There’s something different about the holiday tree in the Natural Resources Building Rotunda this year: it has lights again. The lights are powered by renewable solar energy. Last year’s tree was not illuminated in accord with DNR’s energy use policy. Thanks to an unrelated DNR solar project, this year’s tree lights up the building’s main lobby area on these dark, western Washington winter days.
The equipment powering the tree’s strands of energy-efficient LED bulbs will be used to power a DNR communications site on an isolated mountaintop in western Washington starting in spring 2013.
Solar power is nothing new for DNR–we’ve used solar power to operate several communications sites and remote automated weather stations for over 20 years. Frequently, these sites are on remote mountain tops where bringing in electrical utility lines would be too costly. Roads leading to those sites can be snowed-in for weeks at a time, which can make the use of propane-powered generators impractical. As the development of solar cells advances, we are now able to produce more power in less light using smaller panels. Recently, we introduced solar power at our Webster Nursery Seed Center office, just outside of Olympia.
We’re into recycling, too: the solar panels supplying electricity to this year’s holiday tree lights were salvaged from a house demolished for a major DNR restoration project at Stavis Creek Natural Resources Conservation Area. (By the way, the tree was donated by a private party.)
How it works
If you happen to stop by the Natural Resources Building in Olympia before January, check out these components:
- Two 75 watt solar panels wired in parallel (Each 18”x36” panel produces approximately 4 ½ amps per hour at the rated 17 volts in full sunlight.)
- TriStar TS-M Solar Controller with digital display. This regulates the battery charge voltage at 13.8-14.2V depending on sunlight exposure. It keeps 12-volt batteries from being damaged (A digital display shows charge voltage and amperage, along with the load power consumed.)
- Two Battery Power Systems TC-1290S 12-volt batteries. Each battery are is rated for 90 amp hours at 12 volts, which means you can pull one amp per hour for 90 hours and maintain a 12 volt output. The batteries are wired in parallel to double capacity, producing 180 amp hours at 12 volts.
After January, you’ll have to hike up a mountain to see this solar equipment in action.
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