I think Airbnb should find a way to allow hosts to address this.
We recently had a guest rent our apartment in Sofia, Bulgaria, for a few months and the electricity bills skyrocketed during his stay. We suspect that he may have been mining cryptocurrency (like bitcoin) with one or more laptops. I don't know how probable that is, but given the rise of "digital nomads" making their rounds through countries with lower costs of living (and cheaper Airbnb options), I am curious how often this happens. And there's no way to prove that it may have been something like bitcoin mining rather than excessive use of the electric heat.
My current solution (based on very little thought or research) is to resort to threatening the guest with a bad review. I included this notice in our listing:
ELECTRICITY CONSUMPTION:
* Please be mindful about your electricity consumption. Electricity is not free (for hosts or the planet!). Please turn off the A/C or heat when you leave the apartment & turn it off/down during the night. Mining of bitcoin or other cryptocurrency will not be tolerated.
* Note that we check guests' electricity consumption before we leave a guest review. If it is clearly excessive (for example, due to round-the-clock running of A/C or heat or if the guest has been mining bitcoins), we will leave a 1-star review and a very clear public comment about excessive electricity consumption.
Can anyone offer other solutions?