Sure they can charge, it’s only $0,57 kWh here during peak. I’ll put a 50 gallon drum of gas with a pump out there too, with a key for the bathroom and a list of available snacks, beer and the WiFi password. Better heat the pool and put out some towels.
I'm on a TOU rate, but peak is not quite that high. But even if it were $0.57/kwh, my Wall charger max rate is 32A, so at peak 7.5 kw, they'd draw down at most $8.50 in two hours.
@jjrandorin expressed my sentiments perfectly. Either I'd let someone charge for free for a few hours, if they had some bind that would otherwise leave them stranded or horribly inconvenienced, or I wouldn't let them charge at all if there weren't an urgent need. If they can't get to where they need to be with 15 kw in two hours (should be about 40-60 miles range),or to limp to a better/faster charger with that, then they have bigger problems than I could really help them with.
If they insisted on paying, or getting my info to pay me later, I'd just tell them to pay it forward later to someone who was in a bind. It's really no different than if I were in line behind someone at a cashier at a fast food place, or grocery, and they realized they didn't have their wallet, or the right form of payment. Often it's not that they can't afford it, they are just in a bind. In fact, it happened a few months ago at youth sports competition, it was cash only for spectator wristbands, and one parent I didn't know only had credit cards - would've taken him at least an hour, maybe two, to go somewhere to get $10 cash, including huge car queue to get back into the parking lot, just to watch his kid play.
But I do live in a fairly quiet, calm suburb, and though just a minute from a freeway off-ramp, there are very few strangers who enter the neighborhood randomly, otherwise they're likely either lost or desperate. If I lived in a busier, urban area, that had a lot of random traffic or random crime, I'd probably be less trusting of a random stranger's request - not because of $8.50, but out of concern of being turned into a victim of some larger crime...