Most households focus on thermostat settings and insulation hacks, but often overlook a crucial detail — when the heating is turned on or off. Energy experts are now pointing out that the clock on your wall can affect your bill just as much as your thermostat.
The Critical Role of Heating Timings
In countries like France, where this new guidance originates, winter weekdays see a massive surge in energy use. Mornings and evenings are especially demanding, as millions of people simultaneously switch on lights, appliances, and heating systems. This synchronized behavior leads to sharp increases in electricity prices and puts pressure on the power grid.
Peak Hours and Their Impact
According to Hello Watt, heating during peak hours — especially 7:00–9:00 AM and 18:00–20:00 PM — not only costs more but also contributes to the use of higher-emission power sources. During these times, utilities often pay premium rates for electricity, passing those costs down to users.
Recommended Heating Windows
Experts suggest shifting heating patterns slightly to reduce costs and strain on the grid. Hello Watt highlights two ideal time slots:
- Morning: 6:30 to 7:30 — Just before the national surge begins.
- Evening: 17:30 to 21:00 — Maintain steady warmth rather than sudden high heat.
This approach allows your home to store warmth early and maintain comfort without forcing your system into overdrive during high-demand periods.
How to Implement Smart Heating
Modern heating systems and programmable thermostats make it easy to align with smarter energy hours. The trick is to preheat and maintain, rather than heat reactively at peak times.
Thermostat Programming Tips
- Morning setting: 6:30 to 7:30, aiming to reach desired temperature by 7:30.
- Evening setting: Begin at 17:30 and keep it moderate until 21:00.
- Avoid quick jumps: Sudden increases, like from 16°C to 22°C, consume more power.
- Don’t overheat empty spaces: Reduce heating in unused rooms like corridors or guest bedrooms.
Heating gradually and consistently saves energy and keeps systems running more efficiently.
Room-Wise Temperature Recommendations
Proper timing is only part of the equation. Target temperatures by room type also influence energy use. European agencies often suggest:
| Room Type | Recommended Temperature |
|---|---|
| Living Room | 19°C to 20°C |
| Bedrooms | 16°C to 17°C |
| Kitchen | 17°C to 18°C |
| Bathroom (in use) | 21°C to 22°C |
| Unused Spaces | 14°C to 16°C |
Even lowering the thermostat by 1°C can lead to meaningful savings when applied consistently.
Wider Benefits for the Grid and Environment
Shifting heating times may seem minor, but when done at scale, it reduces the need for polluting backup power sources. During national peak hours, power plants often rely on the dirtiest and costliest energy to meet demand. Avoiding this helps with climate goals and supports more sustainable grid operations.
Different Heating Systems, Different Responses
Not all systems behave the same when schedules change. Here’s how different setups respond:
- Electric Radiators: Heat up fast. Great for timed heating windows.
- Heat Pumps: Best when running at low power continuously. Preheating helps maintain comfort during peaks.
- Storage Heaters: Charge at night using off-peak tariffs. Daytime usage should align with their stored warmth.
Whether you’re on a time-of-use tariff or a flat rate, timing still affects your bill due to how suppliers average costs.
Understanding Peak Demand and Load Shifting
Peak demand is when a country’s total electricity usage is at its highest — typically around 19:00 on cold evenings. Load shifting means moving energy use, like heating or appliance operation, to quieter times to relieve stress on the grid.
Example: Smart Heating in a Typical Flat
Consider a home using electric radiators. The residents wake at 7:00, leave at 8:30, and return at 18:00. Normally, they might heat from 7:00 and again at 18:00. But under Hello Watt’s method:
- Morning heating starts at 6:30 and reaches target temperature by 7:00, tapering off during the 7:00–9:00 peak.
- Evening heating starts at 17:30, providing comfort ahead of the 19:00 demand spike.
If they also reduce the average temperature from 21°C to 19.5°C and avoid heating spare rooms, hundreds of kilowatt-hours can be saved over a winter.
Smart Habits That Add Up
Small, consistent changes — starting heat 30 minutes earlier or lowering temperatures by 1°C — can lead to significant results without discomfort. For homes facing rising costs, this offers a balanced approach between savings and warmth.
