@Julien887 We deal with it via our nightly rate. I don't think guests want to risk being charged for power and, in the UK, it is arguably illegal to do so unless you have provided an EPC to the guest that shows what the property costs to heat and light.
I think it's the same all around the world, here in Thailand electric has always been expensive,
We used to charge extra for electric we didn't hide it, it was in our listing and when guest arrive they sign our contract it's on there we read the meter together, we was getting bad reviews because of it and a few arguments over it at the end.
We decided to up the rate to cover it, No headaches