DARBY, Mont. - The Darby Community Public Library is in its first season as a solar-powered public building.
Sixty-two solar panels were installed in February. Power started flowing in March.
Money for the $58,000 project was funded by Universal Service Benefits grants, which utility customers pay $1 into their power bill. There were also donations.
Despite a cool, cloudy spring the library is already seeing a return in energy savings.
On Tuesday morning library director Wendy Campbell was conducting story time for youngsters.
She said the solar panels now installed on the roof help make the library more self-sustaining.
"Our goal," said Campbell, "is to deliver library services to the community, and by being a self-sustained building we can do that and focus on our mission."
Dan Brandborg showed NBC Montana the panels he installed on the south-facing roof of the building to get the sun's full exposure.
He expects the energy savings to the library will be about $3,100 a year. It's already seeing results.
He said, "88 percent of our annual power needs are being generated on the roof."
Brandborg showed us continual data on the system monitored online. What you could clearly see were spikes on high sun days, one especially for last Saturday when so many of us enjoyed a warm sunny day.
The power collected on the roof moves into the building to run the electrical loads. Any extra power generated hits the electric meter and runs it backwards.
"That gives us a financial credit," he said, "and those credits can be used at night or in the winter when there are times of lower sun."
The Darby community had already designed the library to be energy efficient with a lot of natural light and good insulation.
Plus, said Brandborg,"There are ground-sourced heat pumps for their heating and cooling, which really increases the effectiveness of the solar since it's electrical."
There wasn't much sun showing in Darby Tuesday. But Brandborg said the library was still making enough power to take care of the electrical needs of the building on a cloudy day.
Campbell said it's one more example of how the community used what it "had on hand to build a debt-free library."
It's a library that many call one of Montana's most beautiful public buildings, from the small-diameter timber inside the building that was salvaged from a fire, to that other resource on hand -- the sun.