I posted this at another forum, but I thought the bright minds on this site might want to tackle this.
My roommate and I disagree on this issue. I'm not sure I'm right, but he's pretty sure I'm wrong. I think he thinks that because that's what everyone else thinks.
It occurs to me that, in the winter when we already have our gas furnace keeping the house at 65-68, it might be cost-neutral to keep our electric oven at 350 at all times.
First, I do recognize that heating the entire house solely with the electric oven would likely be more expensive due to the fact that the electric heating element will not be as efficient as our gas furnace. However, the oven's main power-drain stages are during pre-heating and actual cooking. A significantly lower amount of power is needed to simply maintain the internal temperature when it's empty.
Second, electricity is relatively inexpensive (and semi-green) in our area due to it being 95%+ provided by hydro-power sources. This makes the equation tip towards my favor far more than it would in an average American house that uses electricity from costlier sources.
This leads me towards considering how to conduct an experiment that really finds out the truth.
So far, I've decided that the actual wattage of the oven itself is irrelevant and near impossible to use as a means of deduction. It would be far better and accurate to attach a meter to the oven's power cable and record the power draw on warm-up as well as the average draw during a few hours of empty heat maintenance. I figure a 2 hour sample will provide enough data to determine the average on a monthly basis since the conditions will remain constant all day on every day.
The tough part is determining how much heat the oven adds to the overall temperature of the house, and therefore how much gas use it saves.
This is the part where you tell me I'm an idiot and/or suggest some methods.