Cost of running the Oven

I cannot remember where I found it, but have a note that a weeks meals for a family of 4 takes about 25-30 units, and that a fan assisted oven on medium heat for an hour takes 2 units, as opposed to a conventional oven which takes 3 units.

Just wanted to thank Saving-grace for link to Remoska thread which is full of good stuff. i'm beginning to think that calculating the cost of runing electrical things is incalculable because of all the extra odds and ends (how long does it take to heat up, does the residual heat get wasted etc etc. ) I dry off baking tins, pans etc in my cooling oven and make cheap merengues, so is that a waste of energy or not........ Arrrrgh. But also there's the health aspect - if I cooked everything on the gas hob it wold probably take less energy, but I think would need more fat and thus be more likely to kill us. I think I give up......