Interesting that they've got Sterling cycle heat pumps that can deal with 600KVA (minus how much actually leaves as MW energy, plus what's required to cool down to operating temperature.
There's at least one company trying to build Sterling cycle heat pumps just as an alternative to current (vapor compression / expansion) tech. So far, it looks to be more efficient, but the high thermal conductivity gasses (hydrogen, helium) needed are problematic to keep inside the system. Current tech solved the issue by sealing motor and compressor inside the 'loop'. That had been a problem, just dealing with seals on a *rotating* shaft. Here, it's a more difficult gas - and *sliding* seals.
Sorry to go on, but if somebody's got this working, it's a big deal...