IMM wrote:


It all depends on usage. Light usage, which is most domestic if you heat,
cook and DHW on gas, it is best to use the battery method topping up when
required. You are right in that the best usage is from large users. But
the inefficiencies of the IC engines is still there.





Not with CHP, because the waste heat isn't wasted.
Also an IC engine at constant load cand be rin far more efficiently than
one that is starting and stopping all the time.