BESS Safety

Alpha Omega Power's team of skilled professionals possesses decades of power and battery industry expertise and experience. AOP uniquely understands our evolving power grid needs and commits to deploying the safest, novel technologies for all AOP Battery Energy Storage System (BESS) facilities.

Simply put, Battery Energy Storage Systems (BESS) allow energy to be safely stored for times when it is needed. As California, Texas, and the United States continue the transition to a clean and reliable grid, a BESS is essential in guaranteeing a reliable supply of power, even during times of peak demand. BESS can also deliver lower costs for businesses and households while reducing carbon emissions.

Yes. Battery Energy Storage Systems (BESS) are extremely safe.

According to the U.S. Energy Information Administration, there is approximately 21 Gigawatts (GW) of commercially operational battery capacity deployed in the U.S., up from 1 GW just four years ago, and that number is expected to reach 30 GW by the end of 2025.

AOP BESS projects are fully compliant with extremely restrictive fire codes developed by the National Fire Protection Association (NFPA) in 2020 and 2023. NFPA 855 is the benchmark for all projects in this field and includes extremely well-documented, fact-based requirements for energy storage. Our projects meet NFPA 855 code requirements and, in many cases, go above and beyond them.

While there have been fire incidents at older energy storage facilities, these occurrences are very rare. The design and technology of BESS systems have evolved tremendously in the past few years, and the industry's approach to safety has advanced in tandem — most notably, the adoption of NFPA 855 and UL 9540 standards. UL 9540 is the American and Canadian National Safety Standard for Energy Storage Systems and Equipment.

Incidents have occurred in the last decade involving lithium-ion Battery Energy Storage Systems (BESS). The National Fire Protection Association assembled an expert team under its standard 855. The first version of NFPA 855 was published in 2020 and continues evolving with over 25 of the nation's best experts contributing to put an end to BESS fire hazards. Since the 2020 NFPA release, no BESS fire has caused any injury or third-party property damage in the U.S.

AOP projects are subjected to rigorous tests to meet all the latest applicable codes and standards, working in close coordination with local fire departments. This includes all applicable BESS tests and standards (NFPA 855, 69, 72, 70, UL 9540, UL 9540A, UL 1973, IEEE 485).

Our systems are exposed to:

1. Lithium-ion cell ignition tests to verify that an internal electrical or chemical malfunction ("thermal runaway") will not propagate to create a full block fire.
2. Torching tests at the unit level to verify that fire does not propagate should a major external fire occur.

Our batteries have demonstrated very low flammability, and the fire-safety authorities overseeing each project rigorously review all documentation. The projects are built and tested by leading design and construction companies, with electrical site work performed by IBEW personnel to ensure the highest standard of safety and quality.

The utility-scale BESS technology used today looks and operates very differently from the technology used just a few years ago. Modern AOP projects incorporate today's most advanced technology and safety standards and undergo rigorous testing to meet or exceed all the latest applicable codes and standards.

AOP projects are distinctly different from older battery storage sites for two key reasons:

1. Safer battery chemistry. AOP uses Lithium Iron Phosphate (LFP) batteries, which feature the highest-rated safety metrics and performance — far superior to the older, less stable chemistries used in 2015–2018 era projects.
2. Containerized design. AOP projects use a modular, outdoor design rather than packing batteries into a single legacy building. Each battery container has its own batteries, continually monitored with sensors, controls, and safety equipment. At Moss Landing and Otay Mesa, outdated batteries were placed together in one building without adequate fire sensors or suppression. In the very unlikely event an incident occurs at an AOP site, it is contained to an individual container and cannot spread to neighboring units.

No. Deflagration has been known to happen in cases of unmitigated thermal runaway in BESS housed in buildings. AOP projects are entirely outside, and all units are thoroughly tested to stop thermal runaway rapidly. In addition, they comply with NFPA Code 69, and each unit's venting system is tested to verify it will dissipate any dangerous gas in the unlikely case of a thermal runaway.

AOP batteries are tested against propagation. Plume analysis shows that even in a worst-case scenario — an entire battery container fully engulfed in flames — smoke would be below toxicity levels at 110 feet from the center of the fire. This scenario is nearly impossible given the NFPA 855 safety measures in place. NFPA 855 did not exist at the time legacy projects like Moss Landing were constructed.

Rigorous environmental monitoring and comprehensive studies — including those conducted by the New York State Energy Research and Development Authority (NYSERDA) — have consistently demonstrated that previous fire incidents involving BESS have not posed a significant risk to public health. The risk of modern BESS fires is comparable to other common risks, such as residential fires.

Following the February 2025 Moss Landing fire, officials reported:

• Monitoring by the U.S. EPA found levels of particulate matter and hydrofluoric acid posed no risk to the public.
• The Department of Toxic Substance Control found no soil contamination.
• The Monterey Bay Air Quality District detected no directly associated impacts.