SDG&E Time-of-Use Rates: How to Actually Save With Them
SDG&E’s on-peak hours are 4 p.m. to 9 p.m., every day of the week including weekends. The cheapest hours — super off-peak — run midnight to 6 a.m. and again from 10 a.m. to 2 p.m.
On the standard TOU-DR1 plan, super-off-peak power costs about 27¢/kWh against about 58¢/kWh on-peak. The same kilowatt-hour costs more than twice as much at 6 p.m. as it does at noon.
Capturing that gap means moving flexible load out of a five-hour window every evening. It is hard to do by hand and straightforward to do automatically.
This guide explains how SDG&E’s residential time-of-use rates work, where the savings are, and two ways to go after them.
How SDG&E time-of-use pricing works
SDG&E splits the day into pricing periods, and the price per kilowatt-hour changes depending on when you use power. The expensive window — on-peak — is 4 p.m. to 9 p.m. every day, including weekends. That’s the stretch when grid demand is highest, so it’s when electricity costs the most.
Most of SDG&E’s residential plans share the same three time periods:
- On-Peak — 4 p.m. to 9 p.m. (the expensive window, every day)
- Off-Peak — 6–10 a.m., 2–4 p.m., and 9 p.m.–midnight
- Super Off-Peak — midnight to 6 a.m. and 10 a.m. to 2 p.m. (the cheapest hours; midday is cheap because of abundant solar on the grid)
Every SDG&E plan side by side: TOU-DR1, TOU-ELEC, EV-TOU-5 and the rest
SDG&E offers nine residential rate plans. Here’s the full lineup with approximate summer prices (¢/kWh, Tier-1 / below-baseline). These are drawn from SDG&E’s tariff sheets effective in 2026. Always confirm your exact numbers on SDG&E’s pricing plans page, since rates change and depend on your baseline allowance, season, and whether you buy generation from SDG&E or a Community Choice Aggregator like San Diego Community Power.
| Plan | Who it’s for | Super Off-Peak | Off-Peak | On-Peak |
|---|---|---|---|---|
| TOU-DR1 | Standard residential plan | ~27¢ | ~36¢ | ~58¢ |
| TOU-DR2 | Simpler 2-period plan (no midday discount) | — | ~31¢ | ~58¢ |
| DR (standard) | Non-time-of-use, flat tiered | flat ~41¢ (Tier 1) ~52¢ (Tier 2) | ||
| TOU-ELEC | EV, battery, or heat-pump homes | ~35¢ | ~39¢ | ~72¢ |
| EV-TOU-5 | EV owners (whole home) | ~13¢ | ~50¢ | ~79¢ |
| EV-TOU-2 | EV owners (whole home, older plan) | ~31¢ | ~56¢ | ~85¢ |
| DR-SES | Households with solar | ~35¢ | ~44¢ | ~74¢ |
| TOU-DR-P | TOU-DR1 + Reduce-Your-Use event days | ~31¢ | ~38¢ | ~43¢ |
| EV-TOU-5-P | EV owners + Reduce-Your-Use event days | ~12¢ | ~48¢ | ~74¢ |
A few things worth knowing:
- The “-P” plans (TOU-DR-P and EV-TOU-5-P) have lower everyday peak prices, but add a $1.16/kWh surcharge during “Reduce Your Use” events — a handful of high-demand days each year when SDG&E asks customers to cut back. They reward you for shifting load on those days and penalize you if you don’t.
- EV-TOU-5 has the widest swing — roughly 6× from super-off-peak to on-peak. That’s the single biggest reason to automate if you drive electric.
- Super-off-peak includes midday (10 a.m.–2 p.m.) on most plans, not just the overnight hours — useful if you have solar or a battery.
The headline across all of them: when you use power matters as much as how much you use.
Where the savings are
The savings come from moving flexible loads out of the 4–9 p.m. peak and into the cheaper hours:
- Charging an EV. On EV-TOU-5, charging a 40 kWh top-up during super-off-peak instead of on-peak is the difference between roughly $5 and $32 for the same energy. Over a year of regular charging, that adds up fast.
- Cooling your home. San Diego’s hottest hours overlap the peak window. If your AC can do most of its work before 4 p.m. and let the house coast through the evening, you shift a big chunk of usage into cheaper time.
- Heating water and running the dishwasher or laundry outside 4–9 p.m. — smaller individually, but they’re easy wins.
None of this requires using less energy. It’s the same comfort, the same clean clothes, the same charged car — just timed against the rate.
The core move on any SDG&E plan: pull flexible load out of the 4–9 p.m. peak (circled) and into the cheap midday and overnight hours — pre-cooling, leaning on your own solar, and coasting through the expensive window.
How to capture it: by hand vs. automatically
By hand, the playbook is: pre-cool the house in the early afternoon, set the EV charger to start after midnight, and avoid big appliances from 4 to 9 p.m. This works, but it’s a daily chore and it ignores tomorrow’s weather, which decides how much pre-cooling actually pays off. Miss the window on a hot evening and you give the savings right back.
Automatically is where it gets practical. Hungry Machines connects to your setup and builds an optimized schedule for your HVAC, EV charger, water heater, and home battery each night. It looks at SDG&E’s rate schedule, tomorrow’s forecast, your solar production, and a model of how your specific home holds temperature. Then it pre-cools and shifts loads so you ride through the 4–9 p.m. peak on stored comfort and cheap overnight energy. You set the comfort limits; it handles the timing.
The same idea, running on its own: Hungry Machines pre-cools the office ahead of the 4–9 p.m. peak — note the price axis climbing toward $0.68/kWh — then lets the room drift up through the expensive hours while staying inside the comfort band. 31% off that day’s cooling cost.
Most homes on aggressive time-of-use rates can trim 10–25% off their bill this way without feeling a difference indoors.
Do peak rates apply on weekends?
Yes. SDG&E’s on-peak window runs 4 p.m. to 9 p.m. every day of the week, weekends included. There is no Saturday or Sunday exemption on TOU-DR1, TOU-DR2, TOU-ELEC, or any of the EV plans — the price at 6 p.m. on a Saturday is the same on-peak rate you pay at 6 p.m. on a Tuesday.
Most people assume the opposite, and it costs them. On TOU-DR1 the gap between super-off-peak and on-peak is roughly 27¢ against 58¢ — so a load you run at 6 p.m. Saturday instead of 11 a.m. Saturday costs a little over twice as much for the same energy. A 6 kWh dishwasher-plus-laundry Saturday afternoon is about $1.60 at super-off-peak and about $3.50 at peak.
The flip side is genuinely useful: because the windows never move, the cheapest hours are identical seven days a week — midnight to 6 a.m. and 10 a.m. to 2 p.m. There is one schedule to learn, not two, and a weekend is just another day to run it.
Common questions
Is time-of-use worth it in San Diego?
For most homes with an EV, air conditioning, or an electric water heater, yes — and SDG&E’s numbers are steep enough to make the case without hand-waving. On TOU-DR1 the spread runs about 27¢ super-off-peak against about 58¢ on-peak, so the same kilowatt-hour costs more than twice as much at 6 p.m. as at noon. On EV-TOU-5 the swing is roughly 6×, from about 13¢ to about 79¢.
The threshold question is how much of your usage you can actually move. An EV is the clearest case, because the charge has to happen but almost never has to happen now. Cooling is next, since a pre-cooled house coasts.
If your consumption is small and mostly inflexible — lights, a laptop, a fridge — the savings are real but modest, and a simpler plan may suit you better.
Do I have to give up comfort during peak hours?
No. The goal is to do the work early and coast, not to sit in a hot house from 4 to 9 p.m. A home that has been pre-cooled through the cheap midday window typically drifts only a couple of degrees across the evening, because the building envelope and the thermal mass inside it release stored coolness slowly.
That is the whole mechanism, and it is why the approach is physical rather than a matter of willpower. You are using the house as a battery you already own.
How much drift you actually get depends on your insulation, your windows and how hot the day is — a leaky 1960s house coasts less well than a tight new one. The honest framing is that comfort limits are an input, not a casualty: you set the range you’ll accept, and the schedule works inside it.
What if I forget to shift my usage?
That is exactly the problem automation solves, and it is the usual reason time-of-use plans underdeliver. The rate rewards a decision you have to make correctly every single day, and people are reliably bad at that — not through carelessness, but because the right answer changes with tomorrow’s weather.
A schedule that runs nightly doesn’t forget. It also does something you realistically cannot do by hand: it works out how much pre-cooling tomorrow actually justifies. Over-cool on a mild day and you have spent money to save less; under-cool before a hot one and the AC runs straight through the 4–9 p.m. peak anyway.
The practical difference is between capturing the savings on the days you remember and capturing them on all of them — including the week you are away and the evening you get home late.
Next steps
If you’re in California, our PG&E time-of-use guide covers the same ideas for Northern California, and our SCE guide covers the rest of Southern California. And if your utility uses hourly pricing that changes day to day rather than fixed time-of-use blocks, see how ComEd’s hourly pricing works. For the wider picture on the software that automates this, see what a home energy management system does.
Ready to stop watching the clock? See how Hungry Machines works and sign up now.
Still unsure when to run things? See the cheapest time to run your appliances and whether peak rates apply on weekends.