Some of the wildfires that have destroyed thousands of homes in California in the last two years were caused by broken power lines. A utility that supplies electricity to much of Southern California, San Diego Gas and Electric, has developed a system intended to cut off power to a falling power line before it hits the ground, therefore avoiding a possible ignition.
SDG&E’s research found that it takes 1.37 seconds for a broken conductor to hit the ground, for example, if a tree falls into the line or a vehicle hits a power pole. When the line contacts the ground sparks can ignite vegetation. The system is designed to detect a break and shut off the power before the clock hits 1.37 seconds — hopefully, avoiding what could become a dangerous wildfire.
In SDG&E’s video below, they describe the system beginning at 1:40.
If this actually is effective in the real world, it would be a very important method of preventing some wildfires caused by power lines.