[londons_explore]

It uses gas compression through staged compressors to make the hot side, and gas expansion through staged expanders for the cold side, which makes a loop.

Think of it like a scaled up, reversible refrigerator.

I'd like to know if they also have a 'medium temp' tank, since if they do, they can keep the temperatures of the hot and cold tanks constant, and just change the amount of molten salt in them. That in turn means the compressors can be fixed compression ratios, which will dramatically increase efficiency.

[londons_explore]

To follow up here, having read the paper, they have two 'medium temperature' tanks (for the hot and cold side materials, which are different). The turbines do indeed work at constant input and output temperature, and at constant flow velocity and therefore wattage.

The paper suggests changing the pressure of the working fluid to adjust load, but I suspect it is hard to design a turbine to be efficient at a wide range of working pressures, so instead they'll end up with many parallel turbines, and just switch some off to get less energy produced.