This sounds like cool tech, and the re-use of the existing generation assets is clever, but just running costs of the steam part of an existing plant struggles to compete on a financial basis with wind turbines and solar PV so it'll probably only ever be a niche thing.
Shared ground loops connected to heat pumps are a more boring tech with more potential to have a global scale impact.
Assuming that people commit to buying 24/7 carbon-free energy at any price, on-demand generation like geothermal will be quite valuable during the times when wind and solar are underperforming.
So geothermal will mainly compete with nuclear and storage, not wind and solar.
Yep, and like nuclear, it has a high up front cost that needs to be amortized over near constant use to be viable which means it prices itself out of that role pretty quickly compared with say green ammonia fired peaker plants that mostly incur costs when actually used and also use the green energy being produced in large quantities.
I wasn't even counting the combustion part, just the heat to steam to electricity part (common to coal and nuclear plants).
I had assumed they would need to transfer the heat rather than pipe geothermal steam directly into the turbine, but either way, solar and wind is very cheap and hard to compete with. Even magical free energy connected to a steam turbine struggles when you do the sums, which is the baseline before you start including cost and risk from super deep drilling.
Shared ground loops connected to heat pumps are a more boring tech with more potential to have a global scale impact.