How large is your RV? It is possible to install about 750 watts of solar panels on the roof, a few more watts might be possible, but the panels are still pretty large. THey have come down in price a LOT since the 90's. My 400 watt system cost well over $1,500 when new in the 90's, now it can be replaced with 3 each 140 watt panels from this place, $229 each.
SunElec.comIf you have 750 watts of solar, and perhaps a set of 4 golf cart batteries, 440 AH, then you can store enough power and make enough power to run the A/C for at least 5 hours per day run time.
Good luck,
Fred.