The time change, introduced in France in 1976, today raises many questions about its energy relevance. Initially designed to reduce electricity consumption, this device seems to have lost its effectiveness over the years. Let's take a closer look at the issues and real impacts of this practice on our energy consumption.
The evolution of energy savings linked to the time change
The switch to winter time, which takes place each year at the end of October, was supposed to allow substantial electricity savings. On the other hand, the figures show a gradual decrease in these energy gains :
- In 1996: around 1,200 GWh saved
- In 2009: only 440 GWh
- In recent years: around 351 GWh
This decline can be explained in particular by the evolution of the French energy mix. In the 1970s, electricity was mainly produced from fuel oil, a very carbon-intensive and expensive energy source. Today, thanks to development of renewable energies and nuclear powerthe carbon footprint of electricity production has considerably improved.
Furthermore, progress inenergy efficiency lighting systems helped reduce the impact of the time change. LED bulbs, for example, consume much less than their predecessors, making the savings associated with the use of natural light less significant.
Marginal impact on heating and cooling
Contrary to popular belief, the time change only has one negligible effect on consumption linked to heating and air conditioning. These energy expenditure items depend more on the outside temperature than on the time displayed on our watches.
ADEME (Environment and Energy Management Agency) estimated that future savings on these items would be very limited, with only 130 GWh of savings planned by 2030. This figure remains insignificant at the moment. view of France's overall energy needs.
| Year | Estimated energy savings (in GWh) |
|---|---|
| 1996 | 1 200 |
| 2009 | 440 |
| Currently | 351 |
| 2030 (forecast) | 130 |
The time change in the face of renewable energies
One might think that the time change could promote solar energy production by providing an additional hour of sunlight. But this hypothesis turns out to be erroneous for several reasons:
- The maximum production of photovoltaic panels is around noon, when the sun is at its zenith, not at dawn or dusk.
- The solar electricity production naturally decreases in winterwith a drop of approximately three times compared to summer.
- The time change does not affect the actual duration of sunlight, but only our perception of time.
Therefore, the time change has no significant impact on the efficiency or profitability of solar installations. Seasonal variations in production are much greater than the potential effects of time difference.
Towards a questioning of the system
Faced with these findings, the European Parliament recognized in 2017 that the impact of the time change on energy consumption was “marginal”. In 2019, he even voted for its abolition, initially planned for 2021. However, the Covid-19 health crisis postponed this decision, leaving the debate unresolved.
Today, the time change seems less and less relevant from an energy point of view. The savings it allows have become negligible in the face of technological progress and the evolution of our energy mix. In addition, some experts highlight the potentially harmful effects of this practice on our health and our biological rhythm.
As we move toward a more sustainable energy future, it may be time to reconsider this measure from a bygone era. The question is no longer so much whether changing time saves energy, but rather whether it is still justified in our modern society.
