Geothermal power is a climate moon shot beneath our feet

Original Article ↗ Hacker News Discussion ↗

Media & PR Around Geothermal Startups

  • Several commenters suspect a coordinated PR push by Quaise: New Yorker piece, Real Engineering video, and other YouTube content all appeared within days, with no explicit disclosure of sponsorship.
  • Others note this is standard PR: publicists pitch coordinated embargoed stories to journalists and influencers; much “tech news” is seeded this way.
  • There is disagreement over YouTube explainer channels: some see them as unskeptical, borderline advertorial; others say the engineering content is still educational as long as viewers apply basic media literacy.

Shallow vs Deep Geothermal

  • Thread distinguishes:
    • Shallow “geothermal”/ground‑source heat pumps (tens–hundreds of meters) mainly for space heating/cooling.
    • Conventional geothermal power (hot springs/volcanic zones, e.g. Iceland, California).
    • Deep/“enhanced” geothermal (EGS) using fracking-style methods and horizontal drilling to create artificial reservoirs kilometers down.
  • Shallow systems are widely seen as mature and effective for heating, but drilling cost is high per building.
  • Multiple examples show deep projects failing on economics or geology (Australia “hot rocks”, Finland Otaniemi 6 km wells with insufficient permeability).

Economics and Cost per Watt

  • A recurring theme: no one has yet demonstrated broadly profitable deep geothermal power outside exceptional geology.
  • Capital costs are dominated by drilling; proposed breakthroughs (plasma/maser/microwave drilling) are still early lab tech.
  • Even if heat at depth becomes cheap, several commenters argue the bottleneck is the cost of converting heat to electricity; low- to medium‑temperature cycles (ORC/binary) have ~10% efficiency.
  • Comparisons to other sources:
    • Utility‑scale solar and wind are currently cheaper and faster to deploy in many places.
    • Enhanced geothermal may end up similar to nuclear in capex-heavy economics, but with more room for learning‑curve cost reductions via drilling tech.
    • Residential anecdote: ground‑source heat pump + solar vs air‑source + solar came out similar over lifetime, but ground‑source had much higher upfront cost.

Environmental & Geophysical Impacts

  • Concern is raised about “cooling the Earth” or triggering tectonic changes; others respond with orders‑of‑magnitude arguments: Earth’s stored thermal energy and ongoing heat generation far exceed plausible human extraction.
  • Local resource depletion is real: some long‑running fields cool and must be rested or drilled around; geothermal is “mining heat” on human timescales.
  • EGS and injection wells can induce small earthquakes; choice of geology matters.
  • Conventional geothermal can emit CO₂ and toxic gases (e.g. mercury, boron in Tuscany), though lifecycle CO₂ is vastly lower than fossil fuels; reinjection and closed‑loop designs can reduce emissions.

Heat Pumps vs Geothermal Power

  • There is sustained confusion over terminology: in many markets “geothermal” is used for ground‑source heat pumps that mostly leverage stored solar heat and soil thermal mass, not deep Earth heat.
  • Several commenters argue this should be clearly separated from grid‑scale geothermal power in public discourse.
  • Ground‑source systems are praised where common (Finland, Switzerland, Netherlands district heating), but criticized as uneconomic one‑off retrofits in some U.S. cases.

Intermittency, Storage, and Nuclear Debate

  • Some participants argue solar/wind cannot provide reliable power without massive backup (today usually gas), citing “dunkelflaute” periods in Northern Europe and market issues when wind collapses prices.
  • Others counter that intermittency is an engineering and market‑design problem: build overcapacity, transmission, and storage (batteries, pumped hydro, thermal storage), and use better pricing/hedging mechanisms.
  • There is a heated nuclear vs geothermal vs renewables subthread:
    • Pro‑nuclear voices emphasize reliability and CO₂‑free baseload.
    • Critics cite recent nuclear cost overruns and long build times, arguing that dollars spent on renewables and storage deliver faster CO₂ reductions.
    • Some see geothermal as a more scalable “tech curve” opportunity than large new fission plants, but acknowledge it has “very little to show” at scale so far.

Open Questions and Skepticism

  • Key unresolved technical questions from commenters:
    • Long‑term thermal recharge and lifetime of EGS reservoirs.
    • True cost per kWh once drilling and surface plant losses are fully accounted for.
    • Whether deep enhanced geothermal can be viable in “non‑special” locations, or will remain geographically niche.
  • Overall tone: cautious optimism about geothermal’s potential, but strong skepticism that it is a near‑term “moonshot” comparable to solar/wind without major, still‑unproven advances in drilling and thermodynamic cost.