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The environmental case for keeping the clocks on summer time – all the time

Early to bed and early to rise makes a man healthy, wealthy and … also energy efficient, as it turns out.

After 1am on Sunday night here in Oxford the time suddenly jumped forward to 2am – the UK is now officially on “British Summer Time”, where it will remain for the next seven months. The rest of Europe also put its clocks forward at the same moment, while the US and Canada moved to summer time earlier in March. Collectively, this is known as daylight saving time.

But what if all these countries kept to summer time throughout the winter? About a decade ago researchers at the University of Cambridge made a strong case that, in the UK at least, it would have a range of positive effects. Twelve months of summer time could reduce road deaths and crime, boost business and trade and also reduce energy consumption at peak times by up to 8%. All of this is possible because our most active periods would be better aligned with daylight hours.

Shifting the timing of electricity use has gone up the academic agenda for another reason. Flexible demand has the potential to save billions in the integration of renewables, such as wind and solar.

The logic is simple: the highest energy demand occurs in winter around 5.30pm. This is when people come home and many businesses are still open. It’s also when it is cold and dark and we need extra energy for heat and light. Yet, output from low-carbon solar power is pretty much guaranteed to be zero.

5pm in December – or 6pm? mvtstockshot / shutterstock

If British Summer Time was continued through the winter, the peak-demand problem would be reduced. Everyone would get up an hour earlier, work earlier and come home earlier, often when it is still light. Activity would still peak at around 5.30pm human time, but that same time would be earlier relative to sunset.

Given that lighting alone may be responsible for 20% of peak demand in the UK, there is lots of scope for saving energy. One review found that using energy at different times could lead to peak reductions of up to 8%.

In lighter evenings there might even still be some solar power available to further reduce the net demand for fossil fuels. The savings in the evening would exceed any potential increase in the mornings.

So why don’t we talk more about how daylight saving hours could help the effort to decarbonise? One reason is political economy – while getting up an hour earlier makes sense to an expert in energy policy or road safety, it won’t necessarily be popular with the public (not to mention Scottish farmers or teenage children).

This is the same problem that affects many other potentially very sensible energy saving measures: as soon as there is even a remote chance of inconveniencing people, it is likely not to see the light of day. This is part of the reason why energy policy making is dominated by measures to boost supply such as new nuclear plants, fracking, or support for renewables. Tampering with the demand side requires a lot of political courage.

However, we may be able to put a more positive spin on it. Why should changing what we call “7am” to “8am” make such a difference anyway? After all, it is just a relabelling exercise.

It is fascinating how an entire society re-synchronises its activities based on a change of the clock hands. Yet if people stuck to their own rhythm they could avoid the worst rush hours and even get home in daylight during the winter.

Of course it is not that simple. Our daily rhythms are strongly reinforced by traditional conventions, such as working hours, schooling hours and shop opening hours. It began in the 19th century with factories using time to synchronise their workforce into shifts. With the arrival of the railways, clocks across the country were synchronised and millions of people began to operate to the same rhythm – not their natural rhythm, but the clock rhythm.

There are some obvious benefits to having a workforce in the same place at the same time. However, when looking at the system as a whole, synchronisation brings with it some serious challenges, most notably peak demand constraints.

It may therefore not be all that helpful to shift everyone’s day by one hour with a nationally synchronised clock change. Allowing for some more diversity to develop instead could be advantageous. More flexible working hours could reduce and spread peaks. This could even be encouraged regionally, given that Cornwall, on England’s south coast, faces very different daylight conditions than, say, north Scotland.

You don’t need to wait for the government either. Next autumn, when the clocks go back, be a rebel and just go to bed one hour earlier – that is, don’t change anything. You’ll not only reduce energy demand, but also help to diversify it.

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