A few small thermostat schedule changes can meaningfully cut your SDG&E bill — especially if you’re on a Time-of-Use plan and running an ecobee.
Best practice: Pre-cool before 4 PM, reduce HVAC demand from 4–9 PM, and return to normal comfort after 9 PM. Your ecobee thermostat can help shift more of your cooling to lower-cost hours. Many SDG&E Time-of-Use plans have their highest-cost period between 4:00 PM and 9:00 PM — actual rates depend on your specific SDG&E or Community Choice plan, so check your current rate plan through SDG&E’s pricing plans page.
Suggested Summer Schedule
Morning / Midday — Before 4 PM
74–76°F
On very hot days, consider pre-cooling to 72–74°F before 4 PM, especially while solar panels are producing power.
4 PM – 9 PM — Peak Hours
~78°F
If comfortable, let the temperature rise gradually. Avoid large thermostat changes or repeatedly lowering the setpoint during this window.
After 9 PM
75–76°F
Return to your preferred comfort setting once peak pricing ends.
Don’t turn the AC completely off on a very hot day and then ask it to recover from a very high indoor temperature. Maintaining a reasonably steady temperature is generally easier on the system and gives better comfort than big swings.
Let ecobee Do It Automatically
Set these temperatures as a schedule in the ecobee app so you’re not manually adjusting the thermostat every day. Once it’s set up, the system shifts your cooling load automatically — you don’t have to remember to do it, and you don’t lose the savings on days you forget.
If You Have Solar Panels
During sunny hours, running your heat pump before the 4–9 PM peak period makes good use of on-site solar production — you’re cooling the home with power you’ve already generated, rather than paying peak rates later. Actual savings depend on your specific solar agreement, rate plan, battery storage, and household electricity use, so results vary by home.
Why This Actually Works
Most SDG&E Time-of-Use plans price electricity differently throughout the day, with the highest rates typically landing in the late afternoon and evening — exactly when San Diego homes are working hardest to stay cool. Shifting your cooling load earlier, when rates are lower, doesn’t reduce your total comfort over the day; it just changes when your system does the work. If you’re also curious about what’s driving your bill up in the first place, our piece on why your air conditioner uses so much electricity digs into the other common culprits, and energy-saving AC modes: myths and reality covers which built-in “eco” settings actually help and which don’t.
Frequently Asked Questions
Do all SDG&E plans have the same 4–9 PM peak window?
No. Peak windows and rates vary by your specific SDG&E or Community Choice Aggregation plan. Check your current rate plan in My Energy Center before setting your schedule.
Will letting the house get to 78°F during peak hours damage my comfort?
Most households find a gradual rise to around 78°F manageable, especially after pre-cooling earlier in the day. The key is avoiding large, sudden setpoint changes during the peak window itself.
Should I just turn off the AC completely during peak hours to save more?
No — turning the system off entirely on a hot day means it has to work harder to recover from a much higher indoor temperature afterward, which can offset the savings. A steady, gradual schedule works better than an all-or-nothing approach.
Does this schedule still make sense without solar panels?
Yes. The pre-cool/peak-reduction approach helps on any Time-of-Use plan, with or without solar — solar just adds an extra layer of savings on top by using power you’ve already generated.
Want help setting up your ecobee schedule or checking if your system can keep up with a pre-cooling strategy? Reach out to Omega Air — we can walk through your specific rate plan and system together.
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