Traffic light
Converting traffic control lights to solar power and LEDs makes sense from both an environmental and cost-saving point of view. Converting an existing signal is as simple as replacing the light unit and hooking it up to a solar panel.
Basics
A solar panel is attached to the traffic control. Light strikes the photovoltaic cells and is converted to electricity which charges a battery. Solar traffic lights use LEDs which are both energy-efficient and very bright.
Function
Temporary traffic lights rely on a timer or a radar sensor to let traffic through. Permanent lights are linked by radio, with a main control unit run by computers.
Cost Savings
Solar traffic controls save cities money on their electricity bill. According to Outdoor Solar Lights, an eight-light set draws as much power as a family of four living in a three-bedroom house. LEDs can last up to 100,000 hours and draw from around 6 to 13 watts. (A normal household bulb is 60 to 100 W.)
Practicality
Existing lights can be converted to solar power. Solar traffic controls are helpful in developing countries where power outages are a fact of life. Installation of the lights can be done by one to two people without difficulty.
Fun Facts
Solar power is used in traffic controls but also in signs. Boston, Mass. established an evacuation route using solar power. Ontario, Ore. installed solar-powered school crossing warning lights.
