Before spending alot of monies to get Air Conditioners going I'm assuming your MUSIC FEST is allowing the use of generators for extended times. As a general rule most public camp grounds have generator run time restrictions in place and never after 8PM at night...
If the MUSIC FEST is on private land much like NASCAR RACE places are then the local owners set the rules on when you can run you generators...
Here on the East side of the US we run into this all the time with generator run time restrictions in place. Even the NATL FOREST places around us have Generator run time restrictions in place. Out West where alot of DISPERSED CAMPING is available running generators is much relaxed after hours.
Since you have been going here for five years it sounds like it may not be issue for you - just saying it may be something to check on haha...
Roy Ken
