Jun 27, 2024 · 36m · catalyst
Going deep on next-gen geothermal
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gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
Host Shail Khan interviews Stanford professor Dr. Roland Horne to explore next-generation geothermal energy, examining how oil and gas drilling innovations, Enhanced Geothermal Systems (EGS), and novel architectures are overcoming historical geologic and economic barriers to scale clean, firm baseload power.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. Shayle holds 26.7% of the talking time here. How this is scored →
Shayle as informed peer 4.6 Guest teaching 3.4 Guest disagreement 0.7 Shayle pushing back 0.9
speaking balance: gold is Shayle, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 12:37 Clarification on EGS origins
Guest directly contradicts host's claim that EGS stems from oil and gas fracking, pointing out EGS was pioneered in the 1970s prior to the shale boom.
Hardest push from Shayle ▶ 12:47 Host insists on oil and gas transferHost immediately presses back after the guest's correction, reaffirming that modern EGS applications heavily leverage contemporary fracking techniques.
Biggest teaching moment ▶ 25:51 Supercritical thermodynamics reframingGuest thoroughly reframes host's premise that super deep geothermal is meant for universal geographic access, explaining it is actually about thermodynamic efficiency in existing hot spots.
Shayle holds their own ▶ 10:14 Comprehensive next-gen geothermal taxonomyHost demonstrates deep domain fluency by systematically laying out the technological risk spectrum across EGS, closed-loop, and supercritical geothermal systems.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | Shayle as informed peer | Guest teaching | Guest disagreement | Shayle pushing back | Why |
|---|---|---|---|---|---|---|
| Host Welcome, Swag Announcement, and Geothermal Context | 5 | 0 | 0 | 0 | Host establishes the episode's analytical framing independently, outlining both the geologic and economic historical bottlenecks of conventional geothermal energy before introducing the guest. | |
| Technical Principles of Conventional Geothermal Energy | 4 | 2 | 0 | 0 | Collaborative foundational segment where the host prompts with clear technical categories and the guest explains heat, water, and permeability mechanics alongside binary turbine technology. | |
| Economic Barriers and Subsurface Financial Uncertainty | 5 | 5 | 3 | 4 | Guest corrects host's assumption that EGS originated from oil and gas fracking, noting EGS came first in the 1970s. Host immediately pushes back to defend the relevance of modern oil and gas transfer. | |
| Sponsor Break: Mid-Roll Advertisements | 4 | 4 | 0 | 0 | Following mid-roll advertisements, host asks focused operational questions about EGS deployment, leading to guest sharing Stanford findings on US geographical potential. | |
| Evaluating Closed-Loop Geothermal Systems | 5 | 4 | 0 | 0 | Host frames closed-loop concepts clearly; guest educates on the fundamental physics constraint of thermal conduction versus convective fracture sweep. | |
| Super Deep and Supercritical Geothermal Opportunities and Challenges | 5 | 6 | 2 | 2 | Guest reframes host's conception of super deep geothermal from 'geothermal anywhere' to high-enthalpy thermodynamic efficiency in already-advantageous geologies. | |
| Drilling Innovations: Batch Drilling and Polycrystalline Diamond Bits | 4 | 3 | 0 | 0 | Host invites overview of drilling advances, and guest details how batch drilling and polycrystalline diamond bits significantly compress project timelines and development costs. |
Statements from this episode (15)
Kann: Nearly all US geothermal capacity is in Nevada or California
“Basically all of the geothermal that we've built in the United States is in Nevada or California.”
Horne: Geothermal generates 6% of California's, 10% of Nevada's, and 50% of Kenya's electricity
“Six percent of our electricity comes from geothermal. 10% of electricity in Nevada comes from geothermal, conventional geothermal. And there are countries in the world, ah, Kenya notably takes 50% of its national electricity from geothermal.”
Horne: Rock permeability is the primary bottleneck for conventional geothermal energy
“And so, the three things that you need for your thermal resource are heat, water, and permeability. So, it's hot everywhere to, if you can drill deep enough and almost the entire planet is saturated with water, you know, at depth. But the places that don't hav…”
Horne: Binary geothermal plants release virtually zero atmospheric emissions
“Because the water never leaves, the geothermal water never leaves the heat exchanger, there's basically no emissions at all from the subsurface out into the atmosphere of the environment. The water stays in the pipe, goes back in the ground. It never sees the …”
Horne: Geological uncertainty is the primary cost driver for geothermal
“The biggest cost driver for geothermal development is uncertainty. And because it's a resource, a geological resource, the fact that you don't know exactly how big it is and how long it's going to last, that translates into uncertainty in the sizing of the pla…”
Horne: Next-gen geothermal concepts have existed for 40 to 50 years
“Actually none of these ideas are actually new. Most of them have been around for 40 or 50 years, and several of them tried already. EGS, perhaps, is the one that's been around the longest, first kind of postulated back in the 19 sixties at Los Alamos National …”
Horne: Geothermal fractures brittle volcanic rock, unlike pliable sedimentary rock
“Oil and gas are fracturing sedimentary rocks. Which tend to be more pliable, plastic, and geothermal is fracturing volcanic rocks, which are brittle and hard, and it's a somewhat different process, and it's a somewhat different result as a consequence.”
Horne: Fervo's 90MW Utah EGS project is 20x larger than predecessors
“Their near-term plan is 90 megawatts, which is, you know, probably 20 times bigger than any of the former EGS projects, the old EGS projects that people have done.”
Horne: Conventional geothermal matches average US electricity cost of $80/MWh
“You know, the average cost of electricity in the US is somewhere around 80 dollars a megawatt hour and conventional geothermal is basically at that cost today.”
Horne: Half the US is accessible for $80/MWh geothermal
“So we've estimated that about half of the United States is accessible for EGS at 80 dollars a megawatt hour.”
Horne: Low rock conductivity fundamentally limits closed-loop geothermal heat extraction
“In the case of a drilled hole, the surface area of the hole is quite small, and therefore you depend a lot on conduction of energy, thermal energy through the rock. And rocks actually are not very good thermal conductors. Rocks are kind of insulators actually,…”
Horne: Commercial closed-loop pilot in Germany requires 80 kilometers of drilling
“So the system, they're drawing a closed loop system, sort of the first commercial pilot or whatever in Germany right now, which they're planning. 80 kilometers of holes, if I remember that number correctly, which is feasible but quite expensive.”
Horne: Iceland's supercritical well dissolved its steel casing into black steam
“So I'm reminded of the videos they showed of the supercritical well that they produced in Iceland called IDDP-II. It basically produced black steam, and the reason it produced black steam is that it was producing the steel casing together with the steam. It wa…”
Horne: Batch drilling reduced Fervo's Utah drilling times two- to threefold
“So further again in their EGS project in Utah is doing batch drilling where they're actually drilling, you know, eight wells at a time. Well, not quite eight at a time. They, they're drilling the first segments eight at a time, and then the second segment's ei…”
Horne: Unconventional techniques will cut geothermal drilling costs in half
“Unconventional drilling practice for the normal geothermal industry has actually basically helped or will soon bring geothermal drilling costs down perhaps to half what it was five, 10 years ago, and that really opens up many new areas because, again, you're j…”