Back when I lived in SC, we had a couple of programmable thermostats. One for upstairs and one for downstairs. We both worked pretty long hours, so we'd leave the house at around 7 am and not get back until 6 or even later. That's around 11 hours where there's no one there. Like most folks, we had some pretty high energy bills in the summer and were always looking for ways to cut those costs.
I found that the SCE&G recommendations were total bullshit. They recommended keeping the house at a slightly elevated temperature (78 or so) when we were away and bringing the temp down when we were there. I regularly had $250 power bills doing this. I ended up programming the thermostats to start cooling at 88 degrees at 6am. Essentially turning them off in the morning before we left the house. I tried earlier, but the house would start to warm too much if I started that at 5am. At 4:30pm, I programmed the thermostats to 72 degrees. By the time we rolled in at 6, the house was at that temperature.
Supposedly, this makes the AC "work harder". But we had new central air put in the house when we moved in and did this for 10 years. No problems. It cut our power bill by $100 a month.
Obviously this wouldn't work for everyone, but if you are out of the house every day for 8 plus hours, this can help you out..
