| by Sustainability Coordinator Kevin Bright

One of the photovoltaic-powered lights being tested.

Colby installed solar-powered parking-lot lights in a new parking area adjacent to the soccer/lacrosse field and is evaluating their performance this fall.

The two units use highly efficient LED lamps powered by photovoltaic cells located at the top of the fixture. During the day the photovoltaic panels convert sunlight to electricity, which is stored in batteries located in the base of the light fixtures. Photocells turn the battery-powered lights on when it gets dark. The light fixtures are also equipped with timers that turn off the LED lamps late at night and with motion sensors to turn the lights back on when someone is in the area.

As a result of the photovoltaics and batteries, the fixtures are completely self-sufficient and are not connected to an external power source. Typical exterior light fixtures for parking lots would use 200 to 250 watts when illuminated—power that would have to be purchased from the grid. The LED lamps consume approximately 75 watts, representing a great energy savings. The combination of a more efficient lighting source and an intelligent motion-sensor control system, creates a system that captures and stores energy by day and operates at night.