By George Harvey
Last January, as the holiday decorations were being taken down in Randolph, Vermont, members of the Chamber of Commerce knew the wreaths and lights had seen their last useful year. They were just too old, worn out, and unreliable. The question was not whether to replace them, but what to replace them with.
“Randolph’s holiday decorations had come to the end of their useful life, and we were striving to find something that was environmentally friendly, and did not require the use of extension cords, light bulb strings, or rely on power from town street poles,” explained Emma Schuman, Director of the White River Valley Chamber of Commerce. They contacted twenty suppliers looking for the lights they wanted, but, Schuman explained, “Every company we called told us the technology was just not available yet.”
Interestingly, they did not have to go all that far to find people who were actually coming up with new technology, and so were better aware and able to deal with the problems at hand. LEDdynamics, a manufacturer of LED lighting and controls, happens to be in Randolph, Vermont. So the Chamber contacted Bill McGrath, the President of LEDdynamics, and McGrath took the challenge on.
Getting electricity to LED lighting without using wires is not a difficult problem. They use very little power, and a small photovoltaic (PV) panel will do very nicely for the small number of lights in a wreath. Adding a battery is not a difficult problem; it is done all the time.
Randolph’s holiday lights, however, show how complicated a simple problem can be. They had to be solar powered in the winter, through cloudy days without much sunshine in the day, but have adequate power for nighttime use. Also, the batteries had to be able to work in the cold, when batteries really do not work all that well. Adding to the problem, a simple photosensor would not do for turning the lights on at night, because the wreaths are on street lights, which fool sensors into thinking it is daytime. Yet another problem was that the system has to be able to adjust output automatically, so the lights can consume less power when a string of cloudy days comes along.
All these problems were solved by LEDdynamics engineers. Each wreath is powered by an unobtrusive solar panel and a battery which, between them, can run the lights through five nights on the power from four hours of Vermont winter sunshine. A microprocessor is in the control unit for each wreath, setting the times for startup and shutdown of the lights. The processor also is able to determine how to set the output of the lights to conserve power.
Now Randolph has fifty wreaths on town streetlights. They are reliably lighted without extension cords. The wreaths are much easier to put up and take down. Since they are so reliable, they can provide a beautiful holiday sight in Randolph. And, since they are from LEDdynamics, they are about as locally-sourced as they could be.
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