I actually used the efficiency specs for our heat pump to calculate cost to operate at various temperatures and was surprised to find that operating our heat pump is actually less expensive than running our pellet stove.

Actual use correlated well with the calculated savings to use the heat pump too.

I’ll switch over to the pellet stove only once temps fall to below 20F. It’s nice because where I’d buy and burn 3 tons of pellets in a winter, now I only go through a ton. Newer heat pumps are even more efficient than my system and can show saving even in subzero temperatures.