Programmable thermostats are great for controlling the temperature. Prior to buying ours I would always forget to change the setting on the thermostat before I went out the door to work. Be very careful of the hours you set the temperatures. I went a whole summer without realizing that if I set 72 degrees for 5PM that my programmable thermostat told the air to come on in time to have the house cooled to 72 at 5PM. I thought 5PM is when the air would kick on. This becomes very important if you use the next service.
Srp point of use program will reduce your per kW charge by nearly 50% during off peak hours and a slightly elevated rate during peak hours. Summer peak hours were 5 to 8PM. Be careful to watch your statements for winter hours. Even though we saved hundreds during the summer months I have lost a few dollars over the winter months when the peak hours changed to 5AM to 9AM and 5PM to 9PM
Change your air filters every 30 days. Some filters are made to last longer than 30 days, but the dust still piles up making your air conditioning systems work harder.
Finally, do NOT sign up for the program that charges you the same amount monthly. In Phoenix, SRP will only allow people to sign up for it during the winter months (when power bills are generally next to nothing). This means THEY keep all the extra you are paying in the winter and THEY are collecting the interest on your money. This is the same principal as getting a tax return. If you have a monthly budget, and you should, plug in extra for the power bill in the summer months. By paying the same amount every month you are in effect paying a non interest charging bill before you need to.