mini oven as ecological/economical solution?

Since I share with a housemate rather than my ex, the electricity consumption of this household has almost doubled.

I am looking at solutions and apart from getting a consumption meter gadget thingie (I'll create another post elsewhere with my questions for this) was wondering if a mini-oven would be one solution.

I rarely use the oven, but my housemate uses it almost daily. The one in the flat is rather large. especially when it is only baking one potato or one of these one-portion ready meals.

Do you know of any of these mini-ovens that make sense ecologically as well as economically? Or is it just because they are smaller, i.e. need less energy warming up that they save money/the world at large .

Any advice? I cannot ask my housemate to plan her meals and use the oven to its full capacity once or twice a week only.

What about a combination microwave? Our adult daughter lives with us, and usually cooks for herself (although we all share meals sometimes) - she does a lot of her cooking in the microwave which does save money. Or would it be possible for you and your flatmate to occasionally cook for each other?

We sometimes cook for each other (about once a week when I am home), but it is not always possible.

We don't tend to coincide for meals either! I know our bills are higher because we're cooking two lots of meals, but it's just the way it has to be for several reasons. A microwave does help, though, because you can bake a potato in five minutes as opposed to an hour in the conventional oven. I haven't actually ever used a combination oven, but my brother has one and finds it very useful. There's also halogen ovens which claim to halve cooking time, but I've never used one of those either (and they look a bit scary!)

I know what you mean about halogen ovens... and if they halve the
cooking time, do they halve the energy consumption or do they use the
same amount a conventional oven would use?

I must admit to not being crazy about microwaves oven. I have (maybe totally irrational) doubts about their safety re health.