Physics / mechanism
Deep geothermal extracts heat from rock at depth (3–10 km), where temperatures reach 150–300 °C independent of surface climate or volcanic activity. Three approaches dominate: closed-loop (Eavor’s “Eavor-Loop” — sealed multilateral wellbores circulating working fluid, no water extraction, no seismic risk), enhanced geothermal systems / EGS (Fervo — hydraulic fracturing of hot dry rock, creates permeable reservoir, circulates water), and millimeter-wave drilling (Quaise — gyrotron-generated 95 GHz beams vaporize rock, targeting 20 km depths and 500 °C). Key parameters: levelized cost of energy targeting $50–80/MWh at scale, capacity factors >90% (baseload), wellbore diameter and thermal drawdown rate govern economics. Fervo’s Cape Station (320 MWe, Utah) is the current EGS benchmark. All three require breakthroughs in drilling cost per meter.
Competitive landscape
Competing baseload-clean options: nuclear (fission SMRs, Radiant, Kairos) and long-duration storage (iron-air, gravity, compressed air) paired with variable renewables. Adjacent drilling tech includes horizontal directional drilling from O&G and plasma/laser perforation R&D. Quaise’s millimeter-wave approach overlaps with fusion heating technology (gyrotrons from ITER supply chain).
Companies using
Connected ideas
Sources
Frontier (open questions)
See frontier: in frontmatter. Investment framing in Next Gen Geothermal; sits under Baseload Power.