Hurricane Helene could force local utilities to rethink grid resilience

It turns out that the crisis wasn’t so dire. Of the 360 substations that were reported down, most ​“were out because of damage to the transmission system that supplies them with power, not necessarily damage to all those substations,” said Brooks, the Duke Energy spokesperson. But even a handful of destroyed substations is no small matter. For at least two sites, the utility has trucked in temporary ​“mobile substations” that will power nearby communities until the equipment can be repaired.

In normal times, said John Wilson, a vice president at the consulting firm Grid Strategies, it takes over a year to build a new substation from scratch, including drawing up a site-specific design and procuring the equipment. Rebuilding can be a significantly shorter process when the designs are already complete, and utilities keep some amount of equipment in reserve. But the depletion of those reserves will only add to the potential supply chain bottleneck for future crises.

Global demand for transformers is growing, in part because the transition to renewable energy will require many more sites of power generation than the old fossil-fuel-powered system — and each new power plant requires its own equipment. With few manufacturers of transformers operating in the U.S., utilities must wait an average of 150 weeks for an order to arrive.

While it’s unclear whether the storm recovery will be directly impeded by the transformer shortage, it may breathe life into solutions that have been recently proposed. In September, the president’s National Infrastructure Advisory Council recommended that the federal government create a strategic reserve of transformers to bypass the industry’s long lead times. And in a report published in August, Grid Strategies recommended that utilities band together in a collective procurement organization — ideally with federal loan backing — to make large orders and share the costs. ​“That would help deal with the construction backlog; right now, manufacturers are hesitant to build new factories to build this equipment in the U.S. or North America because they aren’t confident that the market will be there,” said Wilson.

The reconstruction of the power grid in the areas of Appalachia where it was wrecked by Helene will ultimately offer a chance for the utility industry to rethink how the electricity system should be structured. “​In areas where there could be more extreme weather events like this, it’s going to be more and more difficult to maintain far-flung distribution systems,” Norris said. ​“And the cost of service is going to rise, and you either have to muddle through that or think about other measures, like undergrounding lines, or trying to bring load into higher degrees of concentration so it isn’t so far-flung, or, obviously, to think more about distributed energy systems and backup power.”

There are ways to build grid resilience that could be implemented on a more local level — although they’re costly. One is the concept of microgrids — local electric grids that are disconnected from the wider power system. Norris said this concept could be extended further by allowing individual homes and businesses to power themselves with rooftop solar when the grid is down. Most solar arrays aren’t configured to produce power when there isn’t a wider grid to feed them into, in order to protect the line workers repairing power lines from a live current. But this can be prevented by a technique called solar islanding, which effectively disconnects the solar array from the grid.

Last week, Duke Energy used one such microgrid in the flooded resort town of Hot Springs, North Carolina, to keep the lights on downtown for days using only batteries and solar power. For towns like Hot Springs, microgrids could be much more than temporary patches.