Comment Re:It doesn't work at scale (Score 1) 33
Fortunately, we have you -- a knowledgeable human, who can propose the right points!
So, I asked Chat about what you said, and asked Chat-GPT to formulate a response that directly addresses your key points.
Let me know if it reads like randomly extruded text, or if it has relevance to your understanding and argument:
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The Campi Flegrei project you’re describing was a natural hydrothermal system, not an engineered superhot-rock (SHR) system, and that distinction matters for both the chemistry and the physics.
A hydrothermal reservoir taps naturally circulating volcanic brine. Its fluid chemistry is whatever the rock has been stewing in for centuries: arsenic, boron, mercury, dissolved metals, HS, etc. The industry learned long ago that natural brines often destroy turbines, foul condensers, and require scrubbing that wipes out the thermodynamic efficiency. Those problems are real, and your experience confirms them.
Superhot-rock geothermal is a different class of project. It does not rely on natural brines, natural permeability, or natural aquifers. SHR / modern EGS systems:
Bring their own working fluid (usually treated water in a closed or semi-closed loop),
Create engineered fracture networks rather than using natural ones,
Operate in a supercritical regime (>374C, high pressure) where heat transport is dominated by convective sweep rather than slow conduction, and
Are sited where mantle heat flux is extremely high (e.g., Newberry), not just where water has accumulated in shallow formations.
The key point is that the problems you encountered at Campi Flegrei — toxic brine chemistry, turbine contamination, and power losses from scrubbing — are specific to hydrothermal geology, not to engineered SHR systems. SHR avoids most of that simply because it doesn’t use the volcanic soup; it uses injected water circulating through a designed heat-exchange zone.
Your numbers actually underline the potential: you were getting ~50 MW per well from a shallow (~350–400C) hydrothermal system with awful chemistry. Modern SHR aims for rock in the 400–500C+ range, with supercritical water carrying far more enthalpy per kilogram and without the brine-chemistry penalty.
Whether SHR proves economical at scale is still an open engineering question. But the Campi Flegrei outcome doesn’t generalize to SHR any more than the problems of early natural-steam geothermal plants generalized to modern binary-cycle systems.
Does this distinction make sense from your point of view?