> The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required.[1][2] Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
That 'up to 3 times' is a very generic sounding Carnot cycle number. It's about the upper limit for heat pump performance, so it's not a very meaningful number IMO.
At 1000℉ (811K) the maximum achievable COP against an ambiental (300K) source is about 1.6, limited by the second principle of thermodynamics.
And that's the absolute theoretical maximum, you would be happy to breakeven in practice. Unless you have access to waste turbine exhaust, geothermal water, solar collectors or something along those lines, I don't see any practical application where the marginal energy savings would recover the capital costs of the pump at 1000F.
But hey, they have software modeling and venture financiers, so I'm sure they are not overselling it and it's all excellent and double plus innovative.
They may need CO2 free process heat at 400 ℉, and use a thermal storage at 800 or 1000℉.
Our heat engine can pump more heat than resistive heating (heat pump mode) during charge. During discharge, it can convert heat to electricity from 1000F to 400F, and use that electricity to power a heat pump (and produce more heat).
We can "magnify" the storage both ways.
We don't need to go to 1000F soon, there are so many applications we can decarbonize along the way. We could lower the temperature and do cooling+heating at the same time for example.
the maximum is given by the carnot cycle, which has COP=T_high/(T_high-T_cold) so from room temp 25°C to 250°C it is 2.3, but this is the theoretical limit
Which is why for some pool heat pumps you get claimed numbers of around 9, with the fine-print that the air temperature has to be higher than the water temperature.
