I too had to break my 3-day reservation into 3 single night reservations. When the hotel questioned me, I explained that I wasn't sure if I would need the final night and wasn't going to give in to their penalty. I also casually mentioned that better they deal with paperwork than me.
Interesting though that the reservation confirmation I received via email (I booked online) never mentions any indication of early departure or energy surcharge (San Diego hotel). Wondering if I could use that confirmation as validation of they did not inform me of their penalty fees?