12 Comments
Jul 22, 2023Liked by Samuel R

Very encouraging. So much so I was inspired to read the comments (and write my own) for the first time in about a year.

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A division of Chevron, along with Eavor Energy and Cyrq Energy are already under contract with Sonoma Clean Power (SCP), our local California Community Choice Aggregator, to develop 3 new geothermal power projects in Sonoma & Mendocino Counties.

Much of SCP renewable energy is already supplied by The Geysers, a very large local conventional geothermal facility that gets treated wastewater via pipeline from Sonoma County to recharge steam wells. The Cyrq project will repurpose some depleted wells at The Geysers to create a geothermal energy storage system, like a really big storage battery.

Chevron & Eavor will both be constructing new 24/7 base-load closed-loop Advanced Geothermal Systems (AGS) power plants at other TBD local locations. Their purpose is to completely replace all remaining fossil gas generated peak-demand power supplied to SCP.

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This was by far the most exciting energy podcast I have listened to in a helluva long time. What is exceptional is not just the advancement itself but the way you contextualise and tease out the significance of what Fervo are doing.

If you do follow up on this (and I am sure you will), it would be super helpful to explore the international potential of this technology, the kinds of challenges that might crop up in other places - not just geological but regulatory and social. Bear in mind that fracking is enormously unpopular in Europe not only due to its emissions or pollution footprint, but also due to seismicity. If I understand things correctly, Fervo's drilling techniques are very similar to fracking - so are they viable in locations in close proximity to urban conurbations?

Anyway, thank you David for bringing this depth of knowledge on this vitally important topic to a wider audience.

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Interesting. The question I have about this is whether the economically viable geothermal fields line up at all where the needs are greatest.

Globally, the places that will need the most clean firm power are the north-eastern US, Northern Europe, and the colder bits of East Asia (also Russia, but they’re of course unlikely to do anything f under present management).

California will be fine with or without geothermal.

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I'm excited about the possibility of enhanced geothermal but as a health professional I'd like to hear more specifics about the argument that hydraulic fracturing for geothermal is cleaner than for gas. In this episode they addressed possible water contamination from brine, but not from the fracturing process itself. David and Tim imply it's just water fracturing the rock, but my understanding is that a chemical mixture is used to help fracture the rock, and that there are many ways in which hydraulic fracturing and its waste impact water quality. Obviously it's important to view technologies in the alternative context, so one could argue hydraulic fracturing for geothermal is still an improvement even if it impacts water quality, if it decreasing fracking for gas, but still we should know what the health impact is. So... does anyone know the answer to this question? The budding enhanced geothermal industry better get on top of the clean water question because I assume health groups are going to come in baseline skeptical of enhanced geothermal given the use of fracking.

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Joel, my understanding is that gas fracking companies have to put various and sundry additives in their working fluid to prevent it from reacting to hydrocarbons. Fervo targets areas with no hydrocarbons, so it doesn't need that stuff -- its working fluid is basically water with a harmless friction reducer (also used in lots of other industrial & cosmetic applications) added. There's really no water pollution risk here.

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I came here to ask this same question. I noticed you carefully referred to “water” as the substance used, but I didn’t hear Tim say that. I can imagine a world where engineers gain efficiency by adding other substances to the water, in which case the potential groundwater impacts are much less rosy. Would love to hear a follow-on podcast on this topic.

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OK, I'm convinced on the technical feasibility, but I'm not fully convinced on the economics of using these type of powerplants in a high VRE/storage grid as the last resort. I think the high capital costs for these kinds of geo plants will mean they run near baseload, or at least mid-load. But maybe we don't get to a high VRE grid due to seemingly declining enthusiasm for wind and solar.

I looked at the future cost projections in https://atb.nrel.gov/electricity/2023/geothermal. Tim mentioned that these had been made rosier for these "deep-EGS" binary powerplants. I've become a bit pessimistic on rosy "learning curves" for tech that depends on a lot of basically mature inputs like miles of drill pipe and frack sand, both of which have gone up in price, affecting the cost to drill fossil wells too. The former cost is also messing with the "learning curve" for wind. I guess modular binary power plants in the 10s of MW range could become significantly less expensive if their sales increase 100x, but there are still big pumps and condenser fans because the low thermodynamic efficiency requires tossing 85% of the geo heat away to the air, at least if the plants are in the boonies. And those condenser fans can seem pretty noisy in the quiet boonies. I mean wind turbine rotors get dissed for noise, so let's be fair. And wind turbine noise is confined to periods when the wind itself is noisy. And yes, I'll put up with fan or rotor noise for clean power, but someone will say it's disturbing the bunnies.

I hope the power outputs cited are "net" and subtract the parasitic power of fans and pumps. Some schemes floated here in CO seem to depend on using fossil power for those, and then selling the binary geo generator output as clean. (These seem to be looking at lower temp reservoirs, so less efficient generation.) And I'd really, really love to see something here like what he described in Munich, putting this stuff in town, and using all the rejected heat for space heat.

I worry about depletion, but if it really is just 1-2%/year, I'll agree it's better than burning stuff for power, and lower capacity factors would mean slower depletion. And if this is what it takes to get the folks in Utah to use clean power, so be it.

Technically, I admire this. Fervo seems to have been very smart in finding a sweet spot of hot-enough water to be reasonably efficient, w/o trying to drill too deep, expanding the locations where it's feasible. But it's not "almost anywhere" geo to me. The actual electricity/acre doesn't seem that dense to me, but while there is plenty of land in the Mtn West, we just seem to be very sensitive about seeing anything on top of it.

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This was an excellent podcast and sheds a great light on the Oil and Gas Industry technology which can be used to advance a clean energy future. I would be very interested in hearing what advances are being made in Geothermal heating and cooling. Given that a Coefficient of Performance of 5 (Each Watt used for heating or cooling results in 5 Watts of actual Heating or Cooling of a Building) is achievable, it seems to me that the greatest impediment to a wider scale adoption is simply developing an inexpensive method to either create wells for heat transfer to the earth or an improved method of loop exchange which has always been limited by the local energy transfer to the ground through polyethylene tubing. Using Geothermal energy has the potential for as much decarbonization as the transition to Electric vehicles. The concerns over Geothermal Heating and Cooling Installation Costs are dwarfed by a Life Cycle analysis where the equipment cost is off set by its longevity with a 20-25 year life. Unfortunately, few people seem to factor in the Life Cycle Cost and instead view the near future. This might make a great podcast episode.

Thank you for your great work.

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Very cool. Great episode!

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Excellent. Hopeful

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Thanks for this. I read the article after hearing your last podcast on geothermal and wondering if you would cover this.

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