This is a good conversation I have been looking for. I am also a host in Thailand, Phuket. I am renting private pool villas, and electricity cost can vary a lot depending on the guests - and we know Electricity is expensive in Thailand. Some put on all airconditioners in the villa and leave the doors open to the terrace for their whole stay, and the electrical costs can be enormous.
I have, since I started 3 years ago, charged cash for electricity when guests check out. I inform them in my listing, again on check in when we read the meter together and they sign a papper with the electrical reading, and I collect the money when we read the meter on check out.
This is quite a job, and some guests are complaining about that they have to pay. But so far everyone has paid.
My option would be to calculate maximum electrical usage and add it on the rental price fore every guests, and that does not feel fair and then my prices will not be competitive.
I whish airbnb could include this somehow in the Security Deposit, so that we would have the right to charge the electricity through airbnb from the security charge on check out.
