Episode Summary
Executive Summary: This episode argues that conventional geothermal may be vastly larger than official estimates suggest. Zanskar’s founders say modern AI, new drilling tech, and a large exploration data set reveal many more geothermal prospects and much higher per-site productivity than the USGS assumed, potentially making geothermal a major source of firm, carbon-free power.
Main Topics: Why conventional geothermal has been underestimated (Priority: 5/5): The guests contend the USGS relied on sparse, outdated data from an era when geothermal exploration largely stopped after the 1970s-80s, causing resource size and site productivity to be systematically understated. How geothermal resources are found (Priority: 5/5): Geothermal exploration targets hot rock plus permeability. Traditionally, explorers relied on surface clues, fault zones, and trial-and-error drilling; Zanskar uses probabilistic AI models and iterative field testing to improve discovery. AI, legacy data, and model-building (Priority: 5/5): Zanskar combines old geological, geophysical, and drilling records with new data from its own exploration program to build probabilistic models that predict where geothermal systems are likely to exist and how productive they may be. Case studies: Lightning Dock, Pumpernickel, and Big Blind (Priority: 5/5): The episode walks through Zanskar’s discoveries and redevelopments, including a repowered New Mexico field, a Nevada site with a dry first well then a successful second well, and a blind Nevada discovery with no surface signs. Drilling technology and cost reduction (Priority: 4/5): Oil-and-gas drilling advances such as PDC bits, directional drilling, and automated rigs are lowering geothermal drilling time and cost, making exploration and development more efficient. Financing and the development capital facility (Priority: 4/5): Because geothermal exploration is risky, Zanskar created a rotating capital structure to finance exploration portfolios before traditional project finance steps in, potentially de-risking the sector more broadly. Policy, land access, and market demand (Priority: 4/5): Geothermal’s future depends partly on public-land permitting and policy, but demand for firm clean power from utilities and data centers is creating strong market pull.
Key Arguments: Conventional geothermal has been underexplored for decades, so official estimates are likely based on stale, incomplete data and should be revised upward. Heat and permeability are the two essential ingredients; natural permeability is much more valuable than engineered permeability in most cases. AI is useful not as a magic finder, but as a way to combine sparse, messy, heterogeneous data into probabilistic predictions that improve with field feedback. Zanskar’s exploration success across millions of acres suggests both more undiscovered sites and larger-than-expected resources per site. Legacy geothermal fields can be underdeveloped; deeper targeting and improved drilling can unlock much more capacity from existing plants. Natural geothermal resources with strong permeability are cheaper and more attractive than enhanced geothermal resources that must create fractures artificially. A portfolio-based financing model can make geothermal exploration more bankable by diversifying risk across many prospects. Demand from hyperscalers, utilities, and grid operators is making geothermal more commercially relevant because it provides firm, carbon-free, grid-supportive power.
Data Points: U.S. Geological Survey discovered potential (2008): about 9,000 MW - Estimated discovered geothermal potential in the U.S. from the 2008 USGS assessment U.S. Geological Survey undiscovered potential (2008): about 30,000 MW - Estimated additional undiscovered geothermal potential in the 2008 USGS assessment Theoretical U.S. ceiling from USGS estimate: around 6,000–8,000 MW of current U.S. electricity demand - Host’s calculation of how much of U.S. electricity demand that estimate might cover Operating geothermal fields in the U.S.: about 36 - Approximate count of operating geothermal fields discussed on the episode Current U.S. geothermal capacity: roughly 4 GW - Total operating geothermal power in the U.S. mentioned by the host Growth in U.S. geothermal capacity over the last decade: about 1 GW - Approximate increase in geothermal capacity over the prior ten years Zanskar exploration acreage tested: over 5 million acres - Scale of the company’s field testing over the last five years Lightning Dock well depth relative to prior wells: roughly 4x deeper - New production well in New Mexico drilled deeper than earlier wells at the site Lightning Dock thermal output: over 100 MW thermal at the wellhead - Measured thermal energy delivered by the new production well Lightning Dock production record: over 12 months at full capacity - The well has operated without observed temperature decline for more than a year Lightning Dock productivity uplift: 10x to 40x - Company’s estimate of how much more potential the site has than initial industry estimates Big Blind discovery timing: end of 2023 discovery; drilled in 2025; announced in 2026 - Timeline for the blind Nevada discovery Big Blind target depth: around 2,000 to 3,000 feet - Depth at which commercial reservoir conditions were encountered Cost declines from in-house data collection/drilling: 50% to 90% - Reported reductions in some exploration data-collection or drilling costs Portfolio PPA size with NV Energy: 100 MW - Zanskar’s portfolio power purchase agreement with Nevada’s regulated utility Public land share of identified geothermal resources: 90% - Approximate share of identified geothermal resources on public land Deep scientific wells mentioned: 10–11 km in Germany; deeper in Russia - Examples used to discuss deep drilling and unexpected permeability/water
Pivotal Quotes: "The hard part is pairing that model with the field piece of it." — Joel Edwards: Explaining that AI models only matter when they are repeatedly tested and updated with real-world drilling results "We stopped looking." — Carl Hoyland: Answering why conventional geothermal has been stuck for so long "Definitely true today. And we think probably indefinitely into the future." — Joel Edwards: On whether naturally permeable geothermal resources are cheaper than enhanced geothermal sites that create their own permeability
Implications: If Zanskar is right, geothermal could become a much larger, more financeable source of firm clean power than assumed, especially in the U.S. West. Better models, cheaper drilling, and portfolio finance could accelerate commercial scale-up.