Duke Energy got the official go-ahead for a renewable energy project that’s drawing praise from some of its most frequent critics. The “microgrid” system, atop Mount Sterling in the Great Smoky Mountains National Park, represents Duke’s latest, small foray into linking solar energy to battery storage – a combination that experts say is key for the expansion of renewable energy.
At Mount Sterling, about 40 solar panels could generate up to 10 kilowatts of power, twice what a typical home would need. Energy produced during the day will be enough to power the park’s emergency radio tower.
Excess electricity will be stored in a 95-kilowatt-hour, non-toxic zinc-air battery – the same technology often used in hearing aids and heart-monitoring devices. When it’s too dark or cloudy for solar panels to work, the battery will supply the tower.
The “microgrid” system is entirely self-sufficient, allowing the removal of power lines that currently connect the radio tower to Duke’s electric grid.
“They did the numbers and found it was less costly to build, versus replacing four miles of transmission line up a rugged terrain,” said Jack Floyd, an engineer with the North Carolina Public Staff, the state-sanctioned ratepayer advocate.
Removing the transmission lines also restores 13 acres of parkland on Mount Sterling, named when early settlers mistook lead for silver in the nearby Pigeon River. It’s considered one of the Smokies’ most historic spots.
“Mount Sterling is a very popular place to go,” said Julie Mayfield, co-director of Asheville-based Mountain True, which advocates on a range of environmental issues in the region. “When you’re deep in the Smokies and you’re hiking, not having transmission lines is going to be a real benefit.”