I (self installed) a heat pump and I love it. Sure, it's not really efficient (COP ~1.5) when it's -10C outside, but this happens 1 day per year. Most of the t

I (self installed) a heat pump and I love it. Sure, it's not really efficient (COP ~1.5) when it's -10C outside, but this happens 1 day per year. Most of the time the COP is around 4: that means that it uses 1kWh of electricity to produce 4 units of heat. My electricity kWh is .17cts, so the final heat kWh is ~ 0.17/4 = 0.04cts, which is awesome. Using france's electricity production mix, that means that I can heat my house for 60/4 g/kWh = 15gCO2/kWh.