Green Energy is generally contrary to the laws of physics in this sense. It's one step forward and three-to-five steps backward.
Heat pumps can have coefficients of performance (joules of cooling provided over joules of energy consumed) between 2.5-5 (going down as outside temperatures drop).
In most situations, it’s more efficient to burn the gas for electricity and then put it into a heat pump than to burn it directly for heating.
In the very coldest situations, where the heat pump less effective, then you may use the resistive heating to augment it.
And “green” tech is about changing power generation sources so that, even if you have some more inefficiency, it’s not polluting the planet or running down finite resources as much.
And if you mean electricity _generation_ is 50%, well, say so. That's a completely different topic, and electricity generation method are varied enough to make any single number meaningless. How do you calculate efficiency of hydro?
Electric heaters are 100% efficient in transforming joules to heat. The powerplant/transmission lines are the issue in this case.