3 days ago
Paris blackout caused by heatwave, says network operator
The power cut affected around 1,400 households and buildings on Monday, mostly situated in the oldest part of the city - the Île de la Cité.
Among the buildings affected was the Palais de Justice, which houses the French court of appeal and other courts, and the Paris police HQ.
Grid operator Enedis
said in a statement on Monday morning
: "An incident is underway on the electricity network in the Île de la Cité area of Paris, due to the exceptional episode of high heat over the last few days."
Paris, like much of France, has experienced the first heatwave of the summer in recent days, with
hot weather set to continue until Wednesday
.
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The city of Paris is currently
in the middle of a massive project to replace its underground electricity
cables with heat-resistant ones, after an emergency planning exercise designed to test the city's readiness for the day the temperature hits 50C revealed a major risk of blackouts.
This is not just a Paris-based problem - with power cables melting in heatwaves from Portland to Sicily, the world's 80 million kilometres of power lines are largely unprepared to resist extreme temperatures, scientists have warned.
Work on the Paris cables began in 2024, with the obsolete paper-insulated lead-covered cables (PILC), which are made of oil-impregnated paper encased in a lead sheath, gradually being replaced by a more heat-resilient version.
"We're anticipating the renewal of these cables, which are starting to be affected by heat, to have a very resilient network in Paris," said Olivier Lagnel, deputy regional director for utility firm Enedis.
PILC cables, which were the international standard from the late 19th century until the 1970s, were long considered highly reliable. They were wrapped in layers of oily paper intended to isolate the centre of the cable, which heats up as electrons pass through.
The cables were conceived to resist temperatures up to 90C. But when heat is trapped for days under the asphalt, they can reach 120-130C - ageing faster and eventually risking failure.
Paris's 9,200 kilometres 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 the obsolete cables in French cities by 2050.
"The main problem is that the insulator can dry up, and in that case the cable can be sensitive," said Lagnel.
"The idea is to avoid cuts as much as possible" and to "desensitise the network... as heatwaves come back more and more often, stronger and stronger."
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A searing 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 find ourselves operating in conditions of exceptional climatic emergency," where the temperature of the asphalt on roads reached 50C, it said in a statement at the time.
