Comment by Eddy_Viscosity2

Heat pumps could actually lead to a net increase in energy usage in northern areas because they can double as air conditioners for cooling in the summer. Normally homes in northern areas don't have AC and you just have to get through the relative short period when its hot enough that it would be nice to have. But with heat pumps, you just switch to AC mode. Also, those periods of hot weather are getting hotter and longer in duration.