Natural gas (not bottled propane) is generally still much cheaper per net BTU in most of the US for heating. I had to make a choice back in ~2005 when I switched from oil heat. At the time - with NG near it's historical highs and my local electricity just 10c/hWh - they were on par, with electric having a theoretical advantage in ideal conditions and near parity in our coldest 2 months of the year. Of course since then electric has gone up 50% and NG has dropped by a factor of 3. To stich now would be prohibitively expensive, though, as the cost to extend the NG line has tripled (to around $15k or more). I'll never make that back in energy savings.