I do this already, but for the reason that the noise from the fan and the escaping light keeps me awake if it's on through the night. I have a cupboard in my hallway that is a better space to use. I have 7 cats and have their food and cat litter delivered monthly so that currently fills the space, but with some skills honed over the years through Tetris, I reckon I'll be able to do a straight swap and use the the wardrobe (my "grow tent") for the cats stuff and the hallway cupboard for my plants. With proper space management I think I could comfortably grow 4 plants and as it's away from where I sleep, I'm not constrained by when I can or can't use the lights. The greatest benefit from this would be electric usage. Between the hours of midnight through till 7am the price per unit is a quarter of what I pay per unit from 7am till midnight, so I'll pay a quarter of the total for my running costs.