I made a note for myself to go do this math. You beat me to it and answered the question. Thank you :) I vaguely recall I did some back of envelope math a coup

I made a note for myself to go do this math. You beat me to it and answered the question. Thank you :) I vaguely recall I did some back of envelope math a couple years back and determined that a natural gas powered heat pump was actually more efficient (in terms of emissions) based on my grid power source mix. Solar breaks that equation obviously.