When Is the Cheapest Time to Run Your Appliances? A Per-Utility Guide
On PG&E, SDG&E and SCE, the cheapest hours to run appliances are overnight and midday, and the most expensive window is 4–9 p.m. every day of the week. Move a load of laundry, a dishwasher cycle or an EV charge out of that window and you pay less for exactly the same result.
On SDG&E’s 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.
This guide gives the actual hours and the actual arithmetic, per utility, and then says honestly which appliances are worth bothering about.
The short answer, by utility
| Utility | Cheapest hours | Most expensive | Weekends? |
|---|---|---|---|
| PG&E | Midnight–3 p.m. (EV2-A, E-ELEC) | 4–9 p.m. (5–8 p.m. on E-TOU-D) | Peak applies, except on E-TOU-D |
| SDG&E | Midnight–6 a.m. and 10 a.m.–2 p.m. | 4–9 p.m. | Peak applies every day |
| SCE | Overnight, plus midday super-off-peak on TOU-D-PRIME | 4–9 p.m. (5–8 p.m. on TOU-D-5-8PM) | Peak applies every day |
| ConEd | Overnight only | 8 a.m.–midnight, worst 2–6 p.m. in summer | Check your plan |
| ComEd | Varies daily — published the day before | Usually late afternoon | No fixed window |
| Ameren | Varies daily — published the day before | Usually late afternoon | No fixed window |
Two things in that table surprise people.
Midday is cheap in California. Not just overnight — the middle of the day too. That is a solar effect: so much rooftop and utility-scale generation comes online around noon that daytime power gets cheap, which is why SDG&E’s super-off-peak window explicitly includes 10 a.m. to 2 p.m. A lunchtime dishwasher run can beat a midnight one.
Weekends usually are not exempt. SDG&E and all three SCE plans charge peak rates seven days a week. The Saturday-afternoon laundry habit is one of the more expensive routines a California household can have, and almost nobody knows it.
What each appliance actually costs
Savings depend on how much energy a thing uses. Here is the rough per-cycle picture, priced against SDG&E’s TOU-DR1 spread (about 27¢ super-off-peak, about 58¢ on-peak):
| Appliance | Typical use | Off-peak | At peak | Saved per run |
|---|---|---|---|---|
| EV charge (40 kWh top-up) | 40 kWh | ~$10.80 | ~$23.20 | ~$12.40 |
| Electric water heater (daily) | 8–12 kWh | ~$2.70 | ~$5.80 | ~$3.10 |
| Pool pump (6-hour cycle) | 6–9 kWh | ~$2.00 | ~$4.35 | ~$2.35 |
| Clothes dryer | 2–4 kWh | ~$0.80 | ~$1.75 | ~$0.95 |
| Washer + dryer together | 2–5 kWh | ~$0.95 | ~$2.00 | ~$1.05 |
| Dishwasher (with heated dry) | 1–2 kWh | ~$0.40 | ~$0.85 | ~$0.45 |
| Microwave, kettle, TV | under 0.2 kWh | pennies | pennies | not worth moving |
The ordering matters more than the exact numbers, which vary by plan, model and season. The EV is not just first, it is worth more than everything below it combined. If you do one thing, schedule the car.
Below the car, the pattern is that anything heating water or air is worth moving, and anything else mostly is not. A dishwasher run saves under 50¢. That is real over a year — perhaps $150 across all the small loads — but it is not worth reorganising your evening around. It is worth pressing a delay-start button you already have.
How to actually do it
Use the timers already in your appliances. Most dishwashers and washing machines made in the last decade have a delay-start button, and most people have never used it. Load the dishwasher after dinner, set it for four hours, and the cycle runs at 11 p.m. instead of 7 p.m. That is the entire intervention, it costs nothing, and it captures most of the small-appliance saving.
Schedule the EV in the car or the charger, not by plugging in late. Every modern EV and every smart charger can be told to start at a specific time. Set it once. Plugging in when you get home and letting it charge immediately is the default that costs you the most, because arrival time and cheap time rarely coincide.
Pre-cool instead of shifting the air conditioning. You cannot move cooling to 2 a.m. and still be comfortable at 7 p.m. What you can do is cool the house harder while power is cheap and let it drift up during the peak. A reasonably tight house holds temperature within a couple of degrees over a four-hour evening, which is the difference between running the AC through peak and coasting through it.
Do not bother with the small stuff. Making tea at 3 a.m. saves a fraction of a cent. Time-of-use rewards moving large loads, and treating it as a discipline about every switch in the house is how people burn out on it after a fortnight.
Where this gets harder
Everything above assumes a fixed schedule — the same cheap hours tomorrow as today. That holds on PG&E, SDG&E, SCE and ConEd, where you can genuinely learn the window once.
It does not hold on hourly-priced plans. On ComEd Hourly Pricing and Ameren Power Smart Pricing there is no peak window at all: every hour is priced by the wholesale market and published the afternoon before. The cheapest hour tonight might be 2 a.m. and tomorrow’s might be 11 a.m., depending on wind and demand. A static timer captures some of that and misses the rest.
The same is true of air conditioning even on a fixed rate, because how much pre-cooling pays off depends on tomorrow’s weather. 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 peak anyway.
That is the practical ceiling on doing this by hand. The delay-start button gets you most of the laundry and dishwasher saving forever. Everything beyond it — the right EV start time on a variable rate, the right amount of pre-cooling for tomorrow’s forecast — is a daily decision, and daily decisions are what automation is for. Hungry Machines builds that schedule each night against your utility’s actual rates and your home’s actual thermal behaviour.
Common questions
What is the cheapest time to do laundry?
On a California time-of-use plan, the cheapest time to do laundry is overnight or during the midday super-off-peak window — typically midnight to 6 a.m., or 10 a.m. to 2 p.m. on SDG&E. The most expensive time is 4–9 p.m., when peak rates apply every day of the week including weekends.
A typical wash-and-dry cycle uses 2–5 kWh, so on SDG&E’s TOU-DR1 plan the same laundry costs roughly 60¢ during super-off-peak against about $1.30 at peak. The saving per load is small, but it is entirely free — the clothes come out identical — and it repeats every week. If you have a delay-start button on the machine, using it is the whole intervention.
Is it cheaper to run appliances at night or during the day?
It depends on your utility, and the answer has changed in the last few years. In California both work: overnight is cheap, and so is the middle of the day, because so much rooftop solar is on the grid that midday prices fall. SDG&E’s super-off-peak explicitly covers 10 a.m. to 2 p.m. as well as midnight to 6 a.m.
In New York the answer is overnight only — ConEd’s peak runs 8 a.m. to midnight, so daytime is expensive. On hourly-priced plans such as ComEd Hourly Pricing or Ameren Power Smart Pricing there is no fixed answer, because the cheapest hour is set by the wholesale market and published the afternoon before.
Which appliances are worth shifting?
The ones that are large and genuinely flexible about when they run. EV charging is the clearest case, because the charge has to happen but almost never has to happen right now, and moving 40 kWh across the peak-to-off-peak gap saves more than every other appliance combined. Water heating, laundry, the dishwasher and pool pumps follow, all of which have delay-start timers or scheduling built in. Air conditioning is shiftable in a different way: you pre-cool while power is cheap and let the house coast.
What is not worth shifting is anything small or non-negotiable — lighting, refrigeration, cooking, your router. The rule of thumb is that a load is worth moving if it uses more than about 1 kWh and you do not care exactly when it runs.
Do peak rates apply on weekends?
On most plans, yes. SDG&E prices 4–9 p.m. on-peak every day of the week, and all three SCE residential plans do the same, so Saturday laundry at 6 p.m. costs the same as Tuesday laundry at 6 p.m.
The exceptions are specific: PG&E’s E-TOU-D runs its 5–8 p.m. peak on weekdays only, making weekends entirely off-peak, and on hourly-priced plans there is no peak window at all — weekend afternoons are often cheaper than weekday ones because commercial demand drops. Check your own plan before assuming, because a wrong assumption here costs money every weekend rather than once.
Next steps
Find your own utility’s windows and per-kWh numbers: PG&E, SDG&E, SCE, ConEd, ComEd, Ameren.
For the broader picture of how scheduling every flexible load together works, see what a home energy management system is.