal of spoils. My 8kW heat+water pump was about EUR 7000.
I can spec out a gas burner for about EUR 4000 and a central AC for EUR 5000, but I bet the efficiency of the ground source heater would quickly trump the cost of buying gas regularly.
Although if you needed a new septic field, I would think ground source thermal would be significantly deeper than a drain field which is only like a foot or so down so you could stack them.
Air source heat pumps are insanely more efficient and just plain better these days too. It used to be that if the air was below 40F you couldn't heat your house with a heat pump. Now, you can heat your house even when it's -10F
If you can tolerate the price, I am _confident_ that you will pretty much always have better results using the Earth as your thermal exhaust, because you don't have to dig very far to find a large region that's pretty much always at 50 F.
The downvotes are unfair.
The price of things - heat pumps and alternatives - in different regions - even different regions within the US - varies by what people are prepared to pay not what they cost to produce.
The nordics have traditionally had cheap heat pumps whereas piped gas is only in the biggest cities and I’ve never seen bottled gas in the countryside. The competitor used to be cheap electricity and wood. Ground source heat pumps for rural install have been priced to compete with wood.
In the US the market could be shaped by regulation and taxation etc. It’s the choice of the US to have cheap fossil fuels and not embrace tech instead.
> Air source heat pumps are insanely more efficient
Citation needed?
Efficient how? I'm sure a heat pump designed for a narrow range of input temperatures AND working with water which can transport a lot more heat should easily be more efficient.
https://www.energysage.com/heat-pumps/compare-air-source-geo... Seems to disagree
I assuming he means insanely more efficient than they used to be, not more efficient than ground-source (awkward wording though). I suppose they can also be described as more efficient in installation time, cost and equipment than ground source, but clearly not in operating efficiency.
Shallow geothermal works fine for heating. And you can use the ground as a heat sink. But if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells. Fervo Energy claims to have found 270C at 3350 meters well depth. That's progress.
> But if you want to generate power, you need to get down to where temperatures can boil water.
Why is that the case? Can't you go down to where it's like 70-80 deg C and close the gap using heat pumps? Yes, you need to put some energy in, but I would expect that the whole process would still be energy-positive at some temperature that's lower than 100C?
> if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells.
That’s going to be very dependant on location.
Here in NZ there are regions where water is boiling at surface level.
According to the below, 18% of our power is produced with it.
https://www.eeca.govt.nz/insights/energy-in-new-zealand/rene...
"New Zealand has an abundant supply of geothermal energy because we are located on the boundary between two tectonic plates. ... Total geothermal electricity capacity in New Zealand stands at over 900 MW, making us the fifth largest generator of geothermal in the world. It has been estimated that there is sufficient geothermal resource for another 1,000 MW of electricity generation."
That's not all that much. That total would be about equal to the 75th largest nuclear plant in the world.
Good sites where high temperatures are near the surface are rare. California has a few, but no promising locations for more.
> That's not all that much
May not be much in world terms but here in NZ national demand maxes out at around 5.5GW so bringing another GW on stream would be quite handy. Most of the geothermal is a lot closer to Auckland* than our hydro is so so that would be another positive aspect.
* Auckland has 25% of the population so a corresponding amount of energy has to be pushed its way.
Is there any earthquake risk from drilling near tectonic plates?
> That's not all that much.
We don’t have many people. It gets worse’s though, we burn coal and are looking to fund a gas terminal. We have abundant other ways of generating power and subsidise an aluminium smelter for some reason.
Coming up next, data centres.
‘Clean, Green New Zealand.’
You brought the conversation in a circle, since the point of this new technology is the geology you speak of is rare.
There are also places in the US with boiling water at the surface. I live near one of those places so always curious about geothermal. There's a spot near my house in a creek bed where snow always melts even in deep winter so apparently I have some potential heat source. Our well water is cold though.
Not near me, but hot water spring, rivers and beaches made for a nice soak every now and again.
Turning them all into power plants would be a shame, but there is plenty of space for both.
I think this looks interesting, but still very early stage. The “150 GW revolution” sounds more like theoretical potential, not something we will see soon in real deployment.
Main problems: drilling is still expensive, managing induced seismic activity is not trivial, permitting can take long time, and you also need transmission infrastructure. Also not yet proven that companies like Fervo can scale this in reliable and low-cost way.
Nope. To efficiently tap geothermal energy, you need to boil something but not necessarily water. Isopentane, for example, boils at 28º at standard pressure, so they pressurize the secondary loop to raise the boiling point close to whatever the primary loop temperature is.
The idea that geothermal only works well at steam temperatures is outdated 20th-century thinking.
But the energy in boiling isopentane would be less right?
Yes, the efficiency is worse, but as is also the case for solar power you need to get used to not caring much about efficiency. It is nuclear energy where the primary side is provided free of charge. The Carnot efficiency is almost without relevance.
In geothermal there is still a lot of interest in efficiency and exploring different working fluids because binary systems now have efficiencies of 10-20%. That is why you see companies like Sage Geosystems working on developing / deploying supercritical CO2 turbines to try and boost practical power densities.
Framingham, MA has a geothermal system using ground source heat pumps like what you are describing
https://www.smartcitiesdive.com/news/first-networked-geother...
I think you're describing what is known as "district energy" systems.
Whisper Valley in Austin Texas is one example of a neighborhood geothermal installation: https://www.canarymedia.com/articles/geothermal/texas-whispe...
Maybe not quite exactly what you envision.
> Maybe not quite exactly what you envision.
I'm too zonked to pick out the method from the article - but I'll offer that geo methods can be region specific. What I described fits the SE US, with our 13 month summers and abundant underground water.
District heating and chilled water is uneconomical for single-family homes. It does work well in medium to high density areas.
I don't know how economical that is, but just as an anecdote - the town I'm from in Poland has district heating to all single family homes, town of about 20k people. And coincidentally, I now live in the UK and a new estate near me has district heating to all the houses they are building, not apartment blocks. So it must make some sense to someone, or they wouldn't be outfitting 100+ houses this way.
It’s uneconomical in an already built out area or a non central planned economy, and also the US is special case since we have dirt cheap natural gas that is used for heating.
Digging up streets to run distribution lines, running service drops to every existing house, installing a heat exchanger and valves in every house is astronomically expensive given the amount of energy used by a single residence.
If you’re building out a new neighborhood on a greenspace plot, installing the district heating/cooling piping is much cheaper since you’re already laying electric, water, sewer, and mane gas lines.
At least in parts of Eastern Europe (especially the former GDR) district heating systems were introduced as a response to the oil crises of the 70s, resulting price shocks and the transport of coal to households being very labor and resource incentive [1].
[1] https://www.ndr.de/geschichte/schauplaetze/Windkraft-und-Erd...
"I don't know how economical that is"
Sure you do. Think about it. Its just drilling a hole and making electricity from the heat. We have been able to do this for a very long time. So if people aren't really doing it much, its not economical. If it was now becoming economical, the article would describe some new way of doing it that makes it economical. The article doesn't, so you "know" it isn't.
PS This has been tried many time, it only works in very specific situations, usually places where building a full PP doesn't make sense or where you are making a lot of electricity for some other purpose (mining usually).
> Its just drilling a hole and making electricity from the heat
District heating does not involve making electricity.
Sometimes district heating and electricity generation does combine though:
> Wärtsilä’s combined power generation and heat recovery plant offering comprises solutions for combined heat and power (CHP) including dynamic district heating (DDH), district cooling and power (DCAP) and trigeneration for applications that require both heating and cooling.
https://www.wartsila.com/energy/engine-power-plant-solutions...
Not always, but as the sibling noted, there are plenty of combined heat and power plants. They recover as much of the energy as possible from the exhaust gas streams and run pretty efficiently.
The “new” way is plasma drilling.
That's still a science project, they are piloting zapping a small hole to 100m. Very uncertain whether it will amount to anything.
>>Sure you do. Think about it. Its just drilling a hole and making electricity from the heat
...what? What does that have to do with district heating? The one in Poland is coal fired, the one in the UK is electric.
Isn't that similar to how neighborhood heat pumps work?
https://www.araner.com/blog/district-heating-in-sweden-effic...
Heat pumps require a specific temperate differential to work. So they work in zones with are a bit hotter or colder than you would like and so require moderate amounts of heating or cooling. They don't work in temperate zones nor in very hot or cold places. So Santa Fe or Minneapolis for example they work but Mexico City or San Francisco they don't. If you are in a place where they work and that isn't too dense or has earthquakes, go for it. If not, don't. There are businesses that will help you understand when they do and don't make sense. Those businesses don't sell heat pumps though (the businesses that sell things will almost always tell you it works, even when it doesn't, for example PV in the UK doesn't work).
I’ve never heard a claim that heat pumps won’t work well in a climate like San Francisco and, from looking at the annual temperature patterns, it seems like both air source and ground source heat pumps should work extremely well as they do in the “shoulder seasons” here in New England.
> pv in the UK doesn't work
tell that to 6% of UK electric production https://www.bbc.com/news/articles/cz947djd3d3o (up from 5% in 2024
Heat pumps have gotten a lot better, you need a pretty extreme climate for them to start to struggle, even the air-source ones.
(And PV works well enough in the UK for it to be a no-brainer to put on residentials roofs, which is on the whole the most expensive way to deploy it. Though this is in large part due to the way that it competes with retail prices and not wholesale prices)
Wait Minneapolis is definitely very cold for about half the year.
One of the problems with the data center boom is its use of fresh water. How does geo-thermal plants use water and how much?
The water at these temperature / depths has a lot of dissolved salts and minerals so it's not (human / ag) usable. Modern designs are closed loop systems where production wells bringing the hot water to the surface go through a heat exchanger to a different working fluid to drive the turbine and then is re-injected back into the reservoir. There is consumptive water use for fracking the reservoirs in these types of enhanced geothermal systems, but beyond that it's more water redistribution in the area around the well systems where re-injection and production lead to different pressurization from pumping / natural ground water replenishment rates.
> One of the problems with the data center boom is its use of fresh water. How does geo-thermal plants use water and how much?
Baring leaks, ground source heat pump geo will consume no water at all. Water is pumped from one layer of the aquifer and is returned to a slightly higher layer.
I dont know why this keeps coming up? It is a closed loop system. The water aren't used at all.
Many data centers use evaporative cooling.
Oh, Fervo Energy again. They're trying to IPO, hence the hype. Wikipedia's warning: This article reads like a press release or a news article and may be largely based on routine coverage. (February 2026) This article may have been created or edited in return for undisclosed payments, a violation of Wikipedia's terms of use. It may require cleanup to comply with Wikipedia's content policies, particularly neutral point of view.
Here's a more realistic evaluation of Fervo.[1]
[1] https://www.latitudemedia.com/news/what-fervos-approach-says...
That's Wikipedia warning about the quality of the Wikipedia page, not about the company.
This isn’t really an evaluation of the company, just explaining how they had to use different financing approaches as they grew and derisked their technology (which makes sense).
Compared to some other new approaches for getting clean base load power, it seems like they’ve been pretty grounded and methodical.
They're way ahead of the microwave drilling people.
There's no reason why this shouldn't work. But they've been at it for 9 years, with considerable funding, and it doesn't really work yet. That's a concern.
> There's no reason why this shouldn't work. But they've been at it for 9 years, with considerable funding, and it doesn't really work yet. That's a concern.
It does work. They've had a pilot project producing 3 megawatts since 2023. But scaling takes a lot of time and money, particularly when it's something new and you have to go through a lot of operational learning.
Shale took something like 30 years to become a thing. 9 years is nothing in the energy space.
It does work technically I think it is still an open question if it can work economically. There are issues of commercially viable flow rates / thermal decline rates that are harder physical limits you run up against and the pilot design doesn't address. In human timescale terms it's more like heat mining rather than renewable heat due to thermal depletion rate vs replenishment rate. These systems have a targeted lifetime of ~20-30 years and net power will decline over this timespan.
"There's no reason why this shouldn't work."
Geothermal has had the same problem for its entire history. That problem is that the water being heated goes through the ground (not in a pipe) to "gather" more energy. But this means that when the water comes back up, it has a lot of weird salts in it (and other things). Those salts cause corrosion, lots and lots of corrosion, far more than even a maritime environment. So the plant needs to be shutdown a lot of the time for repairs. And that's what makes it uneconomical. Also, the salts often contain things that require special handling which also increases costs.
PS This is why geothermal works in Iceland where there is so much geothermal heat they can use pipes. In CA, they can't so it doesn't work there.
Fervo uses engineered reservoirs in granitic basement rock so this is less of an issue. Hot rock in a working fluid can still dissolve silicates out of the granite and lead to scaling / degradation of the flow rates through the reservoir and that is a risk but chemical anti scaling treatments are used to reduce this.
CA has the worlds largest geothermal power complex in the Geysers. That one field produces an equivalent amount of power as all the geothermal in Iceland and there are others.
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.
There isn't one. They are trying to politically pressure a utility to build some geothermal plant. But utilities have engineers who will tell their bosses that this plan doesn't work. So the companies selling the geothermal plant are trying to politically pressure the utility to do yet another thing that they know won't work. PG&E for example has several geothermal plants which have been economic disasters and were and are being shutdown.
The core breakthroughs were working with partners to develop PDC bits that enable high rates of penetration in drilling out these horizontal wells in high temp granitic rock and then demonstrating plug / perf fracture networks that have a high engineered permeability in these source rocks to support economical flow rates and heat transfer. These were considerable advances over previous efforts.
There will be other learning by doing advances in how you structure your power plant design to take advantage of these to make practical long term power production possible (well spacing and injection / production placement / flow rate and temperature decline management).
> PG&E for example has several geothermal plants which have been economic disasters and were and are being shutdown.
Those are very different from EGS
4th paragraph of TFA:
> Several companies are now building upon existing techniques for accessing geothermal resources by integrating enhanced geothermal systems (EGS) into operations. While conventional geothermal systems produce energy using hot water or steam, pumped from naturally occurring hydrothermal reservoirs trapped in rock formations underground, EGS use innovative drilling technologies, such as those used in fracking operations, to drill horizontally and create hydrothermal reservoirs where they don’t currently exist.
Sounds like marketing hype to me.
Geothermal reservoirs exist at depth.
Drilling horizontally doesn’t magically reduce the depth, nor the problem that drilling in to hot rock is like drilling in to plasticine, at least for temperatures worth working with.
In traditional fault hosted (not magmatic) geothermal the convection of the water up the fault brings the thermal energy closer to the surface where drilling depths are economical. This convection heats the surrounding rock and over hundred thousand - million of years brings the background temperature around a large volume at depth surrounding these systems considerably above traditional background geothermal gradients. By drilling into a much larger volume of impermeable hot rock surrounding a very small permeable fault hosted section you can considerably enhance the power potential of a traditional fault hosted geothermal system (the E in EGS). That is what Fervo is doing and why their projects are situated right next to traditional geothermal power plants.
The assumption is that if you can increase drilling efficiencies enough then you don't even need a fault hosted or similar system to bring that energy close to the surface, you can just drill down deep enough to get at similar temperatures. That is a big assumption in the economics.
EGS has been around for at least 15 years. See AltaRock Energy as an example (I’m sure there are others). They started almost 20 years ago. https://en.wikipedia.org/wiki/AltaRock_Energy
So it basically says nothing useful other than try to generate hype and make them look good.
No. Current geothermal projects need very specific geology to work, its very rare which is why geothermal is such a small blip in the overall energy picture. Enhanced Geothermal Systems (EGS), the technique Fervo is using, can create the conditions to be able to generate electricity. The hope is this will greatly expand the number of projects that can be developed.
Doesn't that sound useful to you?
My understanding is that it's due to better drilling techniques. The industry learned a fair bit from fracking and they're learning more from experience as they apply it to geothermal.
No particular breakthrough, but there's a learning curve and they learn more as they do more. Other industries sometimes work that way, too.
https://www.austinvernon.site/blog/geothermalupdate2026.html
While I’m not extremely bullish on large scale geothermal, much like with Housing, we need any and all types of it.
Those geothermal plants up by Mammoth Lakes are looking like a great idea right now
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.
[1] (2023) https://time.com/6302342/fervo-fracking-technology-geotherma...
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.
Would be great to see this in our lifetime
Is 150GW enough for a “revolution”? That’s about 10% of current total power production.
Solar and wind, with battery storage, can get you to say 90%, and then you only need 10% from other sources like geothermal and nuclear to fully decarbonize.
Solar is at 7%. It's very significant.
There's one of those sites near where I live. The numbers would be amazing if true, but feel a lot like "to good to be true" to me
https://www.opb.org/article/2025/10/06/super-hot-rocks-geoth...
Newberry Volcano is too good to be true in that there are few (outside of Yellowstone) equivalent sources of geothermal awesomeness at similar depths in the USA. Good for research bad for generalization of drilling costs to hit similar temperatures. There are federal protections for geothermal drilling anywhere near Yellowstone.
What is the point of building energy outside of solar farms? I'm sincerely asking
An inexhaustible 24/7 production capable plant has many advantages over solar and maintaining large most types of battery banks.
Cost is like 90-99% of what matters. Last year, China installed 300GW of new renewables and 0GW of geothermal, despite geothermal being "an inexhaustible 24/7 production capable".
Geothermal will compete with solar if they can get the cost low enough. I hope they succeed!
Night time? But batteries! Several cloudy days in a row? More batteries! Cost? -> a mix of sources becomes attractive
https://imgur.com/a/dV8gk3R
can you find curves like this for any other power source?
also batteries are getting exponentially cheap too
These are typically representative of cost performance per watt of one part of a more complex deployed energy system. Things like the aluminum / steal for the container / framing, copper / aluminum for the transmission and wiring, land and labor for installation decline at much less aggressive rates or increase over time.
In almost all pareto optimal least cost energy system models that I've seen, high penetration of solar, wind, batteries plus some minority amount of (clean) baseload power is the most capital efficient energy system.
The whole continent of America made a breakthrough?
There is no continent called “America”.
You know how the United Arab Emirates are known as the Emirates, how the United Mexican Sates are known as Mexico and how the United States of America is known as America? Are you unfamiliar with what synecdoche is?
Yes. North America.
United States–Mexico–Canada Agreement (formerly NAFTA)
https://en.wikipedia.org/wiki/United_States%E2%80%93Mexico%E...
https://www.ghy.com/trade-compliance/guidance-on-us-energy-i...
https://www.heritage.org/trade/report/analysis-the-united-st...
Now USMCA (if you are American) or CUSMA (if you are Canadian) or T-MEC (if you are Mexican).
Canadian United States Mexico Agreement.
It is up for review July 1st I believe.
It expires in 2036
Or, as you've presented, three of the twenty three independent states and territories of North America.