I am a big fan of this closed loop system from a technology standpoint, but I am not a fan of assuming your audience is stupid and spreading propaganda. I’m a little disappointed that the oil and gas dig on the critical minerals requirements of renewable energy passed in the edit unchallenged. Pure O&G talking points and propaganda, and I’m going to hang a lampshade on it so we can all see what is happening here and consider the information presented accordingly.
First, the most obvious FUD talking point tossed out casually and needlessly by Mark. He just couldn’t resist throwing a shoulder at Solar and Wind for no reason at all, and misleading or confusing everyone because he’s clearly not playing by the same rules when he does his own lifecycle analysis of their closed loop system. Because Eavor still relies on a generator they are in the same boat as Wind in terms of critical minerals for getting electrons from thermal energy (heated water or moving air – both a fluid driven by thermal gradients). Solar is a bit different, but that payback period is 1-4 years for solar vs. 1.5 years for wind. Construction for Eavor is a lot more technical than it is for Wind and Solar, their lifecycle critical materials probably look about the same as Wind per MW but might turn out to be a lot more intensive due to their smaller scale, less repeatable, plant manufacturing process. It is all trivial in terms of consumption for fossil fuels, which need all the infrastructure plus a steady supply of new fuels that also have to be extracted. Mark is showing his 4-months removed status right now, this talking point wasn't aligned his Eavor's mission or interests in my opinion.
Mark’s really throwing shade at the battery build outs, but the thing about batteries is that they are not a power source, they are a power buffer. Wind, Solar, and Geothermal are all sources (with some systems able to perform some kinds of storage: chimneys for wind, photovoltaics from thermal emissions, pumped geothermal). Batteries make Geothermal better just like they make Wind and Solar better able to serve the real, variable, and messy demands of customers. He’s taking a shot at himself here; maybe he’s hoping just beating those other guys in green energy is enough.
If we want to get petty, we can also calculate the volume and mass removed from those holes in the ground at the Geretsried facility: 472 tons of materials (under Germany, mostly Sandstone and Limestone; 65.6 miles of 6.125" bore-hole across 2 vertical 2.8 mile holes and 6 pairs of 10-mile loops) just to make the holes to put the system in the ground. Are we going to have <i>a big conversation</i> about all the material extraction required, or recognize that the electronics required for the Wind and Geothermal capacity of Gertsried (as all electricity – being super generous to the Eavor system dealing in low-grade heat) are both going to be about 5 tons for 75MW capacity and Solar at that capacity might be 20 tons – and that most of the impacts of any power plant siting is going to be dominated by mass disruption at that location (and any fuel requirements over the lifetime). This was a dirty throw-away line of Oil and Gas propaganda from the long-time gas-man and it went by without comment.
The other, came earlier and I missed its significance unit Mark threw up that red flag of not participating in good faith.
When Jeanine said A “garden hose leaking” she was not talking about “a leak from a garden hose;” 2 cubic meters is 70 cubic feet is 523.6 gallons per day, weighing 4,345.9lbs. This was trivialized as no big deal, but that’s a game with units and familiarity (and the intentional misrepresentation that the leak was that of a leaky garden hose, not a tap running a garden hose all day). If you need to schedule a 15-ton water truck every week to deliver additional fresh water for the 100-year lifecycle of this installed loop… yeah, this is how we get salt-brine upwelling and blown out wells in the Permian Basin. It is only no big deal when you are externalizing these costs, which was counter to the whole point of building and installing a closed system (ok, being able to leverage the siphon effect is why closed loop is economic, but non-pollution of the environment is a co-benefit that is discarded here – also leaks tend to go both directions over 100-year timescales so you are going to foul your system 'unexpectedly' in regular service). Anyway, the no big deal assertion only fits when you are ignoring the impacts you aren’t being held accountable to. That’s a traditional Oil and Gas approach to power generation, I suppose, but it isn’t what we need more of in the world.
I do love this technology and think systems like this are the sane way forward for harnessing geothermal power everywhere. I just wish the industry wasn’t so obviously skeevy.
Yeah. It (dissing extraction for solar/wind/batteries) is part of the playbook for SMRs and geo and CCS which has been resuscitated as a potential "clean/firm" source for CO.
The German plant cost $34/kWe, $4+/kWth. EU targets for geo are around $2/Wth. So we'll see. Even if the speed of drilling increases there are miles of "insulated" metal pipes, fancy grout, etc., for this AGS. For EGS, there are phenomenal quantities of frack sand.
An annoying thing right now is the instant switch from 50% ITC for wind and solar (if inc. American made and in "justice" zones) to basically 50% for nukes and geo. But it's still not clear how many can actually be located. None of it is "anywhere." Geology, cooling water, HV transmission, gas pipelines, CO2 pipelines, NIMBYs...
In CO, some local ranchers and and resorters bought up offered geo leases when they realized how "industrial" the facilities might be.
2 m3/day is less than the average daily water use of 2 households in the US. That’s not going to break the water bank.
Direct drive wind turbines use a suite of rare earths/critical minerals not required for conventional generation using the heat sourced in the Eavor process. Disposal/recycling of obsolete wind turbines and solar panels is, at best, in a nascent phase in N.A.. Recycling of lithium batteries is further along but we are far from a closed loop system, which should be the goal.
Social barriers to decarbonization are a far bigger obstacle, in the US especially, than the technical barriers. The Eavor people missed a chance to make the point that geothermal is a good social fit. Geothermal drilling requires the highly developed set of skills now used mostly for oil and gas production. Geothermal provides an easy crossover employment alternative as the oil/gas industry inevitably winds down in the US and Canada (the energy return on energy invested developing hydrocarbons is falling especially in shale oil).
Eavor’s geothermal can be load following and thus a good complement to solar/wind.
I am very uncomfortable with the oh-so-casual lumping of natural gas/methane in with discussion of truly clean renewables like wind and solar. This is subtle propaganda and needs to be challenged because gas is just as dirty as coal.
I think that geothermal power could compete with solar and wind power with battery storage, but the LCOE is $65/MWh and $76/MWh dispatchable for solar and batteries (Ember 12/2025). This is pretty cheap. It is usually the market competitiveness that determines If something will scale, like the extraordinary scaling and inexpensiveness of solar, wind and batteries.
DAVE, Seems like a natural for for the old, deep copper mines like Quincy. in Hancock in the Michigan Upper Peninsula. The Quincy (60 degree mine shaft )is over a mile deep, and could be extended along with the horizontal loop or just use the old stopes as reservoirs. Quincy closed after WW2, because the working conditions became untenable for human contact if dug deeper. This is just one of many Mines in the UP "Copper Country" like Houghton, Hancock, Laurium, Calumet other were linked together. I I earned my BSME from. Michigan Tech within had been called Michigan School of Mining and Technology. I hung with the Civil Engineers and had great fun desending some of the older 45 degree mines like Mohawk. I would suggest contact DRJoshua Pierce who recently taught at Tech and has written a number of scholarly papers (all open source) on Solar cells, , solar panel design and all things clean energy. He now at Western University in London, Ontario Canada.
Aha! Heat for Euro district loops or whatever at 190F or less, and 100% heat transfer, makes a lot more sense than trying to get 400F heat/water to make electricity at 15% net efficiency.
Also the Euros are willing to pay, what $20/MMBtu for clean heat into the district loop, as opposed to USA where most large users can get $4/MMBtu gas. And where we still have district loops they are old steam things that require the equivalent of maybe 300F.
The Eavor system may still be kinda capital intensive for the Euros. Very dependent on depth and temps and water saturation/flow around these pipes.
The Euros have been building geo heat for a hundred plus years using "doublets" into already permeable formations. That is, separate injection and production wells using natural ground water at 150 to 250F I think in limestone layers usually. Recently using cooler formations and boosting the temps with water-water heat pumps up to district loop temps.
Let a thousand flowers bloom or however that goes.
On the subject of limitations of heat production and decline over time in geothermal applications:
-since the value of wholesale electricity cycles reliably on a daily basis, why don't I hear about geothermal electricity production being economically optimized in a demand response sense? For example, by producing peak electricity in the evening when demand is highest. Can geothermal electricity production be easily ramped up and down?
A heat reservoir can be charged with excess energy and discharged faster than a natural recharge rate to burst capacity, but you are still limited by the on-site generator, your pumps, and interconnect. If you've interconnected for peak capacity you've over-specc'd for day to day, same for every other part. The nature of the heat exchange here doesn't lend itself to peaker behavior.
Some district heating uses vertical bores and a 6-month diffusion length in the soil to store heat in the summer and exchange in the winter - this isn't a grid response story.
One of the advantages of a closed loop system is the siphon effect which means they aren't a pump-heavy system (runs on its own, but runs at a natural rate). They'll struggle with ramping or over-producing to line up with demand variation. Much better to leave a grid storage solution as a buffer to recharge and discharge with the steady state production from the steady baseline system. And of course this makes the throw-away jab at Wind and Solar so unnecessary in the interview.
Thanks for this EAVOR update! EAVOR is the only remaining active industry participant in the Sonoma Clean Power (SCP) Geothermal Opportunity Zone project that's intended to eliminate all remaining fossil fuel generation in the SCP portfolio within, hopefully, 5 years. Chevron dropped out, but they've already purchased a 4.5 square mile ranch property in the valley below the Geysers Geothermal Field located on the Sonoma - Lake County border. One wonders if they might be courting an AI developer. Existing steam wells at the Geysers average around 8,500 feet deep, with some reaching as deep as 12,900 feet.
I am a big fan of this closed loop system from a technology standpoint, but I am not a fan of assuming your audience is stupid and spreading propaganda. I’m a little disappointed that the oil and gas dig on the critical minerals requirements of renewable energy passed in the edit unchallenged. Pure O&G talking points and propaganda, and I’m going to hang a lampshade on it so we can all see what is happening here and consider the information presented accordingly.
First, the most obvious FUD talking point tossed out casually and needlessly by Mark. He just couldn’t resist throwing a shoulder at Solar and Wind for no reason at all, and misleading or confusing everyone because he’s clearly not playing by the same rules when he does his own lifecycle analysis of their closed loop system. Because Eavor still relies on a generator they are in the same boat as Wind in terms of critical minerals for getting electrons from thermal energy (heated water or moving air – both a fluid driven by thermal gradients). Solar is a bit different, but that payback period is 1-4 years for solar vs. 1.5 years for wind. Construction for Eavor is a lot more technical than it is for Wind and Solar, their lifecycle critical materials probably look about the same as Wind per MW but might turn out to be a lot more intensive due to their smaller scale, less repeatable, plant manufacturing process. It is all trivial in terms of consumption for fossil fuels, which need all the infrastructure plus a steady supply of new fuels that also have to be extracted. Mark is showing his 4-months removed status right now, this talking point wasn't aligned his Eavor's mission or interests in my opinion.
Mark’s really throwing shade at the battery build outs, but the thing about batteries is that they are not a power source, they are a power buffer. Wind, Solar, and Geothermal are all sources (with some systems able to perform some kinds of storage: chimneys for wind, photovoltaics from thermal emissions, pumped geothermal). Batteries make Geothermal better just like they make Wind and Solar better able to serve the real, variable, and messy demands of customers. He’s taking a shot at himself here; maybe he’s hoping just beating those other guys in green energy is enough.
If we want to get petty, we can also calculate the volume and mass removed from those holes in the ground at the Geretsried facility: 472 tons of materials (under Germany, mostly Sandstone and Limestone; 65.6 miles of 6.125" bore-hole across 2 vertical 2.8 mile holes and 6 pairs of 10-mile loops) just to make the holes to put the system in the ground. Are we going to have <i>a big conversation</i> about all the material extraction required, or recognize that the electronics required for the Wind and Geothermal capacity of Gertsried (as all electricity – being super generous to the Eavor system dealing in low-grade heat) are both going to be about 5 tons for 75MW capacity and Solar at that capacity might be 20 tons – and that most of the impacts of any power plant siting is going to be dominated by mass disruption at that location (and any fuel requirements over the lifetime). This was a dirty throw-away line of Oil and Gas propaganda from the long-time gas-man and it went by without comment.
The other, came earlier and I missed its significance unit Mark threw up that red flag of not participating in good faith.
When Jeanine said A “garden hose leaking” she was not talking about “a leak from a garden hose;” 2 cubic meters is 70 cubic feet is 523.6 gallons per day, weighing 4,345.9lbs. This was trivialized as no big deal, but that’s a game with units and familiarity (and the intentional misrepresentation that the leak was that of a leaky garden hose, not a tap running a garden hose all day). If you need to schedule a 15-ton water truck every week to deliver additional fresh water for the 100-year lifecycle of this installed loop… yeah, this is how we get salt-brine upwelling and blown out wells in the Permian Basin. It is only no big deal when you are externalizing these costs, which was counter to the whole point of building and installing a closed system (ok, being able to leverage the siphon effect is why closed loop is economic, but non-pollution of the environment is a co-benefit that is discarded here – also leaks tend to go both directions over 100-year timescales so you are going to foul your system 'unexpectedly' in regular service). Anyway, the no big deal assertion only fits when you are ignoring the impacts you aren’t being held accountable to. That’s a traditional Oil and Gas approach to power generation, I suppose, but it isn’t what we need more of in the world.
I do love this technology and think systems like this are the sane way forward for harnessing geothermal power everywhere. I just wish the industry wasn’t so obviously skeevy.
Yeah. It (dissing extraction for solar/wind/batteries) is part of the playbook for SMRs and geo and CCS which has been resuscitated as a potential "clean/firm" source for CO.
The German plant cost $34/kWe, $4+/kWth. EU targets for geo are around $2/Wth. So we'll see. Even if the speed of drilling increases there are miles of "insulated" metal pipes, fancy grout, etc., for this AGS. For EGS, there are phenomenal quantities of frack sand.
An annoying thing right now is the instant switch from 50% ITC for wind and solar (if inc. American made and in "justice" zones) to basically 50% for nukes and geo. But it's still not clear how many can actually be located. None of it is "anywhere." Geology, cooling water, HV transmission, gas pipelines, CO2 pipelines, NIMBYs...
In CO, some local ranchers and and resorters bought up offered geo leases when they realized how "industrial" the facilities might be.
2 m3/day is less than the average daily water use of 2 households in the US. That’s not going to break the water bank.
Direct drive wind turbines use a suite of rare earths/critical minerals not required for conventional generation using the heat sourced in the Eavor process. Disposal/recycling of obsolete wind turbines and solar panels is, at best, in a nascent phase in N.A.. Recycling of lithium batteries is further along but we are far from a closed loop system, which should be the goal.
Fans should read this analysis by Michael Barnard for a more sobering view.
https://cleantechnica.com/2026/01/15/when-next-generation-geothermal-meets-first-of-a-kind-reality/
...they might have admitted to David that the 8.2MW they intended to deliver worked out to 0.5MW when the rubber hit the road.
Social barriers to decarbonization are a far bigger obstacle, in the US especially, than the technical barriers. The Eavor people missed a chance to make the point that geothermal is a good social fit. Geothermal drilling requires the highly developed set of skills now used mostly for oil and gas production. Geothermal provides an easy crossover employment alternative as the oil/gas industry inevitably winds down in the US and Canada (the energy return on energy invested developing hydrocarbons is falling especially in shale oil).
Eavor’s geothermal can be load following and thus a good complement to solar/wind.
I am very uncomfortable with the oh-so-casual lumping of natural gas/methane in with discussion of truly clean renewables like wind and solar. This is subtle propaganda and needs to be challenged because gas is just as dirty as coal.
I think that geothermal power could compete with solar and wind power with battery storage, but the LCOE is $65/MWh and $76/MWh dispatchable for solar and batteries (Ember 12/2025). This is pretty cheap. It is usually the market competitiveness that determines If something will scale, like the extraordinary scaling and inexpensiveness of solar, wind and batteries.
DAVE, Seems like a natural for for the old, deep copper mines like Quincy. in Hancock in the Michigan Upper Peninsula. The Quincy (60 degree mine shaft )is over a mile deep, and could be extended along with the horizontal loop or just use the old stopes as reservoirs. Quincy closed after WW2, because the working conditions became untenable for human contact if dug deeper. This is just one of many Mines in the UP "Copper Country" like Houghton, Hancock, Laurium, Calumet other were linked together. I I earned my BSME from. Michigan Tech within had been called Michigan School of Mining and Technology. I hung with the Civil Engineers and had great fun desending some of the older 45 degree mines like Mohawk. I would suggest contact DRJoshua Pierce who recently taught at Tech and has written a number of scholarly papers (all open source) on Solar cells, , solar panel design and all things clean energy. He now at Western University in London, Ontario Canada.
Aha! Heat for Euro district loops or whatever at 190F or less, and 100% heat transfer, makes a lot more sense than trying to get 400F heat/water to make electricity at 15% net efficiency.
Also the Euros are willing to pay, what $20/MMBtu for clean heat into the district loop, as opposed to USA where most large users can get $4/MMBtu gas. And where we still have district loops they are old steam things that require the equivalent of maybe 300F.
The Eavor system may still be kinda capital intensive for the Euros. Very dependent on depth and temps and water saturation/flow around these pipes.
The Euros have been building geo heat for a hundred plus years using "doublets" into already permeable formations. That is, separate injection and production wells using natural ground water at 150 to 250F I think in limestone layers usually. Recently using cooler formations and boosting the temps with water-water heat pumps up to district loop temps.
Let a thousand flowers bloom or however that goes.
On the subject of limitations of heat production and decline over time in geothermal applications:
-since the value of wholesale electricity cycles reliably on a daily basis, why don't I hear about geothermal electricity production being economically optimized in a demand response sense? For example, by producing peak electricity in the evening when demand is highest. Can geothermal electricity production be easily ramped up and down?
A heat reservoir can be charged with excess energy and discharged faster than a natural recharge rate to burst capacity, but you are still limited by the on-site generator, your pumps, and interconnect. If you've interconnected for peak capacity you've over-specc'd for day to day, same for every other part. The nature of the heat exchange here doesn't lend itself to peaker behavior.
Some district heating uses vertical bores and a 6-month diffusion length in the soil to store heat in the summer and exchange in the winter - this isn't a grid response story.
One of the advantages of a closed loop system is the siphon effect which means they aren't a pump-heavy system (runs on its own, but runs at a natural rate). They'll struggle with ramping or over-producing to line up with demand variation. Much better to leave a grid storage solution as a buffer to recharge and discharge with the steady state production from the steady baseline system. And of course this makes the throw-away jab at Wind and Solar so unnecessary in the interview.
Thanks for this EAVOR update! EAVOR is the only remaining active industry participant in the Sonoma Clean Power (SCP) Geothermal Opportunity Zone project that's intended to eliminate all remaining fossil fuel generation in the SCP portfolio within, hopefully, 5 years. Chevron dropped out, but they've already purchased a 4.5 square mile ranch property in the valley below the Geysers Geothermal Field located on the Sonoma - Lake County border. One wonders if they might be courting an AI developer. Existing steam wells at the Geysers average around 8,500 feet deep, with some reaching as deep as 12,900 feet.
Thanks so much! Great to have such positive news, especially in these times.
Dave, is there a way to display ALL previous Volts podcasts when I'm in Substack? I can't find a comprehensive list. Thanks!