Thanks for this insight. Never thought about this. I'm still on old-fashioned gas so in my case the only difference is one of gas being cheaper per joule even a

Thanks for this insight. Never thought about this. I'm still on old-fashioned gas so in my case the only difference is one of gas being cheaper per joule even after the (in-)efficiency of burning than electricity. But indeed in the heat pump world you get more joules in heating than you put in in Wh of electricity. Still you should amortize the cost of pump per joule of heating. Bulbs were _cheap_.