Last September, hundreds of thousands of homes and businesses lost power when Hurricane Helen’s torrential rains and devastating flooding devastated western North Carolina. More than a week later, tens of thousands of people remained without it. Thousands of people were left in the dark for weeks and faced problems including water shortages and delays in medical care. But the small mountain town of Hot Springs, North Carolina, lost just 50 percent of the power to critical facilities, including its fire station, gas station, grocery store and cafeteria, even as the swollen French Broad washed away local rivers. It was restored within a day. Single substation.
How was it possible for this town of approximately 520 people to have power restored so quickly? Less than two years later, local utility company Duke Energy was installing a microgrid (a self-sufficient electricity generation, storage, and distribution system) in Hot Springs. Microgrids can become completely disconnected, or “islands,” from the larger power grid during brief power outages, but the 16-mile-long distribution lines that deliver power to consumers are located in rugged and remote areas. It straddles the Pacific Ocean and is vulnerable, so it attacks Hot Springs relatively frequently. From falling tree branches to wind, lightning, and erosion.
Hot Springs’ all-renewable microgrid (using solar panels and battery storage) provided the only electricity for seven consecutive days until a mobile substation was installed to reconnect the town to Duke Energy’s main grid. It was successful as a source. And smaller systems could have run even longer.
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Hot Springs and several other communities across the United States are proving that microgrids powered by renewable energy can strengthen resilience in the face of the worsening climate crisis. Energy experts began promoting this solution several years ago to better protect communities from floods, storms, and wildfires. The idea gained popularity after Hurricane Sandy hit the Northeast in 2012, and gained further traction after Hurricane Maria in 2017, which left many parts of Puerto Rico without power for months. Collected.
“Energy is about more than just keeping the lights on,” says Jenny Brennan, a climate analyst at the Southern Environmental Law Center who co-leads the center’s climate resiliency efforts. “Being able to power medical equipment is critical; it’s about keeping people healthy and safe.”Restoring power quickly is key to saving lives and starting recovery quickly .
How the power grid works
Nearly all electricity in the United States comes from centralized or renewable power plants, which can be very far away from where the energy is used, often across state lines. . High-voltage power lines carry power from power plants to substations that reduce the voltage for residential or commercial use. From there, distribution lines deliver electricity to the building. If one site produces less electricity, another site can make up for it. Ideally, redundancy is built in with many ways to get power from point A to point B.
However, parts of the country’s power grid lack redundancy. One power line in Hot Springs is an extreme example, but it is emblematic of a broader vulnerability. Additionally, power lines and substations deteriorate over time without proper maintenance. “The biggest (energy) threats are related to aging infrastructure,” says Eliza Hotchkiss, a resiliency and recovery analyst at the National Renewable Energy Laboratory. And even if the facilities are well-maintained, they were not built with the current climate in mind. “The dangers of climate change were not taken into account to some extent when energy infrastructure was being built. When[utilities]put in substations, they weren’t necessarily looking at floodplains,” Brennan said. .
In the broader power grid, severe storms, fires, heat waves, freezes, and flooding can knock out centralized power plants. These forces can also disrupt power transmission and distribution systems, preventing power from reaching end users even if it continues to be generated. In some cases, both scenarios occur simultaneously, as in Texas during 2021’s Winter Storm Uri.
In recent years, the duration and frequency of weather-related power outages has increased. From 2014 to 2023, there were about twice as many weather-related power outages in the United States compared to 2000 to 2009, according to an analysis by the nonprofit organization Climate Central. From 2020 to 2022, the average number of hours per year that customers experienced weather-related outages was more than double from 2013 to 2015, according to documents from the Senate Joint Economic Committee.
Brennan helped advise Duke Energy on resiliency assessments for the Carolinas, including major renovations that included replacing miles of utility poles, weatherizing substations and power plants, and burying power lines underground. says all are important long-term solutions. Additionally, investing in energy efficiency should be the first step to increasing reliability and resiliency to reduce strain on the power grid and reduce emissions, according to the Public Utilities Commission of Texas. said Alison Silverstein, an independent energy consultant who advises the Federal Energy Regulatory Commission.
But these fixes can be expensive and time-consuming, often unfolding over a decade or more to accommodate public works budgets, Silverstein said. In contrast, smaller-scale approaches such as microgrids can more quickly and “surgically” secure energy supplies, ensuring power immediately where it is needed most.
Microgrid example
At its most basic, a microgrid is simply a hyperlocal power system. It includes a group of interconnected electricity users and generation, storage, and distribution resources to produce and supply energy in a small area. Microgrids can operate independently from the larger power grid when needed locally, and can also supply energy to the region’s main power grid during normal operation, reducing carbon emissions and costs.
Other communities that have benefited from microgrids during disasters include Babcock Ranch, a developer-planned town in Florida designed to be environmentally friendly with climate resilience in mind. Thanks to its on-site solar power generation facility, extensive stormwater control capabilities, and underground electrical distribution system, it was able to withstand the back-to-back onslaught of Hurricanes Helen and Milton. At Blue Lake Rancheria, a small Native American reservation in northern California, a solar power and battery storage microgrid has helped the community avoid multiple power outages over the past seven years. For example, during active wildfires or multi-county pre-power outages to prevent wildfires. From ignition.
However, microgrids are not cheap, and except in some cases where subsidies support projects, customers end up paying an additional burden on their monthly utility bills. But instead of paying for microgrids and other resilience solutions, we often end up paying a high price for not having them. Power outages make emergency responses more expensive, larger, and more difficult. People are often unable to work, and costs such as food spoilage can quickly add up. “When you take all of these externalities into account, microgrids are often financially viable,” said Dasun Perera, an energy systems researcher at Princeton University.
Perera’s cost-benefit analyzes conducted in California, Chicago, and Puerto Rico show that microgrids are good value for money in all but a few cases, and as solar panel and battery prices continue to fall, the benefits of microgrids continue to rise. will increase further.
Even so, microgrids may not be suitable for every community. Perera found that in some cases, the amount of solar energy that can be produced is “not sufficient to meet energy demands.” To make up the shortfall in such locations, diesel generators would be required, “which would be significantly more expensive to operate,” he said.
Additionally, relative cost remains an important factor. For example, if a town’s energy resiliency can be improved simply by cutting down trees near power lines, implementing a microgrid may be difficult. “Microgrids are not a replacement for the grid,” Perera says, except in the case of islands or isolated communities where energy costs are high.
But our world is changing rapidly, and our energy systems need to keep up. Microgrids are “not a silver bullet,” said Jason Hundley, general manager of Duke Energy’s distributed energy group. But they are “a great tool to have in your toolbox.”
