In Tenderloin district of San Francisco, U.S., the city government has installed "smart" LED (light-emitting diode) street lights, which is part of a wide effort by the city to cut spending and reduce energy use. The LED panels are connected to servers over existing power lines, from which the city manages the operation of the LEDs. Based on data retrieved from the panels, management consoles can remotely turn off or dim lights depending on time, weather and traffic.