Cape Station, future home of an enhanced geothermal power plant, in Utah

Depth, Scale, and Units

• Commenters note Cape Station wells (8,000–15,000 ft) are comparable to some of the deepest geothermal wells (~5 km).
• There’s a long tangent on goofy “Statues of Liberty / Eiffel Towers / football fields / bananas” as units; many find them unhelpful or US-centric, preferring kilometers or miles.
• Some argue people visualize football fields better than abstract measurements; others note international ambiguity of “football.”

Geology and Resource Limits

• Typical geothermal gradient (25–30°C/km) suggests 2.5 km often yields hot water, not superheated steam; people infer this site must have unusually favorable geology.
• Utah sits in a major high-quality geothermal basin with large potential; still, geothermal heat is not strictly “infinite” and can be locally depleted.

Earth’s Heat, Core, and Magnetic Field

• One side claims crustal heat is effectively inexhaustible at human scales; another pushes back on calling it “infinite” and raises speculative concerns about cooling the core and affecting the magnetic field.
• A rough calculation suggests lowering crust temperature by 1 K would require ~10,000 years of today’s total human energy use.
• Others argue the crust is a thin layer over enormous thermal mass; human geothermal extraction is negligible for the core.

Induced Seismicity and Other Risks

• Some note geothermal operations can trigger earthquakes; links are shared for both “risk can be reduced” and “serious problems observed” positions.
• A German town (Staufen) is cited as an example of geothermal drilling causing serious damage.
• There’s disagreement on how big a risk this is, and emphasis that site-specific geology and seismic engineering matter.

How Geothermal Works and Where Heat Comes From

• Heat sources mentioned: radioactive decay of heavy elements, tidal friction from the Moon, and Earth’s insulation by rock.
• Iceland and Swedish home heating are cited as real-world geothermal/ground-heat use cases, but superheated-steam power plants are noted as technologically harder (drill bits melt at high temperatures).

Promise of Enhanced Geothermal Systems (EGS)

• Enthusiasts see EGS (and companies like Fervo, Quaise, Sage, Eavor) as near a breakthrough for clean baseload power, potentially colocated with data centers.
• Deep geothermal is compared to nuclear: high capex and long build times but low operating costs and clean generation; some say if deep geothermal is cheaper, nuclear loses much of its case.
• Others caution about earthquakes, groundwater risks (especially where fracking-derived techniques are reused), and nonzero emissions from some geothermal fields (e.g., mercury, H₂S in Tuscany).

Waste Heat, Emissions, and Water

• There is debate whether geothermal “waste heat” is an environmental concern; most argue CO₂, not waste heat, drives climate change.
• One commenter worries about water vapor as a greenhouse gas; others note the Cape Station design is a closed-loop system that recaptures fluids.
• Water use and cooling are flagged as potential constraints, especially where fresh water is scarce.

Permitting and Comparisons to Other Power Sources

• Some argue EGS could avoid much of the contentious permitting faced by nuclear or fossil plants; others question this, seeing it as more complex than solar but less than coal/gas.
• Nuclear is treated as the closest analog; if deep geothermal can be widely sited, it might cover the “last bit” that solar, wind, storage, and transmission can’t.

Geothermal vs Heat Pumps and “Home Geothermal”

• A long subthread clarifies that:
  • Ground-source heat pumps for buildings are not power plants; they move heat using external electricity.
  • They can deliver more heat than their electrical input (COP > 1), but do not generate net energy.
• Some people loosely call ground-coupled heat pumps “home geothermal,” but others insist that real geothermal power requires high-temperature gradients and deep wells.
• Europe is seen as ahead on neighborhood-scale ground-source heating networks; the US mostly uses such systems for campuses.

Economics, Turbines, and Reuse of Coal Infrastructure

• One shared resource claims turbine costs impose a floor on steam-based generation costs (including geothermal).
• A counterpoint notes there are many existing coal plants with turbines that might be repurposed for cleaner steam sources, though feasibility is unclear.

Technology, Drilling, and Industry Crossover

• Some drilling and measurement companies report their tools are already used on Fervo and Eavor projects, stressing high-temp, high-G drilling tech and horizontal drilling expertise from the oil industry.
• Questions arise about what’s left in the holes (casing, pipes for water) and how subsurface assets are inspected.

Regional Experiences and Scale

• Historical geothermal in the same Utah area (e.g., older plants) is mentioned.
• Tuscany and New Zealand are brought up as substantial geothermal power producers, with a reminder that even there, geothermal is significant but not dominant.

Skepticism and Meta-Discussion

• A few commenters dismiss the article entirely because it’s on Bill Gates’s site; others praise Gates’s broader energy-tech efforts (geothermal and advanced nuclear).
• Some point readers to long-form essays and podcasts that dive deeper into geothermal economics, fracking-adjacent tech, and grid integration.