I don't know. Something about this doesn't sit right with me. I just don't find 'bitcoin is vulnerable because sacred rock' to be a convincing argument.
Our route to limitless free energy is probably commercial fusion reactors, which always seem to be about 50 years away from viability. Perhaps we'll get there one day, but even so it would be a steady flow of free energy with some maximum finite throughput, rather than the instant availability of infinity.