[cmurphycode]

I was curious about this a while ago and did some napkin math.

Natural gas is roughly $15 for 1 million BTU. There are 3412 BTU in a kwhr, so if you heated resistively, you'd need 293 kwhr to get 1 million BTU.

In my area, which I feel has pretty high electricity cost, we pay $.24 per kwhr, so that'd be $70.

Therefore, you need a 70/15 (4.666) COP for your heat pump to match natural gas by price. My understanding is that that would be an unusually high number for cold weather conditions.

[lsllc]

The State of NH Office of Strategic Initiatives has a nice Fuel Price comparison page that they keep up to date (and are adjusted according to cost per MMBTU):

https://www.nh.gov/osi/energy/energy-nh/fuel-prices/index.ht...

You can see that as of June 2, measured at $ per MMBTU (million BTU):

  Natural Gas           $8.31
  Oil                  $17.62
  Propane              $32.93
  Wood pellets         $21.92
  Resistive electric   $48.84
  Air src heat pump    $18.74

The fossil fuels are all measured assuming 80% heating efficiency, whereas for propane or natural gas you might well have a high efficiency unit up to 97% which gains you a bit more savings.

These prices may vary depending on location and also I think natural gas isn't that common in NH as it's a mostly rural state.

[cmurphycode]

Holy moly. That price per million btu is a lot less than the number I stumbled across. Makes it even more obvious.