The best smart thermostat for PG&E time-of-use rates is the one that reliably moves heating and cooling out of 4-9 p.m. On E-TOU-C, that window is peak every day, including weekends. Summer peak is $0.52240 per kWh versus $0.39940 off-peak. A thermostat that pre-cools before 4 p.m. and coasts through peak attacks the hours that cost the most.

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Key facts

Rates below are PG&E bundled Total Energy Rates from Electric Schedule E-TOU-C, effective March 1, 2026. Source: E-TOU-C tariff PDF.

Why HVAC is the load worth shifting

Most household loads are hard to move. You cook dinner when you eat dinner. The TV runs when people watch it. Air conditioning is different: a house stores coolness (and heat) for a while. You can run the system harder at 2 p.m., when it is off-peak, and let the house drift slowly through 4-9 p.m.

That matters most on hot summer afternoons. That is when central AC works hardest. It is also when E-TOU-C charges its highest rate. Every kWh the compressor uses at 5 p.m. instead of 3 p.m. costs $0.12300 more on the summer bundled rate.

This article does not invent a savings number. How much you save depends on your home's insulation, your AC size, your climate territory, and how much comfort you are willing to trade. A well-sealed house in a mild coastal zone may barely need AC at peak. A stucco ranch in the Central Valley may run it all evening.

How pre-cooling works

Pre-cooling is a schedule, not a gadget. The thermostat just makes it automatic.

  1. Before peak (roughly 1-4 p.m.): cool the house a few degrees below your normal setting while power is off-peak.
  2. At 4 p.m.: raise the setpoint a few degrees. The house is already cool, so the AC stays off or cycles lightly while indoor temperature drifts up.
  3. At 9 p.m.: return to your normal setting. Any recovery cooling now happens at off-peak rates.

A few practical rules:

Pre-heating in winter

The same logic runs in reverse for electric heat (a heat pump or electric furnace): warm the house before 4 p.m., lower the setpoint during peak, recover after 9 p.m.

Be realistic about the payoff. The winter E-TOU-C spread is only $0.03000/kWh, so shifting saves much less than in summer. And winter evenings are cold, so the house loses heat faster. Gas heating does not touch your electric TOU rate at all, apart from the blower fan. For many PG&E homes, winter pre-heating is a comfort tweak, not a bill strategy.

If you heat with a heat pump, see PG&E Rate Plans Compared. Heat pump customers may qualify for other plans whose rates and windows differ.

What to look for in a TOU thermostat

Any thermostat with a schedule can pre-cool. The ones worth paying for do it with less babysitting:

Our picks

Best overall: ecobee Smart Thermostat Premium

The ecobee Smart Thermostat Premium is our top pick for E-TOU-C households. It ships with a SmartSensor for a second room, so the system cools the room you are in, not just the hallway. Scheduling is flexible enough to build a clean pre-cool / peak / recover pattern. The included Power Extender Kit helps in homes without a C-wire.

ecobee also uses a built-in occupancy sensor to adjust when the house is empty. That stacks well with TOU: an empty house during 4-9 p.m. on a weekday can ride a higher setpoint with no comfort cost.

Best for: homes with uneven temperatures between rooms, and anyone who wants fine control over the schedule.

Best learning thermostat: Google Nest Learning Thermostat (4th gen)

The Google Nest Learning Thermostat (4th gen) includes a Nest Temperature Sensor and builds a schedule from how you use it. Smart Schedule suggests changes and asks you to approve them in the Google Home app, so it will not quietly undo your peak setpoints. Google says the 4th gen works with most 24V systems and usually does not need a C-wire.

The learning approach suits people who will not sit down and program a schedule. The tradeoff: if you want a strict pre-cool window, set it deliberately rather than relying on learning alone. A learning thermostat optimizes for your habits. It does not know your rate plan unless you tell it.

Best for: Google Home households and people who want a thermostat that mostly runs itself.

Budget pick: Amazon Smart Thermostat

The Amazon Smart Thermostat is ENERGY STAR certified and supports schedules with up to seven time periods per day of the week. That is more than enough for a pre-cool / peak / evening pattern. It runs through the Alexa app.

Know its limits. It requires a C-wire or a separately sold power adapter. It works on 2.4 GHz Wi-Fi only. It does not include a remote room sensor. If your thermostat sits in a hallway far from the living room, comfort during peak may be harder to judge.

Best for: a straightforward upgrade from a manual or basic programmable thermostat, in a home that already has a C-wire.

A sample E-TOU-C summer schedule

Use this as a starting point, then tune it to your home. Replace "normal" with your own preferred temperature.

Time Setpoint Why
12 a.m.-1 p.m. Normal (or warmer when away) Off-peak; no need to pre-cool yet
1-4 p.m. 2-3 degrees below normal Pre-cool at off-peak rates
4-9 p.m. 2-3 degrees above normal Peak; let the house coast
9 p.m.-12 a.m. Normal Off-peak recovery

Then check the result on a real bill. Your PG&E bill and online usage data show kWh by time-of-use period. If peak kWh did not fall, the schedule is not doing its job.

CCA customers

The rates above are PG&E bundled rates. If a community choice aggregator (MCE, PCE, EBCE, SJCE and others) supplies your generation, your generation charges follow the CCA's rate sheet. PG&E still bills delivery on the E-TOU-C schedule. The 4-9 p.m. peak window is the same idea, but your exact per-kWh spread will differ. See Community Choice Aggregation Explained.

Will a thermostat make E-TOU-C the right plan?

Not on its own. A thermostat helps you use the plan you are on. Whether E-TOU-C is the right plan depends on your whole usage pattern. For the full plan menu, read PG&E Time-of-Use Rates Explained.

Before you buy hardware, check what you are actually paying for. Upload your PG&E bill to My Big Bill for a free audit. It compares your usage against PG&E's published rate plans and shows how much of your bill lands in peak. It will not invent a savings figure your bill does not support.

Frequently asked questions

What are PG&E's E-TOU-C peak hours?

4-9 p.m. every day, including weekends and holidays. All other hours are off-peak. Source: PG&E Electric Schedule E-TOU-C.

Does pre-cooling actually save money?

It can, when it moves AC runtime from peak to off-peak without adding much total runtime. The summer bundled spread is $0.12300/kWh. Results depend on your home's insulation and how far you let the temperature drift during peak. Compare peak kWh on bills before and after.

Do I need a smart thermostat to pre-cool?

No. A basic programmable thermostat with at least three daily periods can run the same schedule. Smart thermostats add remote sensors, app control, and occupancy detection, which make the schedule easier to live with.

Do I need a C-wire?

It depends on the model. The Amazon Smart Thermostat requires one or an adapter. The ecobee Premium includes a Power Extender Kit. Google says the Nest Learning Thermostat (4th gen) does not need one in most homes. Use each manufacturer's compatibility checker first.

Should I pre-heat in winter?

Only if you heat with electricity, and expect a smaller payoff. The winter E-TOU-C spread is $0.03000/kWh, a fraction of the summer spread.

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