Why do guests leave all lights and air conditioning on when they leave?

Guests don't pay attention to consumption because they pay a fixed amount and there are no consequences to leaving the lights or air conditioning on. A note on the door therefore usually doesn't work, because nothing changes in their bill. With a metering module and pre-purchased electricity credit, the guest sees their own consumption during and after their stay, which makes them more inclined to turn off appliances. This doesn't solve everything, but it restores the link between consumption and consequence, and is especially valuable for multiple properties with stays of a few days to a week.