I've done as much research as i can an every site i hit seems to have a different story on my question: "Will a dehumidifier save energy while running your AC through the summer"?
The ones that say "yes" pretty much reason that you usually can raise your thermostat a few degrees because of the lower humidity it will "feel" more comfortable. While they reason that yes AC do dehumidify also but it will put less of a load on your AC system.
The ones that say "no" say AC units doesn't run optimally when a dehumidifier is running (they don't go into details). Also, by design, dehumidifiers heat the air. How much of a difference that makes, i don't know.
That being said dehumidifiers do pull quite a bit of energy (i'm sure not NEARLY the amount of an AC unit though).
I live in zone 5 (central IL). Hot/humid summers and cold/dry winters. I don't need a dehumidifier for the winter (we actually need a humidifier then).
Also, as a lot of you probably already know, current dehumidifiers are some of the most unreliable appliances you can buy. Its one of the few things i know make sure i get an extended warranty for. I'm on my 3rd unit and, one of the reasons i'm here, is to find out if i need to budget for another one. Sure i'm sure there will be days when i could not run the AC and just run the dehumidifier but i don't think there will be enough of those days to warrant a dehumidifier if i really don't need one.