Cooking for Free in the Winter

In the last week there have been lots of blog and news activity around the subject of compact fluorescent lights. (Lawmakers are debating whether they should ban conventional bulbs--I am against the ban, but think CFLs should be encouraged) This is a subject I do not want to re-hash here, but there was one aspect which was interesting:

Some commentators wrote that they wouldn't save any energy because they heat their house with electric and so the waste heat from incandescent bulbs saves their furnace from working that little extra-bit. I think they are absolutely correct, but very few homes are heated that way because electricity is much more expensive than gas or oil on a btu basis. Electric heaters cost a lot less to install than furnaces and the associated plumbing or duct-work, so even though inefficient, plenty were built. In fact, our house in Vermont originally had a wood stove and electric heat as a back-up. The owners before us must have found the effort to heat with wood tiresome and the cost of electricity burdensome, because they installed an oil furnace. In the four years we were there, we heated almost totally with wood.

Getting to the point: Lots of houses and most new construction are made to heat with natural gas, as is our current home. We also cook with a gas stove. In the winter, any heat given off by the cooking stove will save the gas furnace that amount. So in the Winter cooking is for free. The summer is another matter: Got to pay for the gas to cook with and then pay again for the electric energy to pump that heat outside.

In Vermont, we used the inverse calculation: If the wood stove was running, we would use it for cooking and save some electricity.