Skylights only provide illumination during the day. Unlike other skylights, Solatube devices don't go dark when the sun goes down. Equip your Solatube Daylighting System with the optional light kit, and it can provide natural light during the day, plus supplementary electric lighting at night. Alternatively, opt for the Smart LED system, a money-saving solution that combines free daylighting with high-efficiency, low-cost LED technology. Here, whenever natural light levels recede, the Smart LED automatically switches to artificial lighting mode, so you get around-the-clock illumination, sun or no sun. For even more savings, get the optional occupancy sensor, which activates the LED bulbs only when there's someone in the room. That way, you pay only for the LED lighting you need. Brilliant!