Roommates suck. Notes are a good way to take care of things but sometimes you just gotta have an awkward convo if they don't work.
One of my roommates does the same thing, total resource hog. He has an electric heater in his room and he has it up all the way (literally 80 degrees in his room) and instead of turning it down he opens his window for a week at a time. Doesn't turn it off during the day, leaves it on over thanksgiving break/christmas break while nobody is even there. He leaves the oven on like its his job, it has been left on for an entire weekend on more than one occasion. Instead of using the toaster oven for a single slice of pizza he'll preheat the oven for 30mins...then forget to turn it off. Fluffs his jeans for 20 minutes in the dryer daily. Starts the shower then goes and does laundry while it "warms up", followed by a 30 minute shower.
Other roommate has his gf practically living there 5-6 days a week sometimes, and the days she doesn't stay she comes over to do laundry and showers there. Brings her dog and cat which infested our house with fleas for months.
/rant fuck roommates man.