When did you last replace your air conditioner.  If it has been 15 years or more, studies show that you are spending about 50% more than you should cooling and heating your home.  New standards in efficiency make your new systems so much more cabable of cooling your home in the summer that your bills really drop. New thermostats which learn when you  are at home and when you are not can manage your temperatures so that you are cool by the time you get home, or you can simply log in and tell your system what temperature you want it to be when you get home.