Battery Energy Storage Systems: A Growing Presence in Local Communities

August 13, 2024

By Mike Simpson

This article is reprinted from the 2024 issue of Firefighter Strong.

Utility-scale battery energy storage is often referred to as the bridge between a reliable power grid and building a clean energy future. Battery energy storage systems (BESS) are a flexible energy resource that address many of the challenges facing our electric grid as we work to decarbonize our electricity supply.

Energy storage provides backup for short-term power outages and interruptions; delivers dispatchable energy to meet periods of peak demand; provides ancillary services to maintain the stability of the grid; and supports the integration of renewable energy resources.

For all these reasons, investment and deployment of utility-scale battery storage is accelerating across the country. According to the U.S. Energy Storage Monitor report from Wood Mackenzie, grid-scale energy storage installations in 2023 totaled 7.9 GW, a 98% increase over 2022. In other words, if you don’t already have a BESS facility in your district, you will likely be seeing one before too long.

As the deployment of utility-scale BESS accelerates, questions about the operations and safety of these facilities arise. Fortunately, fire incidents at energy storage facilities are rare and remain isolated. Earlier fires or thermal events have also reshaped the energy storage industry’s approach to BESS system design and safety.

Lessons learned have resulted in the adoption of standards and codes like UL 9540 Standard for Safety of Energy Storage Systems and Equipment and NFPA 855 Standard for the Installation of Stationary Energy Storage Systems, in addition to continual design improvements that energy companies integrate into energy storage facilities. The energy storage technology being deployed today looks and operates very differently from the technology used just a few years ago. And we understand the technical and safety management of thermal hazards to a much greater level of detail today.

For example, at AES all battery cells and modules we deploy now undergo testing according to UL 9540A Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems, both to characterize the hazards associated with battery energy storage fires and to demonstrate the effectiveness of fire mitigation mechanisms. In addition, layered protections are designed to address specific battery failure modes to greatly diminish the likelihood of any singular battery cell failure from cascading into a larger thermal runaway event or fire. Containment, at the cell level, enclosure level, and system level, is key to managing and mitigating thermal hazards in the unlikely event of occurrence.

Although incidents are rare, departments still need to be prepared in the event of a fire or other emergency at a BESS site and train for the unique considerations of such an incident. It is important for local fire departments to engage with BESS operators in their communities to learn about the facility and its safety features, as well as discuss any concerns or recommendations the department has relating to site design to improve response. Departments should also collaborate with the facility operators and other local emergency service agencies to conduct a hazard mitigation analysis and develop pre-incident and emergency response plans regarding the facility. Each site may offer its own challenges and each fire department may utilize different tools or prefer different methods. Early and frequent engagement between BESS operators and firefighters can best serve the safety of the community.

These advancements in BESS technology and standards along with increased collaboration between clean energy project owners and local fire departments are paying off. According to the Electric Power Research Institute (EPRI), “the technology’s overall safety record is strong and improving.” There were about the same number of fires in 2023 as in 2019, even as global battery storage deployments have increased 20-fold. According to EPRI, there were fewer than 10 BESS failure events in the U.S. in 2023.

This is great progress. But there is always more operators and departments can do together to optimize the safety of BESS installations and make sure local firefighters are informed and equipped to respond to any potential BESS-related incidents. At AES, we continually seek new opportunities to work with firefighters to provide information, training materials, and other forms of support as we work together to build a clean and safe energy future.

Mike Simpson is the director of innovation engineering at The AES Corporation and has two decades of experience working with battery energy storage technologies. As a leading provider of clean energy in the U.S., AES is committed to accelerating the future of energy and putting safety first for their people, contractors, and the communities they serve. They joined the National Volunteer Fire Council last year to create new opportunities to work with firefighters to help build and operate clean energy facilities to the highest safety standards.