California EV Owners on a Time-of-Use Rate
If you're on PG&E, SCE or SDG&E with an EV, the right plan is usually the one built for it: PG&E's EV2-A (about 23¢ off-peak, 54¢ peak), SCE's TOU-D-PRIME, or SDG&E's EV-TOU-5 (about 13¢ super off-peak, 79¢ on-peak, a 6× spread). Charge overnight, not 4–9 p.m., and not only on weekdays: only PG&E's E-TOU-D exempts weekends, and it isn't an EV plan. On EV2-A that's roughly $9 instead of $22 for a 40 kWh charge; on EV-TOU-5 it's roughly $5 instead of $32. Hungry Machines schedules that charge every night, automatically.
Who this is for
- PG&E customers on EV2-A or EV-B (or choosing between them) who charge at home
- SCE customers on TOU-D-PRIME, TOU-D-4-9PM or TOU-D-5-8PM with an EV in the garage
- SDG&E customers on EV-TOU-5, EV-TOU-2 or TOU-DR1 who want the charge timed automatically
- Households comparing plans before or after buying an EV, using a month of their own hourly usage
- Households with solar who want the car to soak up midday production instead of grid power
Not for you if you charge exclusively at public DC fast chargers away from home, none of this applies to power you never buy from your own utility at your own house.
What Hungry Machines does in this situation
You set the target charge percentage, the minimum you'll accept, and the time you need the car ready by. Hungry Machines connects to your charger and your rate plan, PG&E, SCE or SDG&E, static or with your own hourly overrides, and does the rest.
Each night it reads tomorrow's price schedule for your plan and works out the cheapest hours that still hit your charge deadline. If your home also has HVAC, a battery, or a water heater connected, they're scheduled against the same prices at the same time, so the car and the air conditioner never compete for the same cheap hour.
You see the plan before it runs, the hours it picked and the reason, and today's estimated savings on your dashboard or in the Home Assistant panel. Override any slot, or pause the charger's optimization on its own without touching anything else.
The arithmetic
- PG&E EV2-A. about 23¢/kWh off-peak (midnight–3 p.m.) against about 54¢/kWh peak (4–9 p.m.). A 40 kWh top-up runs roughly $9 instead of $22.
- SCE TOU-D-4-9PM. about 37¢/kWh off-peak against about 60¢/kWh on-peak, roughly 1.6× for the same energy. TOU-D-PRIME trades a fixed monthly charge for cheaper super off-peak energy on top of that spread.
- SDG&E EV-TOU-5. about 13¢/kWh super off-peak against about 79¢/kWh on-peak, roughly 6×. The same 40 kWh top-up runs roughly $5 instead of $32.
- Across every utility. the EV is worth more than every other flexible appliance in the house combined, because nothing else moves 40 kWh across a single decision.
These are the published per-kWh rates run through plain arithmetic, not measured results from Hungry Machines customers. Your own saving depends on your plan, your charger's power, and how much of your charging already happens overnight.
How to set it up
If you already run Home Assistant, the Home Assistant integration reads the charger entity you already have, install it through HACS, sign in, and map the charger when you add it as an appliance. No Home Assistant instance yet? The Home Hub is a plug-in box that coordinates the charger alongside your HVAC, water heater and battery on its own hardware. Either route runs the free tier on one device with no payment method required; see pricing for what Premium adds.
Read the full guides
- PG&E Time-of-Use Rates: A Plain-English Guide to Saving
- SCE Time-of-Use Rates: A Plain-English Guide to Saving
- SDG&E Time-of-Use Rates: How to Actually Save With Them
- When Is the Cheapest Time to Run Your Appliances? A Per-Utility Guide
- Do Peak Electricity Rates Apply on Weekends? PG&E, SDG&E, SCE and ConEd
Frequently asked questions
Which California utility plan is best for an EV?
It depends on your utility and your total usage, but each has a purpose-built answer. On PG&E, EV2-A is the standard pick, its midnight-3 p.m. off-peak rate is among the lowest PG&E offers, which rewards charging overnight; the older EV-B has a wider 2-9 p.m. peak, so keeping the car out of that window matters even more. On SCE, TOU-D-PRIME usually wins for an all-electric home (EV plus heat pump, maybe a battery), trading a fixed monthly charge for cheap super off-peak energy. On SDG&E, EV-TOU-5 has the widest daily swing of any plan in this guide, about 13¢ to 79¢/kWh. None of the three utilities lets you compare across each other's plans directly, so the honest step is pulling a month of your own hourly usage before switching.
Does the cheap EV charging window apply on weekends?
Mostly yes, which surprises many people. SDG&E's on-peak window and all three SCE plans run their 4-9 p.m. peak seven days a week, with no Saturday or Sunday exemption. PG&E's EV2-A and EV-B do the same. The one weekend exemption in this guide is PG&E's E-TOU-D, but that is a general household plan with a 5-8 p.m. weekday-only peak, not one of the EV-specific plans, so if you're on EV2-A or EV-B, a Saturday night charge costs exactly what a Tuesday night charge does, and the overnight window is your cheapest option every day of the week.
Do I need solar to benefit from scheduled charging?
No. The saving comes from when you draw power from the grid, not from what's on your roof, on PG&E's EV2-A the off-peak-to-peak gap is roughly 23¢ against 54¢ with or without panels. Solar does change the shape of the problem: it tends to cover midday load already, so the remaining opportunity concentrates in the evening peak and overnight hours, exactly where a scheduled charge does its work. Under NEM 3.0, self-consuming your own production usually beats selling it at the export rate, which makes a scheduled overnight or midday charge more valuable to a solar household, not less.
About Hungry Machines
Outsmart your electric bill - Hungry Machines Energy provides an energy management system that shifts HVAC, EV charging, home batteries, and other electric loads to cheaper hours for homes and buildings with solar power or variable electricity rates.