The power company could publish this data. I was able to get a flat rate quote on a property that I didn't live in yet using an online tool from Georgia power.

The power company could publish this data. I was able to get a flat rate quote on a property that I didn't live in yet using an online tool from Georgia power. It's basically the previous year energy cost divided by 12 and a 5-20% markup depending on past annual variations. It doesn't exactly equal efficiency but I knew what I could pay for an entire year of power.