Infrastructure remembers the climate in which it was built
Electrical equipment installed decades ago is physically unable to handle modern heatwaves, as copper wires and oil-filled transformers reach their melting points in a warming world.
Modern power grids are essentially time capsules of the mid-20th century. Many of the transformers and high-voltage transmission lines powering our homes today were installed during the 1960s and 70s, an era when engineering margins were based on much cooler historical averages. These components were designed to shed heat into the surrounding air to stay functional, but when ambient temperatures exceed their specific design thresholds, the physical materials begin to fail. Copper wires expand and sag toward the ground, while the cooling oil inside massive transformers can degrade or even boil, risking catastrophic equipment fires.