This just isn't accurate - you use less electricity yes, but not less energy.
1 kWh of electricity run thru a resistive heater will generate 3412 BTU
1 Ccf of gas contains the equivalent energy as 29 kWh, but will only generate 8.7 kWh when run thru thermal generation (assuming 40% efficiency and 10% transmission losses).
If you're just trying to make heat, directly burning the gas will consume much less energy - and make fewer emissions - than gas > electricity > heatpump > heat.
If you're trying to compare the caloric content of two forms of energy, knowing what you can get out of the energy by itself is helpful.
In the end, the HP will be up to 30% more efficient than strip heat (in my case the crossover point is under 10f where strip heat is cheaper to operate).
I built a breakdown chart showing cost per kWh for both heat pump and strip heat, then added gas to it as a comparison.
1 kWh of electricity run thru a resistive heater will generate 3412 BTU
1 Ccf of gas contains the equivalent energy as 29 kWh, but will only generate 8.7 kWh when run thru thermal generation (assuming 40% efficiency and 10% transmission losses).
If you're just trying to make heat, directly burning the gas will consume much less energy - and make fewer emissions - than gas > electricity > heatpump > heat.