Heat pumps are 300% - 500% efficient, enough to represent a 66% to 80% savings on their own. Adding insulation reduces the total amount of heating necessary, plus heating oil and electricity aren't priced the same per-unit of energy.
This is not unbelievable in the slightest. Perhaps if you find it surprising, you should ponder where your reasoning got hung up.
Heat pumps are 300% - 500% efficient, enough to represent a 66% to 80% savings on their own. Adding insulation reduces the total amount of heating necessary, plus heating oil and electricity aren't priced the same per-unit of energy.
This is not unbelievable in the slightest. Perhaps if you find it surprising, you should ponder where your reasoning got hung up.