[OJFord]

For the curious non-American that's 538 & 182.

Is that basically 'just' a different refrigerant (and whatever necessary engineering to cope with it)?

[iamthemonster]

In case you don't get a reply from the parent commenter, it is basically putting many heat pumps together. So one heat pump steps the temperature up a bit, and your next heat pump takes that warm fluid and bumps up its temperature and so on. You don't want to do large changes in temperature all in one go because it's inefficient - heat pumps love small temperature differences.

[franckl]

We dont use refrigerant and it is a single HP with a 930F lift (so huge temperature difference between source and sink temperature).

It is more than a heat pump, it is a new Stirling engine architecture, so it can run in reverse (heat to electricity) with an exceptional efficiency