Gas phase change systems in practice are up to about 60% efficiency (relative to an idealized carnot cycle), magnetocaloric systems in labs have been something

Gas phase change systems in practice are up to about 60% efficiency (relative to an idealized carnot cycle), magnetocaloric systems in labs have been something like 70%, and elastocaloric 80%. Edit: And just for reference peltier devices are usually 10-15% efficiency on this scale. So I suppose this new one is somewhere in the 20-30% range.