A renewable microgrid in flood-hit Hot Springs, N.C., powered the town after Hurricane Helene, reducing outages from weeks to days.

Randy Wheeless | December 30, 2024 | Extreme Weather, North Carolina, Solar, Utilities

In late September, Hurricane Helene bore down on the small town of Hot Springs, N.C. – about 35 miles north of Asheville. Months later, businesses in the town of about 600 are still recovering from the historic flooding.

This may seem like a strange place to report on advancements in renewable energy; however, an innovative microgrid operated by Duke Energy reduced a possible multi-week power outage after the storm to just a few days without power.

Hot Springs Mayor Abby Norton — operating from a makeshift office since City Hall is still damaged — supported the microgrid before it began operating in 2023. The opinion was wait-and-see for the rest of her town in Madison County.

“Residents knew the microgrid was here. But it has only delivered power once,” said Norton. “Now, I think people are glad it’s here.”

The Hot Springs microgrid consists of a 2-megawatt (AC) solar facility and a 4.4-megawatt lithium-based battery storage facility. If an outage occurred, the microgrid was designed to serve the town’s entire power load for 4-6 hours. This timeframe would give the utility sufficient time to repair most routine outages in the area.

Power to the town is delivered by a single distribution line that runs through the Pisgah National Forest, and lengthy outages have happened in the past. Surrounded by a wooded mountainous area, bringing a second line to the town would be an expensive and significant disruption. Backup power with a fossil fuel generator is not an option for the environmentally sensitive area.

In 2018, Duke Energy proposed a solar-and-battery microgrid to serve as backup power for the town.

Microgrids are not new. Many use a natural gas generator to operate. With the solar plus battery setup, the Hot Springs microgrid does not use fossil fuel or produce emissions. Duke Energy’s work on the technology over the past decade allows the microgrid to pick up power from a “black start” situation – where nothing is operating. 

Duke Energy has been testing “renewable” microgrid concepts in its territory. It has provided backup power to fire stations, military installations, communication towers, and emergency operation centers, all of which are either in remote locations or vital facilities that need constant power.

“It is not a silver bullet for every situation. It’s technically complex,” said Jason Handley, Duke Energy’s general manager of the Distributed Energy Group. “But it gives us additional options on how to supply power in areas where continuous power is critical, including remote areas.”

When Hurricane Helene hit the area on September 27, the electrical substation that served Hot Springs, located in nearby Marshall, was basically washed away. Rebuilding it would take months; even a temporary fix could take two weeks. 

While the rebuild was underway, Handley and his team wondered if the Hot Springs microgrid could be configured to serve the town continuously until the substation was back in service.

One immediate challenge was accessing the town of Hot Springs, which, like many areas in the region, was not easily accessible by road. By Oct. 2, the microgrid was able to isolate the town from the rest of the power grid and begin delivering power – continuing to deliver electricity until the main power grid was back in action on Oct. 8.

“The damage in the town reduced the overall demand for power,” said Handley. “That allowed us to use the solar and battery to deliver electricity to downtown Hot Springs all the time – and the rest of the town, all except for some overnight hours. We stretched the capabilities of the microgrid.”

The success of the renewable setup has drawn interest from those concerned about extreme weather and the need for constant electricity – especially in remote areas like Hot Springs. Duke Energy is looking at future locations, and Handley is hearing from other interested customers and utilities hoping to learn more about the technology.

For Mayor Norton, residents are supportive but are waiting for the next important test. “We want it to work when there is an outage during cold weather. That will be key.”