Grid Scale, Solar

Traffic Light Revolution includes Photovoltaics and LED

With four million traffic lights consuming 3 billion kilowatt hours of electricity each year in the United States, more cities are saving money with the use of light-emitting diode (LED) bulbs.

ROSEVILLE, California, US, 2001-09-10 [SolarAccess.com] With four million traffic lights consuming 3 billion kilowatt hours of electricity each year in the United States, more cities are saving money with the use of light-emitting diode (LED) bulbs. In Roseville, California, the city’s public works department worked with the local utility to replace all traditional traffic signals with LEDs. Funded in part through a grant from the California Energy Commission, the new lights will save the city 2.3 million kilowatt hours in one year, or US$165,000 in electricity costs. The transition to LED traffic lights sets the stage for the installation of photovoltaic cells and battery backup kits. As funds become available, the city may install the PV panels and backup units to enable traffic signals to operate independently from the grid, further reducing consumption and providing increased traffic safety in the event of power loss. LED technology uses tiny semiconductor-powered bulbs that emit more light than traditional bulbs, at a fraction of the energy use. The small bulbs eliminate the need for coloured filters by emitting red, green and yellow light. The combination of less energy consumption and lack of filtering creates an energy reduction of up to 80 percent compared with traditional bulbs. “The community’s best defense against the effects of the state’s current energy crisis is conservation,” says the utility’s Tom Habashi. “A reduction of this magnitude, combined with other conservation measures to conserve energy, will go a long way to providing a hedge against the possibility of blackouts in Roseville.”