Our neighbor recently told us how they saved by a new strategy of cooling their home. They crank the A/C at about 7:30 am to 65 degrees F. From Noon till 7 pm the A/C is off all together. From 7 pm to 7:30 am they put it at a comfortable setting.
APS, our power company, has us set up to have the most expensive energy to be between noon and 7 pm. This is because energy costs more for them at this time because it is the peak energy usage in the market. It does not cost them nearly as much to provide it outside of these hours because their power plants are working at less than their full capacity. It costs them more in the peak hours because they would either need to invest in more infrastructure to generate more electricity or buy it from somewhere else at a premium because it is likely a peak time there too.
I am not sure how much we will save, but it seems to be a win-win for us and our power company.
By the time noon comes, our temperature in the house gets to about 69 F. By 7 pm we are at about 81 F. Then we keep it at about 77 the rest of the night.