From Compliance to Excellence: Building a Comprehensive Fire Protection System for Energy Storage Containers

As the global energy landscape undergoes a profound transformation, battery energy storage systems (BESS) have become a key technology for grid stability and renewable energy integration. Central to these systems, the energy storage container houses the critical components, yet it also concentrates a significant risk: the inherent thermal runaway of lithium-ion batteries. This phenomenon has indisputably emerged as the most severe challenge to the widespread deployment of energy storage power stations, placing BESS fire safety at the forefront of industry concerns.

What is Thermal Runaway?

Thermal runaway refers to an uncontrollable state where the heat generation rate inside the battery far exceeds the heat dissipation rate, leading to a rapid accumulation of heat, a sharp rise in temperature, and ultimately causing combustion or explosion.

1. Multiple Triggers of Thermal Runaway

l Mechanical Abuse: External physical impacts such as collisions, compression, or punctures can cause damage to the battery cell separator, leading to internal short circuits.

l Electrical Abuse: This includes overcharging, over-discharging, external short circuits, and high-rate charging. These conditions exacerbate side reactions within the battery, generating significant heat and gas, and may also promote the growth of lithium dendrites, which can pierce the separator.

l Thermal Abuse: When the battery in an energy storage container is exposed to high temperatures or the cooling system fails, the internal chemical stability is compromised, triggering decomposition reactions.

l Internal Short Circuits: These can arise from trace metal impurities introduced during manufacturing or lithium dendrites formed during long-term cycling, acting as hidden bombs for spontaneous thermal runaway.

2. Fire Characteristics of Thermal Runaway

Once thermal runaway occurs in an energy storage power station, its characteristics make it extremely difficult to extinguish, demanding specialized smart fire protection strategies.

l High Energy Density and Chain Reaction: Batteries are high-energy carriers with a significant fire load. Thermal runaway in a single cell releases a large amount of thermal energy, rapidly heating adjacent cells and triggering a chain reaction, causing the fire to spread quickly through the BESS container.

l Propensity for Re-ignition: Even if surface flames are extinguished, chemical reactions inside the cells may continue. Once the temperature rises again, re-ignition can occur.

l Release of Toxic Gases: The combustion process releases large amounts of toxic and corrosive gases, such as hydrogen fluoride, carbon monoxide, and hydrogen cyanide, posing serious threats to personnel safety and equipment.

l Challenges in Extinguishing: Traditional extinguishing agents struggle to penetrate into the interior of the cells, thereby increasing the difficulty to effectively cool the core heat source. Therefore, firefighting strategies must combine surface suppression and deep cooling.

Safety Standards of Energy Storage Containers

Related safety standards and regulations clarify a scientific and rigorous framework for the design of BESS containers, effectively addressing complex risks and advancing overall energy storage safety. Key standards include:

• NFPA 855 (National Fire Protection Association Standard for Energy Storage Systems): Focuses on installation spacing, fire protection capacity, ventilation, and overall system limits.

• UL 9540A (Thermal Runaway Propagation Test for Energy Storage Systems): A critical test method for evaluating the ability of the system design to prevent fire spread following a single-cell thermal runaway event.

• IEC 62933-5-2 (Safety Requirements for Energy Storage): Provides comprehensive international guidelines for safety aspects.

• GB 51048-2014 (Chinese Design Code for Electrochemical Energy Storage Power Stations): Serves as a key domestic regulatory foundation.

Compliance is by no means the endpoint, but rather the starting point for safety. It is not only a prerequisite for project approval, securing insurance, and grid connection, but also a core process for validating design concepts and protective measures through empirical data.

Fire Protection of ATESS Energy Storage Container

The fire protection system design of our ATESS energy storage container is built on comprehensive compliance, structured around three core pillars: fire protection components, suppression systems, and integrated control. It delivers robust capabilities, including rapid suppression, sustained cooling, and fundamental prevention of re-ignition, ensuring solid protection for the safe operation of energy storage power stations.

1. High-Precision Fire Protection Components

l Multi-Dimensional Detection: Integrated sensors monitor ambient temperature in the battery compartment, while VESDA or photoelectric smoke detectors enable ultra-early smoke detection.

l AI-Based Thermal Runaway Prediction: Through intelligent analysis of BMS parameters, including voltage and temperature, the system achieves accurate prediction and early localization of potential thermal runaway.

2. Efficient Integrated Suppression System

Our suppression strategy combines fire control with continuous cooling, specifically addressing the re-ignition risk of lithium battery fires:

1. Total Flooding Suppression: Using HFC-227ea (heptafluoropropane) to perform total flooding, ensuring optimal extinguishing efficacy with minimal impact on equipment.

2. Continuous Cooling: An integrated water spray or fine water mist system provides sustained cooling to prevent battery re-ignition.

3. Targeted PACK-Level Suppression: Precision spray technology directs extinguishing agent and cooling specifically to affected battery modules, enabling accurate intervention at the fault point.

3. Smart Integrated Control and Linkage

• Automatic Power Disconnection: In the event of a fire alarm, the system automatically severs the connection between battery packs and the PCS, eliminating electrical risks and cutting off energy input.

• Smoke Extraction and Ventilation: A high-power smoke exhaust system promptly removes high-temperature, toxic, and flammable gases generated during thermal runaway, reducing explosion risks and controlling internal temperature.

• Alarm and Remote Monitoring: Fire alarms and operational data are transmitted in real time to the SCADA or cloud platform, enabling remote monitoring and intervention by operational staff.

Conclusion

The fire protection system within an energy storage container is paramount to the safe operation. We have a profound understanding of the inherent risks associated with lithium-ion battery thermal runaway.

At ATESS, this awareness drives us to meticulously integrate safety into every single component and process. Our commitment is ultimately reflected in the secure and reliable energy storage solutions we deliver, ensuring our clients can deploy with confidence.