As battery energy storage systems continue to surge in popularity, there is a focused concern around the fire risk from thermal runaway in Lithium-ion batteries, overlooking other critical potential fire hazards. Drawing lessons from similar fire risks in wind turbines, Firetrace has developed a holistic and proactive approach that protects the entire asset.
Why are Battery Storage Systems Increasing in Popularity?
Battery Energy Storage Systems (BESS) are at the forefront of the renewable energy revolution, offering a dynamic solution for storing and managing the electricity generated from renewable sources. These systems play a pivotal role in enhancing grid stability, providing backup power, and enabling energy independence. By storing excess energy produced during peak production times, BESS allows for its use during periods of high demand or low production, bridging the gap between renewable energy generation and consumption patterns. 
At the heart of most BESS installations are Lithium-ion (Li-ion) batteries, renowned for their superior energy density and longevity compared to traditional battery technologies. This technology's widespread adoption comes with the responsibility to address its inherent risks, particularly those related to safety and performance standards. 
What are the different fire risks in BESS?
1. Fire and explosion risk due to thermal runaway
A well-studied hazard associated with BESS utilizing Li-ion batteries is the risk of thermal runaway. This phenomenon occurs when a failure or malfunction leads to an increase in battery temperature, triggering a reaction that further raises the temperature, creating a vicious cycle that can lead to fires. The compact and interconnected nature of BESS units exacerbates this risk, as a malfunction in a single component can have a domino effect, compromising the safety of the entire system. The implications of thermal runaway are not just limited to the potential for physical damage; they also pose significant safety threats to individuals and the environment. 
Moreover, BESS units employing Li-ion batteries are vulnerable to off-gassing, a condition where stressed batteries release flammable gases. This issue often accompanies thermal runaway, intensifying safety concerns. Accumulated gases within BESS enclosures can create an explosive atmosphere, poised for ignition by a mere spark or surge in temperature. Notably, some fire suppression systems based on total flooding principles may inadvertently exacerbate this risk by failing to adequately vent these gases, potentially leading to severe explosions that threaten both human safety and environmental integrity, thereby highlighting the necessity for tailored safety measures.
2. Fire risk due to high voltage electronics
BESS fire risks extend beyond thermal runaway, with the Power Conversion System (PCS) presenting significant hazards. Critical PCS components, including transformers, inverters, and capacitor cabinets, are integral to the conversion and management of electrical energy within the storage system. These components can catch on fire due to electrical malfunctions, overheating from high power density, inadequate thermal management, and the stress from frequent charge/discharge cycles on system's components. Fires originating in the PCS can swiftly propagate to adjacent battery racks, rendering the extensive safety mechanisms designed to prevent thermal runaway ineffective. This scenario underscores the complexity of fire risks in BESS, highlighting the need for comprehensive fire protection strategies that encompass all system components. 
Learning our lessons from other clean energy asset fires
BESS is an emerging industry with rapid technological developments, but not all technology used in BESS is new- and neither are all its issues. The Power Conversion System (PCS) components employed in BESS have been in use in wind turbines for a long time now. In wind turbines, these components have been known to cause fires, highlighting the importance of vigilant fire safety measures. When integrated into BESS, especially at the grid or utility scale, these fire risks are magnified due to the system's high power density and inherent thermal management challenges. BESS units, with their dense energy storage and regular charge/discharge cycles, are particularly prone to overheating, heightening the likelihood of fire incidents involving PCS components. This increased risk in PCS installed in BESS containers, compared to their usage in wind turbines, calls for enhanced protective measures to address the unique operational demands and safety considerations of these systems. 
 
Innovative solutions for protecting PCS against fire risks
Firetrace International has more than a decade’s worth of experience working with OEMs, owner-operators, and insurance companies in protecting over 18,000 wind turbines and 45,000 MW of power generation infrastructure around the world. Our offering features a proprietary detection tubing engineered to protect the high-risk electronics found in PCS from fires. The tubing, linked to a cylinder containing a clean agent fire suppressant, is designed to burst upon direct contact with heat or flame. This rupture creates an orifice in the tube, dropping pressure and activating the valve to discharge the clean agent precisely at the fire's source. The chemical clean agent we use is non-conductive, non-corrosive, and non-toxic to humans. With a proven track record in more than 18,000 wind turbines, this technology is ideally suited for PCS in BESS, offering a comprehensive fire suppression approach that protects critical components without damaging the equipment or posing a risk to human health. 
 
Mitigating risks arising from thermal runaway in Li-ion batteries
Firetrace offers two potential solutions to mitigate thermal runaway risks in Li-ion batteries: an aerosol generator system and a chemical clean agent-based system. The aerosol generator floods the container with aerosol upon actuation. This system, specifically designed for BESS containers, stands out for its global track record of successful installations and rigorous testing. Alternatively, our chemical clean agent system employs strategically placed nozzles to deliver a high-pressure agent, effectively containing fires. Both solutions aim to mitigate damage, allow time for contacting first responders, and prevent the fire from spreading to adjacent battery racks or containers. 
When designing a total flood fire suppression system for BESS units, it's crucial to consider the risks associated with off-gassing. These systems must be engineered to not only suppress fires effectively but also to manage or mitigate the accumulation of flammable gases released during battery stress or failure. Incorporating strategies for gas detection and ventilation can prevent the formation of explosive atmospheres, ensuring the fire suppression approach addresses both immediate fire risks and the secondary dangers posed by off-gassing.
 
Protection for alternative battery chemistries 
Firetrace International's fire protection solutions are adept at safeguarding not just Li-ion batteries, but all battery chemistries used within BESS. This versatility ensures comprehensive fire safety coverage, addressing the unique challenges posed by different battery technologies. Each chemistry, with its distinct properties and fire risk profiles, benefits from our tailored fire suppression approaches, enhancing the overall safety of BESS installations. 
 
Comprehensive fire safety in BESS
It is imperative to address not just thermal runaway- but also the broader spectrum of fire and explosion hazards that can compromise BESS integrity and safety. Firetrace International's dedication to advancing renewable energy storage safety is evident in its holistic approach to fire risk management. By providing protection to all battery chemistries and leveraging our experience with PCS equipment in wind turbines, we are demonstrating our commitment to minimizing the potential loss of life and infrastructure. Our dual approach to fire safety, addressing both Li-ion battery fires and PCS-related fire risks, underscores Firetrace International's commitment to comprehensive protection.  
A proactive stance on fire safety is instrumental in fostering the sustainable growth of the renewable energy sector, ensuring that BESS can continue to play a critical role in our energy future securely and efficiently.