Energy expenditure, I guess I don't worry about it to the point of being blazing hot or freezing cold just to save energy (I can take *some* heat though, have some heat tolerance, but it gets hotter than that, and I don't have any cold tolerance whatsoever). So I turn off lights and the shredder when not in use whenever I remember. I barely even own kitchen appliances beyond the basic stove and fridge. I have the computer equipment on a power strip I switch off when not in use. I try to buy Energy Star when I'm buying electronic or electrical devices. I pay for the Green (wind) power as well. And beyond that I guess I don't worry about it. Because most of the advice on saving power is utterly useless, it's advice for homeowners who can modify their whole building, and so for renters like me it doesn't have anything to offer.