Duke Energy has brought into service what is said to be one of the nation's most advanced green microgrids, in the Madison County town of Hot Springs (population 500), North Carolina. The microgrid consists of a 2 MWac solar facility and a 4.4 MW lithium-based battery storage facility. Operation will include reliability services to the electric grid, such as frequency and voltage regulation and ramping support and capacity during system peaks.
"Duke Energy has numerous smaller microgrids on [its] system, but this is our first microgrid that can power an entire small town if its main power line experiences an outage," said Jason Handley, general manager, Distributed Energy Group.
Hot Springs has limited rerouting options should an outage occur. During its testing phase, Duke Energy's microgrid was able to pick up the town's entire load from a black start without any help from the energy grid – using only the solar and battery storage to restore power. The microgrid served the town's load while the company gathered data.
"Through energy storage and microgrids, Duke Energy can enable the integration of more renewables onto the grid and help improve reliability while keeping costs affordable for customers and the communities we serve," added Handley.
Duke Energy worked with the technology company Wärtsilä, which supplied the battery energy storage system for the project, which utilises Wärtsilä's energy management system, the GEMS Digital Energy Platform, for integrated control of both the solar and energy storage facilities.
"The … inverter-only-based community microgrid is a great step forward for Duke Energy and our customers. This project has reduced the need for equipment upgrades in an environmentally sensitive area," said Handley. "We are using lessons learned from this first-of-its-kind installation to take to our other microgrids under construction in Indiana and Florida. At a larger scale, microgrids bring more resiliency to the energy grid for our customers." Duke Energy currently has microgrids supplying over 60 MW connected in its regulated areas.
Image courtesy of Duke Energy