It works like a normal light bulb even during power outages. The Smart Charge bulb with proprietary patent pending Grid & Switch Sensor technology, senses a power outage, recognizes the ON/OFF position of your light switch and allows control of the light even with no utility/grid power. During a power outage the lights go out and the lamps in your house are useless. Smart Charge bulbs keep you from ever having to worry about being in the dark again. Your lights will continue to operate and even better you can control them with your wall and lamp switches.