Battery Energy Storage Systems
Battery Energy Storage Systems (BESS) are essential components of today's energy infrastructure, facilitating the storage and distribution of electricity to effectively balance supply and demand and ensure grid stability. Typically housed in large, outdoor containers containing stacks of battery cells, these battery systems are becoming safer, more stable, and more reliable with each generation.
There is still the potential for critical temperature fluctuations that could lead to fires. Vigilance is vital, as are thermal sensor systems designed to detect signs of damage or failure that often preceed fires.
Battery site operators are particularly concerned with thermal runaway, which can occur when temperatures in a battery cell suddenly spike and spread to other cells, potentially leading to fires and the release of harmful gases. Given how tightly packed these units are, just one overheating due to a fault, damage, or impact can create a devastating cascade within the unit wiping out all assets in a fire that can last for days.
Several incidents at BESS sites in 2024-2025 underscore the fundamental requirement for robust monitoring for thermal runaway. For example, a sizable fire broke out at the Vistra energy storage facility near Santa Cruz, California in January 2025.
The fire released toxic gases, forcing the evacuation of 1500 residents. And it was challenging to extinguish due to the nature of lithium-ion batteries, which may explode when brought into contact with water and can reignite in high temperatures. Among the toxic gases that can be released in a BESS fire is hydrogen fluoride gas, which the US Centers for Disease Control and Prevention lists as an irritant to the eyes, nose, mouth, throat, and lungs.
The U.S. Environmental Protection Agency (EPA) emphasizes that proactive monitoring is a critical component of safe Battery Energy Storage System (BESS) design—particularly when it comes to fire prevention. In its installation guidance, the EPA recommends incorporating remote sensing and early fire detection monitoring technologies, including thermal detection cameras, as part of a comprehensive safety strategy. These technologies allow operators to continuously monitor battery units for abnormal heat buildup, helping identify early signs of thermal runaway or system failure before they escalate into fire incidents.
By deploying thermal fire detection across BESS installations, site operators gain real-time visibility into temperature anomalies that may go unnoticed through conventional monitoring alone. This early-warning capability supports faster intervention, reduces risk to surrounding infrastructure, and enhances overall emergency preparedness—aligning with EPA guidance to integrate advanced detection tools alongside coordinated response planning.
To mitigate the risks to BESS facilities, Flir offers state-of-the-art thermal imaging cameras that are customizable to site size and complexity, offer open platforms for easy integration, and include built-in software for advanced thermal analysis and alarms on potential hot spots.
