Europe’s streets go dark to save energy

Pushed by a looming energy crisis, cities across Europe are switching off the lights.

While Spain has made such measures mandatory, ordering shops to turn their lights off at night, in other places local authorities are voluntarily hitting the switch, arguing it’s a good time to trial light-saving measures.

Berlin is switching off the spotlights illuminating 200 of its historic buildings and monuments, and a number of towns and cities in Austria, Germany and Italy have reduced street lighting or turned off commercial signs.

In France, 14 communes in the Val d’Oise department north of Paris are trialing measures to fully switch off public lighting at night. Local authorities estimate shutting off street lights for three-and-a-half hours every night will help curb energy consumption by about a quarter.

“The energy [price] boom made us take the step and try this experiment,” Yannick Boëdec, mayor of the Cormeilles-en-Parisis commune, told BFMTV in June.

The towns join some 12,000 communes in France that already either fully or partially switch off public lighting at night.

These measures are backed by light pollution activists and scientists, who argue that excessive artificial light wreaks havoc on human health and the environment.

Turning off the lights is the “easiest” measure to take as it “costs almost nothing and … immediately pays off in euros, in kilowatt hours saved and in reduction of light pollution,” said Anne-Marie Ducroux, the spokesperson of ANPCEN, a French association fighting light pollution.

The plans are part of the bloc’s response to the energy crunch, but some worry that turning off street lights will make cities less safe.

“Public lighting contributes to public safety,” said a business manager living in Taverny, one of the communes participating in the experiment, arguing that the focus should be on limiting other types of light, for example from shop windows.

Safety debates

For the French communes in Val d’Oise, the main motivation for switching off street lights between 1:15 a.m. and 4:45 a.m. is to keep public spending in check as energy prices soar.

Boëdec said his commune spent €2 million on public lighting in 2021; that could jump to €2.8 million this year if no action is taken.

But the communes are keen to highlight that the experiment will also tamp down on light pollution. More darkness will help “respect the rhythm of day and night, allowing species to regenerate,” said Carole Faidherbe, the first deputy mayor of Taverny.

Scientists have long warned that light pollution disrupts biodiversity and human health. Excessive use of artificial light at night is linked to insect population decline — with potentially dire impacts on food chains — and changes in the migratory routes of birds. It’s also been found to contribute to a host of health issues in people, including cancer.

Still, not everyone is convinced that it makes sense to shut off the lights to help nature.

“Cities are increasingly dense and concrete. Trees are regularly cut down for real estate projects, in schoolyards or colleges, to build cycling lanes … so, putting forward the protection of animals to justify this decision is not credible,” said a resident of Eaubonne, a commune participating in the scheme. She added that she’d like to “know the statistics of the problems encountered during the time the lights are off.”

Most of the concerns raised by locals revolve around safety, according to Faidherbe, the official from Taverny, though she also stressed that the backlash wasn’t as strong as she’d expected.

The measures were designed with safety in mind, she said. The time window accounts for the arrival of the last train of the night and the departure of the first train of the morning and can be adjusted on national holidays, when streets are busier than usual at night. She added that video surveillance continues to operate even when the lights are off.

Faidherbe and ANPCEN’s Ducroux also pointed to data from other parts of France that show no link between shutting off public lights and an uptick in crime.

The city of Mouy in northern France, for example, recorded a slight decline in robberies and damages after it switched off street lighting in 2015.

“Many fear that safety decreases, but there are multiple studies that show that safety does not decrease with less light or that more light does not contribute to more safety,” said Reinhard Klenke, a biologist at the Helmholtz Centre for Environmental Research in Germany.

But a perceived lack of safety can have a major impact — particularly on women, who could limit their movements as a result, according to Inés Sánchez de Madariaga, UNESCO chair on gender in science, technology and innovation.  

Being able to see one’s surroundings is key to feeling safe, she said. “When women perceive a risk of sexual assault, a risk of insecurity, they stop going places.”