When the grid goes south, California can’t rely on four-hour backups. Caltrans just showed us why batteries alone don’t cut it.
Back in June 2024, the California Department of Transportation (Caltrans) wrapped up a field and lab trial of the HyMax Hydrogen Fuel Cell Backup Power System from Western Systems. Set up at their main site on Lower Sacramento Road, the unit kept traffic lights running for a whopping 5 days and 18 hours straight under load—compared to the usual four-hour stretch with standard batteries. Today, over 50 HyMax units are scattered across rural roads, school zones, and key evacuation routes, all certified zero-emission by the California Air Resource Board.
What It Means: Longer runtimes at intersections mean safer roads during wildfires, big storms, and those surprise PSPS outages—all while sticking to California’s climate goals.
Historical Context
Until now, most traffic signals leaned on lead-acid…
