I have a spreadsheet for my energy use.

[JoM]

I'm a switcher offerer too. John often leaves the under unit lights on in the kitchen while we're sat in the living room on the next floor up and it drives me mad.
Tom's the worst though, and when he was working at McDonalds and getting in at 2am there was many a morning when I'd get up and find the landing and hall lights on as well as all of the kitchen lights (under unit lights, ceiling pendant and four spot lights).