I concur with @Lenore22. How do you want to represent your property? Personally- I would leave information about saving energy in the guest book or house rules in a polite way if this was important to me. Example: With rising prices everywhere, we do our best to stay competitive (or keep rates as low as possible) by conserving energy. Here are a few tips we apply: Shutting off lights when leaving a room, turning the temperature to xx when leaving on outings for the day, etc." Best of luck!
Vanessa Mullings