When Hurricane Helene’s rains and flooding devastated western North Carolina last September, hundreds of thousands of homes and businesses lost power. More than a week later, tens of thousands were left without it. Thousands were left in the dark for weeks and faced problems such as water shortages and delayed medical care. But the small mountain town of Hot Springs, N.C., restored power to critical facilities — including a fire station, gas station, grocery store and diner — in just five days, even as the swollen French Broad River wiped out the community. the only electrical substation.
Why was this town of about 520 inhabitants so quick to regain power? Less than two years earlier, regional utility Duke Energy supplied Hot Springs microgrid: an autonomous system for generating, storing and distributing energy. The microgrid can be completely disconnected, or “islanded,” from the larger power grid during brief outages, which hit Springs quite often because the 10-mile distribution line that carries electricity to consumers spans steep, remote terrain and is vulnerable. falling tree branches, wind, lightning and erosion.
Hot Springs’ fully renewable microgrid (which uses solar panels and battery storage) was the only source of electricity for seven straight days until a mobile substation could be brought in to reconnect the town to Duke Energy’s main grid. And the small-scale system could work even more.
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Hot Springs and many other US communities are proof that renewable energy microgrids can increase resilience to the worsening climate crisis. Energy experts began promoting this solution years ago to better protect communities from floods, storms and fires. The idea gained popularity after Hurricane Sandy hit the Northeast in 2012, and gained additional buy-in in several parts of Puerto Rico after months without power after Hurricane Maria in 2017.
“Energy isn’t just about keeping the lights on,” says Jenny Brennan, a climate analyst at the Southern Environmental Law Center, where she leads climate resilience work. “It is to be able to feed the medical equipment. It’s about being able to keep people healthy and safe.’ Rapid energy recovery can be critical to saving lives and starting recovery quickly.
How the power grid works
Almost all electricity in the US comes from centralized power plants or renewable generation sites, which can be very far — often across state lines — from where that energy is used. High voltage transmission lines move from energy generation points to substations that reduce voltage for residential or commercial use. From there, distribution lines carry the electricity to the buildings. If the generation is low in one site, another can compensate. Ideally, redundancy is built in, with multiple ways to get power from point A to point B.
However, parts of the nation’s network lack redundancy; The single distribution line in Hot Springs, while an extreme example, is indicative of a broader vulnerability. In addition, lines and substations have deteriorated over time without proper maintenance. “The biggest (energy) threats are related to aging infrastructure,” he says Eliza HotchkissResilience and recovery analyst at the National Renewable Energy Laboratory. And even when the equipment is well maintained, it was not built with our current climate in mind. “To some extent, climate risks were not taken into account when the energy infrastructure was being built. (Utility companies) when they were siting substations, they didn’t necessarily look at the flood plain,” says Brennan, citing the loss of the Springs substation during Helene as an example.
In the wider grid, severe storms, fires, heat waves, freezes or floods can render centralized generation plants inoperable. These forces can also knock out the transmission and distribution systems, so even if the energy continues to be generated, it cannot reach the end user. Sometimes both scenarios occur at the same time, e.g Texas during the 2021 winter storm Uri.
In recent years, weather-related power outages have increased in duration and frequency. From 2014 to 2023, the US experienced twice as many weather-related outages as from 2000 to 2009. an analysis from the non-profit organization Climate Central. From 2020 to 2022, this was the average number of minutes per year that customers experienced weather-related outages. More than double from 2013 to 2015According to a document from the Senate Joint Economic Committee.
Major upgrades like replacing miles of utility poles, weathering substations and power plants or moving underground lines are important long-term fixes, says Brennan, who helped advise Duke Energy. resilience assessment from Carolina And investing in energy efficiency It should be the first step in protecting reliability and resilience as it lowers grid stress and reduces emissions, says the independent energy consultant. Alison SilversteinHe has advised the Public Service Commission of Texas and the Federal Energy Regulatory Commission.
But these repairs can be expensive and slow, and often take more than a decade to complete because utilities have their budgets, Silverstein says. In contrast, small-scale approaches, such as microgrids, can more quickly and “surgically” protect energy supplies, ensuring power is immediately where it is needed.
The case of microgrids
At its most basic, a microgrid is simply a hyperlocal electricity system: a group of interconnected electricity users and resources for generating, storing and distributing energy to produce and deliver it in a small area. Microgrids can operate locally in isolation from the larger grid when needed, while also providing power to a region’s main grid—and reducing carbon emissions and costs—during normal operations.
There are other communities that have benefited from microgrids during disasters Babcock Rancha developer-planned Florida town designed to be eco-friendly with climate change resilience in mind. It withstood the brunt of Hurricanes Helene and Milton thanks to its solar farm, extensive stormwater control features and underground electrical distribution system. At Blue Lake Rancheria, a small Native American reservation in northern California, a solar and battery storage microgrid has helped the community avoid blackouts several times over the past seven years, including during an active wildfire and Proactive multi-country blackout to prevent wildfires.
Microgrids are not cheap, however, and except in some cases where subsidies support a project, customers take an extra burden on their monthly bills. However, the alternative to paying for microgrids and other resiliency solutions is often paying a higher price for not having them. Disruption makes emergency response more expensive, more extensive, and more difficult. People are often unable to work, and the cost of food spoilage, for example, can add up quickly. “If you factor in all these externalities,” microgrids are often financially viable, he says Dasun PereraPrinceton University energy systems researcher.
In the cost-benefit analyzes carried out by Perera in California, Chicago and Puerto Ricomicrogrids are worth the price in all but one case, and will become more advantageous as the price of solar panels and batteries continues to drop.
However, microgrids may not be suitable for all communities. Perera observed that in some cases, the amount of solar energy that could be generated “was not enough to meet the energy demand”. Diesel generators would be needed to get moxa in such places, and “the operating costs are quite high,” he says.
Also, relative cost is still a factor. For example, if a town improves energy resilience by cutting down some trees near power lines, a microgrid can be a tough sell. Except in the case of islands or isolated communities where energy costs rise, Perera says, “microgrids are not a substitute for the grid.”
However, our world is changing rapidly, and energy systems must keep up. Microgrids “will not be a silver bullet,” says Jason Handley, CEO of Duke Energy’s Distributed Energy Group. But they are “a great tool in the toolbox.”
