Do clock changes save energy? Experts say the difference is negligible

 Several studies in Europe and the US show DST has very little effect on energy conservation.
Several studies in Europe and the US show DST has very little effect on energy conservation. Copyright Luke Chesser
Copyright Luke Chesser
By Rebecca Ann HughesAndreas Rogal
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Several studies in Europe and the US show DST has very little effect on energy conservation.


On 31 March, people across Europe will be moving their clocks forward one hour, but it could be one of the last times this happens.

The efforts to abolish Daylight Savings Time (DST) could be revived in the EU if a petition by experts is successful.

They hope the issue will be taken up during the European election campaign, putting pressure on the Member States to put the issue - recommended by the Commission and supported by the ParlIament - back on the agenda.

In 2018, the European Commission officially proposed the abolition of the twice-a-year clock changes and Parliament supported that proposal in a resolution in March 2019. It came after a public consultation by the Commission showed strong support from 4.6 million EU citizens for scrapping it.

The changes were meant to come in by 2021 but have since been stuck with the EU's co-legislator, the Council of the European Union, representing the 27 Member States.

The Member States are divided over the practical implementation of the change.

As the discussion resurfaces, one of the biggest questions yet to be conclusively answered is whether DST actually reduces energy consumption.

Several studies have found that DST’s impact on the environment is negligible, or even negative. So is time up for seasonal clock changes?

Why was Daylight Saving Time introduced in Europe?

In the UK and Germany, DST was introduced to conserve coal in World War I. It was abolished when the war ended but returned during the 1980s when the necessity to save resources returned, driven by the global oil crisis.

Since 2002, all countries in the European Union - except for Iceland - have had to adjust their clocks on the last Sunday of March and October.

Does Daylight Savings Time reduce energy consumption?

Several studies in Europe and the US show DST has very little effect on energy conservation.

In Italy, the Italian Society of Environmental Medicine calculated that even postponing the clock change from the end of October to the end of November would save the country €70 million in fuel bills.

A study by researchers at Charles University in Prague used hourly data from 2010 to 2017 to find that DST in Slovakia resulted in estimated energy savings equal to just 0.8 per cent of annual electricity consumption.

In the US, a study conducted by the Department of Transportation in 1975 showed that Daylight Savings cut around 1 per cent of the country’s energy usage.

This insignificant saving might, in part, be because many people in the US get out of bed before 7am. Much of the energy saved by not having the lights on in the evening was offset by having them on in the morning.

A 1993 publication on fuel (gas, coal) consumption in France and Belgium observed an increase in fuel consumption with DST due to extra driving. This was corroborated by studies on pollutant dispersion.

Instead, natural time zones as close as possible to solar time likely align daily light and temperature curves better with our schedules.

This could lead to energy savings on early morning industrial and other lighting, early morning heating during the colder months as people leave for work an hour later and less air conditioning needed in the car on the commute after work and in the evening at home.


Will Europe stop changing its clocks?

Last year, experts asked the Council of the European Union to add the topic of abolishing clock changes to its agenda.

With the proposal to end clock change not yet implemented, those in favour of abolition hope the issue will now be addressed at June’s EU Parliament elections.

The Time Use Initiative has launched an EU Manifesto on Time Policies including twelve necessary changes Europe needs to make to assure the “right to time” to all the Europeans.

“The EU must react to the negative impact of misaligned clocks by pushing to implement permanent time zones as close as possible to solar time (natural time) in Europe,” the manifesto reads.

“Misaligned clocks that make schedules start earlier than the natural day-night cycle increase sleep deprivation and cause negative effects on human health, economy, and safety. The EU has the power to change this.”


The article has been updated to clarify the EU's institions' approach to DST .

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