Not exactly the same thing as free coffee, if selling coffee if the basis of your business.
There are many hotel chains that have free breakfast, and if you are a frequent guest they might give you a reduced rate or occasional free room.
The cost of electricity @ a hotel to charge a Model S over-night should not exceed $10, unless the local electricity rate is bonkers (like Hawaii).
Starbucks does NOT charge extra for cream, milk, sugar, spices, et al to be added to their coffee.
I am not aware if they would have a problem if you brought in your own coffee and then proceeded to add cream, milk, sugar, spices et al from the Starbucks counter (but I would imagine they eventually would say something.)