I have been thinking ahead about staying warm next winter using the least amount of watts possible. I might be able to get away with powering that off my solar system, if i can find the right combination of watts.
Caveat: I do have a very small studio - 150 sq feet, and it's well insulated. I made it through last winter with just a space heater. I also have mild winters that only hover around freezing or sometimes dip to the 20s.
I recently read a thread on Permies.com about creating a heat bubble around the places you use in your home, instead of heating the entire house.
In my case, I would want a heat bubble around the computer, one on the bed, and maybe one to sit and watch TV (which I don't do often, really).
For the computer area, I could easily wear socks, a sweatshirt and a hat to start with. Then I could either get a heated keyboard/mouse set or just use some USB fingerless gloves. I found a $5 set of USB heated gloves on Amazon recently and did order those.
With heating the hands, I'd also want to sit on a heating pad (again, a USB one would be great), and have some kind of heating pad for my feet. There is also the option of USB heated slippers, but i think I'd be happier with socks and a heating pad. It will eventually come down to the watt combination, I am sure. Whatever ends up being the lowest combination that still keeps me warm.
I am also looking into 'personal heaters', which are like tiny space heaters that heat a body part. I found a cute USB one that I could either use for feet or hands/face, that uses only 200 watts. While that uses more than a set of heated fingerless USB gloves, it's a WHOLE lot less than the typical 1500 watt space heater.
I'll be reading about these little heaters and keeping an eye on the reviews. I don't like being cold at all, so I think I will be a good test subject. And i do have plenty of time to work on this - summer isn't even here yet.