Imagine a fire breaks out in a metro station or a skyscraper. The lights go out. Smoke fills the hallway. Panic sets in. At this exact moment, two things must happen: The Emergency Lights must turn on to show the exit. The PA System must announce instructions. Both of these systems need electricity. But the building is on fire. The cables powering them are sitting in 900°C fl... https://cometenvirons.com/