Heat pumps were originally designed to cool. There is a point when the cost of electricity makes any heat pump more costly to run than either gas or oil. That point is somewhere around 14 or 15cents KWH. Solar power is being purchased for from 38 centsKWH to 75cents KWH. Heat pumps because of their low efficiency in minus 10 weather run 3 quarters of the time 24 hours a day. Ontario prices for electricity have taken away any advantage heat pumps deliver. Carbon taxes may even this out, only time will tell.