If you're on a Time-of-Use (TOU) plan with Southern California Edison, you know that electricity costs nearly double between 4:00 PM and 9:00 PM. Coincidentally, that's when your house is hottest.
The mistake most people make is turning their AC on right when they get home at 5:00 PM. This fights the heat of the day using the most expensive electricity possible.
The Strategy: Super-Cooling (Pre-Cooling)
Instead of cooling the air, you want to cool the structure of your home (walls, furniture, floors) when electricity is cheap.
The Schedule to Program:
- OFF - Peak (Until 1:00 PM): Set to 78°F. Electricity is cheap, but solar gain is low.
- Pre-Cool (1:00 PM - 4:00 PM): Set to 72°F or 70°F. This runs the AC hard while rates are low (Off-Peak/Super Off-Peak). It freezes your house into a thermal battery.
- Peak Hours (4:00 PM - 9:00 PM): Set to 78°F or 80°F. Because your house is already freezing cold, the AC won't turn on for hours. You are "coasting" through the expensive period.
- Overnight (9:00 PM+): Set back to your preferred sleeping temp (e.g., 75°F).
By shifting your usage to the early afternoon, you buy your comfort at a 50% discount.
Does This really Work?
Yes. A cold house takes hours to heat back up. Even if it's 105°F outside, a home super-cooled to 70°F at 4 PM might only drift up to 76°F by 8 PM, meaning your AC stayed off during the entire peak pricing window.
Need a Programmable Thermostat?
We install WiFi thermostats that make this schedule easy to set from your phone.
Upgrade My Thermostat