From a technical perspective, this is why a colder than average winter will affect (air-source) electric heat pumps more than resistance or fuel sourced heat. As the outside temps go down, the efficiency decreases in a heat pump, so the curve is non-linear. For electric resistance and fuels, the outdoor temperature has a near zero effect, making the increase in cost linear.
Not that it matters too much. Electricity costs in most of the US are relatively stable whereas fuel costs can swing by a factor of five or more from year to year ($2/MMBTU to over $12/MMBTU in the last decade). Oil doesn’t play much into heating anymore, but it can also swing by more than a factor of two (From a low of $2/gal to over $5/gal in the last decade). Electric, though, is up by 25% over the last decade (on average) and varies by less than a a couple percent from year to year, slowly increasing at around a 2% average rate.
From a technical perspective, this is why a colder than average winter will affect (air-source) electric heat pumps more than resistance or fuel sourced heat. As the outside temps go down, the efficiency decreases in a heat pump, so the curve is non-linear. For electric resistance and fuels, the outdoor temperature has a near zero effect, making the increase in cost linear.
Not that it matters too much. Electricity costs in most of the US are relatively stable whereas fuel costs can swing by a factor of five or more from year to year ($2/MMBTU to over $12/MMBTU in the last decade). Oil doesn’t play much into heating anymore, but it can also swing by more than a factor of two (From a low of $2/gal to over $5/gal in the last decade). Electric, though, is up by 25% over the last decade (on average) and varies by less than a a couple percent from year to year, slowly increasing at around a 2% average rate.