what do we call the heat generated by a current passing through a resistance?
Let us differentiate.
The number of WATTS a circuit will use, is: W=IV
Let us also consider the amount of heat you will realize from that amount of power.
H=Heat (in BTU's)W=Power into a heating circuit
We see that resistance electrical heat is only about 3/7 as efficient as it should be. (precise figures are a bit different: I have rounded up here).
Hence, we see the efficiencies realized by such as heat pumps, which deliver 80-85% of the energy input into heat inside your home depending on the temperature outside your home.