Saturday, January 3, 2009

Comparing Electricity and Oil for Home Heating

In June, when world oil prices were peaking, I did a study of the relative merits of electricity and oil for heating. In spite of those results, which favored oil, I tried heating my house with electricity in November. It worked better than I expected, so I tried it again in December.

To summarize my results, I use about $16 of electricity to heat my home on a cold winter day. That compares to about 8 gallons of heating oil. It appears that 1 gallon of oil is about as good as $2 of electricity — much less than the $5.454 I had calculated.

Why such a big difference? I know some of the reasons, and I can speculate at some others.

  • With electricity, I am leaving the dining room unheated. In principle, that ought to save more than 10 percent. The central heating system I use for oil doesn’t work so well if you start closing rooms off.
  • My price of electricity is now 13.9¢, 15 percent less than the 16.2¢ I was paying in the summer.
  • The high-efficiency oil heater might be less efficient than I thought. More of the heat it produces might be going up the chimney. A small part of the oil might be going up the chimney unburned.
  • The traditional heating system concentrates heat around the exterior walls of the house. This eliminates drafts, but maximizes heat loss through the windows. With electric heat, I can place the heat sources near the center of the house.
  • There is some variability in heating results because it is affected by weather factors that aren’t completely measured. For example, I think this December had less daytime cloud cover than usual, resulting in more solar heating.

If I stretch all of these factors, they might be enough to account for the differences I am seeing. But more likely, there are other factors I have not considered.

The drop in crude oil and natural gas prices, to half of what they were a year ago, means the heating crisis I was anticipating did not arrive this winter. At this point, oil is still a viable heating fuel. But the prospects for oil (if world oil prices fell because of the U.S. economy, they may roar right back as soon as the economy recovers) still argue against any more oil heat installations, and for a transition away from oil for heating.