Good use if energy? Not really. While better than mining and wasting the heat, it would be more energy efficient to use heat pumps and more insulation. Just less profitable.
So insulation wise, the house is a listed cottage so there isn’t much more that can be done to insulate it.
As a thatched cottage you can’t put solar heat pumps on it so the only option is ground source heats pumps which would cost £30000 which is just unaffordable.
By heat pump i meant an air conditioner in reverse. this should be possible without a permanent installation affecting the cottage.
Very interesting project! I'm interested to see a writeup of how it's performing in like 6 months.