“Over the last five years, Southern California Edison—the utility that serves Los Angeles—has been testing a way to prevent downed power lines from starting fires. The technology, a kind of power diverter called Rapid Earth Fault Current Limiter (REFCL), detects a current surge caused by power line fault, such as a line struck by a tree, and instantaneously collapses the voltage before a fire can ignite.

According to SoCal Edison’s testing results, posted in December 2022, REFCLs work. In all four testing locations, which the utility conducted among the scrub that grows in the mountains and high desert regions around L.A., the power diverters made the system release 99.99 percent less energy from ground faults compared to Edison’s typical designs.”

From IEEE Spectrum.