Then it depends on what portion of the electricity mix is CCG instead of simple gas turbines or coal, what’s the actual efficiency of heat pump (you won’t get 3

Then it depends on what portion of the electricity mix is CCG instead of simple gas turbines or coal, what’s the actual efficiency of heat pump (you won’t get 300% when it’s subzero temperature) etc. Point is, air source heat pumps are really not much, or even necessarily at all more efficient than just burning gas directly at home, it all depends.