New summer off-peak hours: the best time to run your air conditioning changes in 2026
The Proclimo Team
13 Jul 2026 - 05 min read
For forty years the rule was simple: electricity was cheaper at night. That rule is changing. Since 1 November 2025, Enedis has been rolling out the biggest reform of off-peak hours since they were introduced in the 1970s, and the second phase — the one that brings in seasonality — arrives in the second half of 2026. In practice: in summer, up to 3 off-peak hours shift into the middle of the day, between 11am and 5pm. In other words, precisely when your air conditioning is running.
For a household with reversible air conditioning or a heat pump, this is not an administrative footnote: it is a chance to cut your summer bill without sacrificing any comfort. But you need to understand what is changing.
Why off-peak hours are moving
Off-peak hours were never designed for your comfort, but for the grid's: the idea is to encourage households to consume when production is plentiful, and to ease off when the system is under strain. In the 1970s, that abundance happened at night — nuclear plants running continuously.
Today the picture has changed. The rapid growth of solar photovoltaics means that at midday in summer, France produces abundant, cheap electricity. Conversely, the strain has shifted to early morning (7-11am) and the evening (5-11pm). France's energy regulator (CRE) therefore called for the calendar to be redesigned to align off-peak hours with actual production.
The basic principle does not change: you still get 8 off-peak hours a day. What changes is how they are spread:
| Old system | New system (summer) | |
|---|---|---|
| Night | 8 off-peak hours, often 10pm-6am | At least 5 consecutive hours (often 11pm-7am) |
| Daytime | None | 2 to 3 off-peak hours between 11am and 5pm |
| Seasonality | None | Yes: summer slots (1 April – 31 October) differ from winter |
| Slots avoided | — | 7-11am and 5-11pm (consumption peaks) |
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The rollout is gradual and runs until the end of 2027. Around 1.7 million customers were affected from November 2025; a further 9.3 million households switch over from the second half of 2026. Your supplier must notify you at least one month before your time slots change. Do not change your habits until you receive that notification: your existing off-peak hours remain valid until then.
What it means for your air conditioning
This is where the reform gets interesting. Reversible air conditioning — technically an air-to-air heat pump — draws most of its electricity in the afternoon, when the heat peaks. Until now those hours were billed at the full peak rate. From now on, some of them will fall into off-peak hours.
Three uses benefit directly:
- Pre-cooling. Rather than switching the air conditioning on at 6pm as you walk into an overheated home, you run it between 11am and 5pm — at the reduced rate — to hold the temperature. A home you prevent from heating up always costs less than a home you have to cool down in a hurry come evening.
- Building inertia. Walls, floors and partitions store coolness. Cooling moderately during the afternoon off-peak hours "charges" that inertia, letting you ease off in the early evening when the rate goes back up.
- Solar self-consumption. If you have panels, the new off-peak hours coincide with your production peak. The two logics reinforce each other.
Three habits to make the most of it
1. Check your actual slots. Your off-peak hours appear on your bill and in your online account. They vary from one neighbourhood to another: there is no single national timetable. Do not rely on "typical" hours you read elsewhere.
2. Programme it, don't just react. Almost all recent reversible air conditioners offer time-based scheduling, often controlled from an app. That is the tool that turns the reform into real savings. Set the unit to start during your new off-peak slots rather than reaching for the remote each time.
3. Aim for the right temperature. No tariff optimisation makes up for a badly set thermostat. The recommended gap remains 5 to 7°C below the outdoor temperature, and every degree saved represents roughly 7% less consumption. We cover these settings in our guide on setting your air conditioning during a heatwave.
warning
Beware the perverse effect: daytime off-peak hours are not an invitation to use more air conditioning. The saving comes from shifting consumption, not increasing it. Before switching the unit on, think about passive measures — shutters closed during the hottest hours, night ventilation, and a properly maintained ventilation system — which reduce overheating without using a single kilowatt-hour.
A well-maintained system, or nothing
Optimising your tariff on a clogged unit is like negotiating the fuel price while driving with a badly tuned engine. An air conditioner with blocked filters or an incorrect refrigerant charge can lose up to 30% of its efficiency: you then pay for more hours — off-peak or not — for the same result.
This matters all the more because maintenance of these systems is required by law, with a mandatory periodic inspection above certain power thresholds. An annual service remains the single best saving lever available — well ahead of tariff optimisation. We break down its real cost in our article on the price of an air conditioning service in 2026.
Finally, if you are considering new equipment, the arrival of afternoon off-peak hours strengthens the case for programmable, connected models. Our guide on choosing the right air conditioner in 2026 reviews the criteria to prioritise, and the reduced VAT on reversible air conditioning can significantly lower the installation bill.
Frequently asked questions
Do the new off-peak hours apply to everyone? No, only to customers on a Peak / Off-Peak tariff option — around 14.5 million households. If you are on the Base option, you have no time slots and nothing changes for you.
Will I lose my night-time off-peak hours? No. The new calendar guarantees at least 5 consecutive off-peak hours at night. Only 2 to 3 hours move to the afternoon, and only during the summer period (1 April to 31 October).
Do I need to do anything? Nothing at all. The change is automatic and your supplier informs you at least a month in advance. If your air conditioning or water heater is driven by a day/night contactor wired to the meter, the switch happens by itself.
Will my air conditioning really cost less? It will cost less for the same usage, if you shift its operation into the new off-peak slots. Without reprogramming, you will see no difference: it is the act of scheduling that creates the saving.
And in winter, for a heat pump? In winter, off-peak hours remain mainly at night. An air-to-water heat pump therefore keeps the classic pattern, with no notable change. The wider regulatory context is set out in our article on the 2026 electrification plan.
Does this also apply to business premises? Yes, the same tariff logic applies, and the financial stakes there are often far higher. See our article on air conditioning for offices and business premises.
Turn your system into a real saving lever
New off-peak hours, scheduling, settings, maintenance: each of these levers is worth a few percent. Together, they make a clear difference to your summer bill.
Our technicians can check the condition and settings of your system and help you make the most of your new time slots. Discover our air conditioning maintenance for private homes, our installation services, or contact Proclimo for an assessment and a clear quote.
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