America's Geothermal Breakthrough(oilprice.com) |
America's Geothermal Breakthrough(oilprice.com) |
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.
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-...
It seems so smart.
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...
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?
The idea that geothermal only works well at steam temperatures is outdated 20th-century thinking.
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.
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.
https://www.smartcitiesdive.com/news/first-networked-geother...
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.
https://www.araner.com/blog/district-heating-in-sweden-effic...
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.
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.
Here's a more realistic evaluation of Fervo.[1]
[1] https://www.latitudemedia.com/news/what-fervos-approach-says...
Compared to some other new approaches for getting clean base load power, it seems like they’ve been pretty grounded and methodical.
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.
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.
Long Valley Caldera Geothermal Area | Open Energy Information https://share.google/5DvljMhL3EVMDeIAL
[1] (2023) https://time.com/6302342/fervo-fracking-technology-geotherma...
https://www.opb.org/article/2025/10/06/super-hot-rocks-geoth...
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.
Geothermal will compete with solar if they can get the cost low enough. I hope they succeed!
https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_...
Or we could just spin some rocks around.
https://www.torus.co/torus-flywheel
Rather have solar/wind and this than shipping depleting goop from foreign nations.
can you find curves like this for any other power source?
also batteries are getting exponentially cheap too
IT'S HARD TO IMAGINE LESS IDIOTIC WAY OF ENERGY PRODUCTION
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).
Those are very different from EGS
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.
> 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.
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.
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
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 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.
To clarify, our 400' water source is the same aquifer that supplies drinking water to the state.
The water management districts will rubber-stamp permits for these wells. No one else gets off that easy.
The more interesting use of geothermal power, IMO, is pushing heat underground with excess solar while the sun is high and the days are long, and pulling out electricity from heat in the darker times .. done large enough that carries across summer to winter.
Doesn't that sound useful to you?
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.
tell that to 6% of UK electric production https://www.bbc.com/news/articles/cz947djd3d3o (up from 5% in 2024
Solar peaked at 42% of UK electricity generation the other day:
https://www.pv-magazine.com/2026/04/24/uk-solar-generation-h...
(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)
How do you cool the steam off enough to condense so it can go and be boiler feed water again?
Lots of power plants use cooling towers for this which are typically evaporative. Some are dry, sure, but most are wet.
Our method is open on both ends. It draws from one layer of the aquifer and then returns the water to an adjacent layer.
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.
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.
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.
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.
Coming up next, data centres.
‘Clean, Green New Zealand.’
Isn't there a super volcano in the middle of the country? Maybe there are some adjacent hot spots outside of the national park?
Turning them all into power plants would be a shame, but there is plenty of space for both.
You're not required to site them that close either, because of how regional the conditions usually are. A couple miles plus or minus doesn't change things too much.
That said, we will install solar at some point and then it'll be "free" HVAC.
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 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.
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.
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
[1] https://www.ndr.de/geschichte/schauplaetze/Windkraft-und-Erd...
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.
I mean, true. But it was new developments I had in mind for a neighborhood geo install.
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).
District heating does not involve making electricity.
> 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...
...what? What does that have to do with district heating? The one in Poland is coal fired, the one in the UK is electric.
There were a number of steps I had to go through. First I had to file for permission at the County Office, where they verify that drilling in the area is acceptable and that the intended pump follows regulations with respect to cooling media, and that the drilling company was certified to drill for my needs. It did cost about 70 euros.
I needed effective zero plumbing work in the house as it was already prepared to accept heating from a pump like that. Perhaps that is one of the major costs in USA?