One idea I had would have involved judicious planning when I'm was first married. Why are all casseroles etc round? I worked out that you could save so much electricity by putting most of the week's dishes in the oven all at once, if you used square dishes. You should be able to get four on an oven tray.
One with a casserole, one with a pie or a quiche. One with a cake, one with rice and/or a bake (such as a lasagne or Mac and cheese). Etc etc. they would all need about the same temperature and just take slightly different times to cook. They would then keep in the fridge or freezer until needed later in the week, and the square dishes would make storage much more economical, too.
But I only have the standard round Pyrex dishes.
If I am doing a casserole or any other one pot meal. I always make sure at least two things are in the oven. Rice, for example, can go in the oven with water and a lid on, and can be forgotten about, saving on electricity because you aren't heating a hob as well. Heating up a baguette or baking potatoes to go with the meal would have the same effect. Less washing up, and less mess on the hob.