Shift Key Podcast Detailed Summary

Episode: "Say ‘Guten Tag!’ to This New Kind of Geothermal Tech"
Date: December 17, 2025
Hosts: Robinson Meyer (Heatmap News Executive Editor) and Jesse Jenkins (Princeton Professor, Energy Systems)
Guest: Mark Fitzgerald, President & CEO of Eavor Technologies

Episode Overview

This episode explores the recent breakthrough in closed loop geothermal technology, focusing on a first-of-its-kind project launched by Eavor Technologies in Germany. The hosts interview Mark Fitzgerald about the uniqueness of closed loop geothermal systems, the technical and commercial advantages, and implications for the broader energy transition. The conversation dives into the operational specifics of the Bavarian project, the future of geothermal, and what the clean energy world can learn from oil and gas.

Key Discussion Points & Insights

1. Context and Industry Excitement

• The energy transition is challenging, but "there is tremendous innovation going on all over the place." (Jenkins, 02:46)
• Eavor's project in Bavaria is the world’s first closed loop, multilateral geothermal plant. This is a rare 'first-of-its-kind' in modern electricity generation.

2. Understanding Closed Loop Geothermal

• What is it?
  • "We essentially complete a radiator underground. So think of a fork, a fork with maybe 12 tines at the end...we drill a vertical well down, we send out upwards of 12 laterals or 12 tines...and then we do it again. And we connect the end of the fork, two forks together—and in doing so we create a continuous loop." (Mark Fitzgerald, 06:27)
• Key Differences:
  • No need for high-temperature geothermal resources—more regions are viable.
  • No fracking or water injection—environmentally safer.
  • It’s a "closed system"—the same water cycles continually, reducing environmental impact.

3. Technical Innovation & Drilling

• Core innovation is "active magnetic ranging," guiding wells to intersect underground with pinpoint accuracy (11:14).
• Oil and gas drilling expertise directly transfers; no new drilling method is invented, just new applications and cost reductions.
• Efficiency is rapidly improving: "the fourth and fifth laterals were done at 50% of the cost of the first two" (10:12).

4. Bavarian Project Details

• Scale: Each loop is ~16 km underground, world's longest continuous wellbore (13:09).
• Performance: First power generated two weeks before recording; heat and power output as expected or better.
• Capacity: Designed for 8.2 MW power, 64 MW heat (when fully built out) (16:38).
• Current status: Generally cost-competitive on heat in Germany; power generation competitiveness improving with deeper drilling.

5. Market Strategy & European Focus

• Primary commercial focus is Europe's district heating market due to strong policy, high heat prices, and abundant data (18:22).
• Europe chosen for its supportive policy, mature heating market, and even 'average' geothermal gradients.
  • "It was a great opportunity for us to say we're not going to the best place or the easiest place to prove it. We're of the belief that an Eavorloop system can be developed just about anywhere around the world." (Fitzgerald, 22:49)

6. Scale Up and Partnerships

• Eavor plans to focus on innovation and partner with established oil/gas and local operators for rapid expansion (25:09).
• The European district heating market is massive—district heating is a “key pillar to the overall decarbonization strategies” (27:12).
• Skill transfer from oil & gas is seamless; most of Eavor’s staff are ex-oil and gas professionals.

7. Lessons from Oil & Gas

• Oil & gas expertise is essential; almost the entire geothermal skill set is transferred.
• "As fossil fuels continue to...decline in terms of relevance, those skills are transferred right across to geothermal development, whether it's our company or other companies." (Fitzgerald, 29:36)
• Geothermal should be seen as a complement, rather than outright replacement, in the future energy mix.

Notable Quotes & Memorable Moments

• On innovation optimism:
  • "One of the things that keeps me going is meeting and learning from and getting to support and help technology companies that are pushing the frontiers of what we can do..." (Jenkins, 02:54)
• On the core ‘closed loop’ idea:
  • "We essentially complete a radiator underground...we create a continuous loop where water will flow through one vertical well...flow back and then flow up to the surface and generate either heat or power." (Fitzgerald, 06:27)
• On cost reductions:
  • "The fourth and fifth laterals were done at 50% of the cost of the first two." (Fitzgerald, 10:22)
• On environmental sustainability:
  • "Because we don't inject energy, we don't emit, we don't have emissions." (Fitzgerald, 08:35)
• On skill transfer:
  • "The skill sets and the talent transfer almost 100% from oil and gas into geothermal." (Fitzgerald, 28:50)
• On project novelty:
  • "It's not every day that you get to see the start of operations of kind of the world’s first of any new power generation technology." (Jenkins, 14:10)

Timestamps for Key Segments

| Timestamp | Segment | |------------|-----------------------------------------------------------| | 02:24 | Geothermal innovation excitement & host disclosure | | 06:14 | Closed loop geothermal explained by Fitzgerald | | 10:12 | On cost reductions and drilling speeds | | 11:14 | How the 'tines' (well intersections) are connected | | 13:09 | Size and scale of the Bavarian Eavor loop | | 14:26 | Bavaria project backstory and status | | 16:38 | Output numbers (heat/power capacity) | | 18:22 | Why start in Europe? Policy, data, heat market advantages | | 21:17 | Why Bavaria? Geology, existing site, data availability | | 24:53 | Where next? Eavor’s expansion plans and partnerships | | 27:12 | Scale of Europe’s district heating market | | 28:17 | Lessons from oil & gas to geothermal |

Upshift/Downshift Segment Highlights

Jesse Jenkins: Upshift

• Breakthrough in US-based battery companies on silicon anode batteries: higher energy density, faster charging, less dependency on graphite imports (32:17).

Robinson Meyer: (Nuanced) Downshift

• EU likely to roll back 2035 combustion engine ban, but the pragmatic approach includes plug-in hybrids and extended range EVs, similar to successful Chinese strategies (36:56–42:54).

Takeaways for Listeners

• Closed loop geothermal is a major, potentially global decarbonization lever—no emissions, less site restriction, and minimal environmental impact.
• Eavor’s 'radiator underground' design can work in ordinary geology, promising vast scalability.
• Oil & gas expertise is not a liability but a strength for clean energy innovation.
• The European heat market is a proving ground for new technologies.
• Innovation across battery and geothermal sectors continues to outpace policy pessimism, providing real sources of optimism for energy transition.

Closing Notes

This episode is technical yet accessible, revealing both the human side of the clean energy transition and its real-world pace. Both hosts and guest share optimism, technical depth, and strategic perspectives useful for anyone interested in the future of energy systems.