Increasing wildfire intensity and frequency will be a prominent land management challenge in the age of climate change, especially along the urban fringe or wildland-urban interface (WUI). The WUI refers to the border where human development abuts unoccupied forest, grass, or shrub land. Wildfires not only present a danger to residential and commercial structures in these areas but also threaten the integrity of the WUI electrical grid through damage to power lines, transformers, or other vital transmission and distribution (T&D) infrastructure. Under the traditional centralized electrical system, a changing climate means higher energy demands and reliance on heating and air conditioning, while more intense weather events increase the likelihood of wildfire along the WUI. Wildfire mitigation efforts, in turn, may require cutting power to these communities during extreme drought or intense weather events, depriving communities on the WUI of life-sustaining power until the connection is restored. On-site energy generation and storage devices placed in these communities as independent microgrids may ameliorate these weaknesses in the electric infrastructure network but also present new challenges and costs in implementation.
The damage caused by wildfire in the 70,000 WUI communities in the United States—representing 99 million people and 46 million homes—is profound. From 2014 to 2020, wildfires in these communities destroyed residential and commercial structures at four times the baseline rate due to “[i]ncreased development of wildland communities, climate change, and drought.” From 2000 to 2016, wildfires in California utilities caused $700 million in T&D-related damages. The wildfire threat to aging energy infrastructure can also be a major cause of fires, with electrical power ranking as “the third-most common cause of wildfires” in California, ahead of arson, lightning, and campfires. These infrastructure-caused fires can be some of the most deadly, such as the 2018 Camp Fire, which destroyed “150,000 acres, 13,972 residences, 526 commercial structures, and 4,293 other buildings, and tragically claimed the lives of 86 people.” Model scenarios suggest that fire damage to infrastructure will continue at this rate through midcentury, while others suggest future fires will far surpass this level in certain regions, such as the Southeast and Northwest of the contiguous United States. The regularity and frequency of fires are also likely to increase because the WUI area continues to grow “by approximately 2 million acres per year” and climate change “will continue to chronically enhance the potential for western US forest fire activity while fuels are not limiting.”
To mitigate the threat of wildfire, utilities such as Pacific Gas and Electric Company (PG&E) have been using strategic cutoffs of power—known as a Public Safety Power Shutoff (PSPS)—to “reduce the risk of their infrastructure to cause or contribute to a wildfire.” California authorizes using PSPS “when strong winds, heat events, and related conditions are present,” and did so 33 times from 2013 to 2019. In the fall of 2019 alone, millions of customers lost power several times. This policy is not ideal as PSPS deprives residents of power for their “daily needs, telecommunications, traffic control and operations, and functioning of critical infrastructure such as hospitals in wildfire emergencies.” These cutoffs will likely increase across the United States as risk-averse utilities attempt to protect their investments and limit their liability from infrastructure-caused fires.
The climate-related threats to the traditional energy sector are also notable in the future liabilities it will impose upon utilities. The 2019 bankruptcy of PG&E is a clear example of this institutional threat to the energy sector’s future viability. The first “climate change bankruptcy” arose from liabilities related to California fires in 2017 and 2018. PG&E “estimated that its wildfire-related liabilities could exceed $30 billion” for the company’s role in causing the fires. While the PG&E bankruptcy involved factors unique to California, the climate conditions that caused the company’s financial distress will continue to occur at greater regularity and severity across the country. The long-term cost to utilities and consumers is difficult to quantify. However, the policy response from California—including $5 billion in safety investments from utilities and a $21 billion insurance fund to be paid into by utilities and ratepayers—is an indication of the scope of risk that utilities will likely face as climate change exacerbates existing risks to the energy sector.
As California and other states prepare to cut power to WUI communities due to frequent high-risk fire conditions and recurrent climate-related damage to infrastructure, WUI customers will see a negative impact on overall energy reliability. However, by shifting away from a centralized T&D model and toward a system of microgrids that can work in both stand-alone and grid-integrated modes along the WUI, the energy system could maintain essential functions even during peak energy demand or high fire risk. This ability for microgrids to store excess energy from distributed generation sources or siphon energy from the grid during times of low demand is also an effective tool in limiting greenhouse gas output from the energy system.
The viability of this strategy in California’s WUI communities is strong, with recent research finding that the optimized use of microgrids in the WUI could maintain the average levelized cost of energy below $0.3/kilowatt-hour and the annual PSPS usage at 2 to 3 percent of the annual energy demand. The greater use of distributed energy generation and storage devices would also mean “renewable energy penetration levels can be maintained above 60% of the annual energy demand.” However, the complete elimination of PSPS energy cutoffs would entail higher costs, with the “higher cost of energy storage [becoming] the bottleneck when eliminating” PSPS. This bottleneck soon may not be an issue, though, as the cost of energy storage fell nearly 32 percent from 2015 to 2017, and energy storage capacity saw a twelvefold increase in the United States from 2016 to If these trends continue through federal and state level support for energy storage technology, the viability of microgrids to meet the energy needs of the WUI holds promise for future grid integrity.
Federal interest in creating a more resilient energy system in the WUI is high. More than $97 billion in investments through the Infrastructure Investment and Jobs Act and the Inflation Reduction Act will go toward “embarking on a new era focused on the rapid commercialization, demonstration, and deployment of clean energy technology.” Specifically regarding energy storage projects, the Department of Energy (DOE) is looking to “improve the reliability of transmission and distribution systems, especially in traditionally high-energy cost rural areas.”
Greater collaboration by federal agencies on fire mitigation indicates an interest in bringing forest management and energy regulation together in shared wildfire mitigation efforts. A 2022 report by the Federal Emergency Management Agency (FEMA) and the United States Fire Administration (USFA) recommends that federal agencies such as the DOE’s Office of Electricity and the Federal Energy Regulatory Commission (FERC) work alongside utilities to design and implement projects “to coordinate and integrate utility wildfire mitigation efforts with [states, local, tribal, and territorial governments’] fire and emergency services.” Additionally, the report recommends that FEMA convene a group of federal agencies to update grant programs, like the Building Resilient Infrastructure and Communities (BRIC), “to better utilize funding at the ground level for wildfire mitigation projects,” specifically in “underserved, rural and tribal communities.”
State-level implementation of microgrids is moving quickly in several parts of the country, with various mechanisms used in the technology’s deployment. Some utilities “have focused their efforts on advancing tariffs and building regulatory frameworks, other states have focused on driving deployment through grant programs.” In the top 10 states for near-term microgrid deployment, “1,000 projects are under construction or plan to come online by 2026.” California is leading the development of microgrid infrastructure with a $200 million Microgrid Incentive Program, which utilities are already using to develop microgrids to achieve “equity and resilience goals for low-income and extreme weather-vulnerable communities.” Especially relevant to WUI communities is the $1.5 million vehicle-to-microgrid PSPS Microgrid Pilot, which would use 200 residential and commercial electric vehicles, solar generation, and utility resources to “energize an isolated distribution line segment during a Public Safety Power Shutoff event and reduce or displace fossil generation.” These programs highlight the promise of microgrid technology in addressing fire risk and grid integrity but require greater investment and planning to resolve these issues fully.
The threat of climate change to developed and undeveloped land is far-reaching in its scope but especially destructive along the border of these environments. Energy infrastructure in the WUI highlights the reciprocal danger of human activity to cause and be affected by climate-fueled wildfires. Continuing and expanding the investment in microgrids along this border will benefit both sides in reducing the potential for environmentally and economically destructive wildfires while preserving the welfare of WUI communities.