France's City of Light switches to climate-resistant power cables October 12, 2024

Paris is removing a network of obsolete power cables with new ones that are more resistant to extreme heat (STRINGER) (STRINGER/AFP/AFP)

By AFP - Agence France Presse

France's City of Light switches to climate-resistant power cables

Nathalie ALONSO

To keep the City of Light sparkling, Paris is modernizing its underground power cables, which are vulnerable to damage during heat waves and date back 60 years.

With power cables melting from Portland to Sicily, scientists have warned that the world's 80 million kilometers (50 million miles) of power lines are not prepared to withstand extreme temperatures.

In the coming months, the French capital will replace its obsolete lead-insulated paper-clad cables (PILC), made of oil-impregnated paper wrapped in a lead sheath.

“We are anticipating the renewal of these cables, which are starting to be affected by the heat, to have a very resilient network in Paris,” said Olivier Lagnel, deputy regional director of the utility company Enedis.

Nearby, workers in orange vests were working in a trench near Montparnasse train station to replace the medium-voltage PILCs installed in 1965 with modern plastic cables.

State-owned Enedis says Paris is not alone: its counterparts in Chicago, London, Shanghai, Hong Kong, Osaka, Tokyo, Singapore, and Sydney are also planning to upgrade their cables.

- Climate emergency

Problems have increased in recent years.

Cables insulated with paper during a 2003 heatwave in France showed weaknesses with “an incident rate multiplied by eight across the entire underground medium-voltage network,” according to a March 2024 report by the French Court of Auditors.

Overhead streetcar cables melted in Portland in 2021 during record-breaking temperatures in the northwestern US state of Oregon.

A scorching heatwave in July 2023 left hundreds of thousands of Sicilians without electricity and water for days.

Heat damage to underground cables was to blame, said supplier e-distribuzione, the distribution arm of energy giant Enel.

“We are operating in conditions of exceptional climatic emergency,” where the temperature of the asphalt on the roads reached 50 degrees Celsius (122 degrees Fahrenheit), the company said in a statement at the time.

A 2021 study led by Alessandro Bosisio, an assistant professor at the University of Pavia in Italy, found that “an abnormal increase in failures in underground medium-voltage cable joints has been recorded, especially during the summer” around the world in recent years.

Climate scientists say that the period you are living through now is probably the warmest the Earth has seen in the last 100,000 years, at the start of the last Ice Age.

- Avoid cuts - You can avoid cuts.

PILC cables, which were the international standard from the late 19th century until the 1970s, were considered highly reliable for a long time.

They were wrapped in layers of greasy paper in order to insulate the center of the cable, which heats up as electrons pass through.

The cables were designed to withstand temperatures of up to 90C (194F). But when the heat is trapped for days under the asphalt, they can reach 120-130C (248-266F) - aging more quickly and eventually risking failure.

Paris' 9,200 kilometers of low- and medium-voltage power cables are entirely buried underground - to save space and protect them from the wind, Lagnel said.

Enedis plans to phase out obsolete cables in French cities by 2050.

“The main problem is that the insulator can dry out, in which case the cable can become sensitive,” said Lagnel.

“The idea is to avoid cuts as much as possible” and 'desensitize the network? Since the heatwaves are coming back more and more often, stronger and stronger.

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