Bob Minchin wrote:

I would imagine you can get a bit more energy transfer but a much more
complex system.

I see comparisons where the payback for gas vs thermodynamic hot water
is 30 years, so they make it look justifiable by assuming the boiler
needs replacement after 15 years, they seem to assume the thermodynamic
system won't need replacing inside 20 years.

https://www.greenmatch.co.uk/solar-energy/solar-thermal/thermodynamic-panels#cost

But then, their understanding of power vs energy is summed up by "uses
360 watts an hour"