Improving the Scenery: Why Duke’s Solar Microgrid is a Very Unusual Energy Project

While many energy projects run into opposition for marring pristine vistas, Duke Energy last week proposed a solar microgrid that does the opposite. It improves the view.

After installing the Mount Sterling solar microgrid, Duke will be able to take down miles of wire and poles running through a remote mountain region in North Carolina’s Great Smoky Mountains National Park.

“The project is expected to improve service reliability and allow approximately four miles of the utility right-of-way surrounding the existing feeder to return to wilderness status, benefiting the customer and millions of park visitors,” said Jonathan Landy, business development manager for Duke Energy Business Services, in testimony before the North Carolina Utilities Commission.

Located atop Mount Sterling, the project runs counter to the typical story line involving energy infrastructure and beautiful scenery. Energy companies usually find themselves on the other side of the aesthetics argument, confronted by residents angry when wind turbines, transmission lines or even sometimes solar farms interrupt the landscape.

In all, the solar microgrid — which will energize a communications tower — will return about 13 acres of wilderness to its natural state.

And yet the project is pretty small. Costing under $1 million, it includes 10 kW DC solar microgrid with a 95 kWh zinc battery for storage.

Aesthetics aside, the solar microgrid is significant for other reasons too.

First, it represents Duke’s first microgrid built for commercial, not research purposes.

Second, Duke is one of a handful of utilities acting as early leaders in microgrids. The power industry is carefully following the actions of these utilities, seeking indicators about how they will influence the microgrid market and what role they will play.

Third, the project represents growing use of microgrids as ‘non-wires alternatives’ to save money. The solar microgrid will avert the need for “costly upgrades” to the feeder, Duke said.

The microgrid also will improve worker safety. Repairing the feeder line is dangerous because it is in hazardous terrain, according to Duke.

And unlike most North American microgrids, the Mt. Sterling project will be off grid. It is Duke’s first regulated investment in a remote, renewable-based microgrid as well as the company’s first DC-based microgrid.

Solar microgrid to save money

Duke did not make available the amount of money it expects to save from the solar microgrid, citing competitive concerns.

“The microgrid market is still maturing, and Duke Energy would like to protect its investment in this emerging technology,” the utility said in the filing.

The cost savings come from eliminating ongoing operation and maintenance, as well as upgrade costs to the existing four-mile 12.47 kV distribution feeder in Haywood County. Duke plans to de-energize and decommission a portion of the feeder once the solar microgrid is up and running. Without the solar microgrid, Duke said it will need to make high-cost equipment upgrades beginning in 2017

The microgrid will include a ground-mounted, fixed-tilt solar installation and General Electric charge controllers regulating power transfer to loads. It also will incorporate a Fluidic Energy zinc-air battery, which Duke selected in a competitive solicitation. Caterpillar recently made an equity investment in Fluidic Energy and the pair are working together on hybrid microgrids for emerging markets.

Duke hopes to complete construction in mid-2017, so asked regulators for an expedited review schedule. It expects the solar microgrid to have a 25-year life span.

“Although the National Park Service (NPS) will not make a decision about issuing a Right-of-Way Agreement or authorizing construction of the solar-powered system until National Environmental Policy Act (NEPA) and National Historic Preservation Act (NHPA) compliance are complete, the park is pleased to be considered for this project, which could support the sustainability initiative,” said Cassius Cash, park superintendent.

Interested in solar microgrids? Check out Microgrid Knowledge’s library of stories on solar plus storage.