It’s way too much for just electricity. People did some calculating of the kilowatt hours last time you posted this. Reread their answers.
I think you’d be more justified in having him pay for part of your rent and a share of your internet, since he’s there so much, even if he doesn’t stay overnight. When a roommate you didn’t agree to share your home with is there for forty hours a week, he owes rent and internet at a minimum, and maybe a share of total utilities.