With the global transition toward renewable energy, lithium-ion battery energy storage systems (ESS) have become a vital component of modern power infrastructure. Whether for solar power integration, wind energy storage, or industrial peak shaving, ESS plays a critical role. However, the chemical properties of lithium-ion batteries present safety challenges, particularly the risk of thermal runaway, which can trigger fire incidents.

The complex electrical and chemical environment within energy storage cabinets makes fire detection and suppression a technical challenge. To address this, the industry has developed a multi-level fire protection solution that includes PACK-level, Cluster-level, and Cabinet-level fire suppression mechanisms. These layers work in concert to provide comprehensive safety coverage and minimize fire risks.

Level 1: PACK-Level Fire Suppression-Early Detection and Rapid Response

Principle and Operation

The PACK level serves as the first line of defense in energy storage systems. Each battery PACK—the smallest independent unit in the system—contains multiple cells responsible for energy storage and discharge. Since thermal runaway often originates from individual battery cells, PACK-level fire protection focuses on early detection and immediate suppression.

Key Monitoring Mechanisms:

  ●  Smoke Sensors: Detect early signs of combustion, such as smoke particles caused by thermal runaway.

  ●  Temperature Sensors: Continuously monitor cell and ambient temperatures, triggering alarms if the threshold (e.g., 60°C to 80°C) is exceeded.

  ●  Flammable Gas Detectors: Identify hazardous gases (e.g., electrolyte vapors) released during cell degradation or overheating.

Response Mechanism:

• When abnormal parameters are detected, the integrated fire suppression system immediately deploys FK-5-1-12 (fluorinated ketone), a clean agent fire suppressant.

FK-5-1-12 Properties:

•   ●  Non-conductive: Safe for electronic and electrical equipment.

•   ●  No Residue: Leaves no harmful byproducts, preserving sensitive equipment.

•   ●  Rapid Action: Suppresses fire within milliseconds by absorbing heat and interrupting the chemical chain reaction.

Technical Advantages

•   ●  Independence: Each PACK operates independently, ensuring local anomalies do not escalate into systemic failures.

•   ●  Precision: High-accuracy sensors enable targeted monitoring and suppression.

•   ●  Rapid Response: Fire suppression is executed at the earliest stage, preventing fire propagation.

Applications

Ideal for small-scale and distributed energy storage systems, such as residential energy storage or modular commercial setups requiring fine-grained protection.

Level 2: Cluster-Level Fire Suppression – Regional Management and Intelligent Control

Principle and Operation

At the Cluster level, multiple PACKs are grouped to form a storage cluster. Cluster-level fire protection provides broader coverage and integrates intelligent monitoring systems for proactive risk management.

Monitoring and Data Analysis:

•   ●  Sensor data from each PACK (e.g., voltage, current, temperature, and load fluctuations) are transmitted to a centralized monitoring platform via the Internet of Things (IoT).

•   ●  The system leverages big data analytics to identify risk trends, such as:Gradual temperature increases below the critical threshold.Voltage or current irregularities across multiple PACKs.

Response Mechanism:

•   ●  When a potential fire risk is detected, the system activates the Cluster-level suppression system, which typically uses centralized FK-5-1-12 deployment.

•   ●  Suppression agents are dispersed through multiple nozzles to ensure complete coverage of the affected cluster.

Technical Advantages

  ●  Centralized Management: Enables unified monitoring and control of multiple PACKs.

  ●  Intelligent Risk Analysis: Big data improves preemptive detection, reducing false alarms.

  ●  Regional Isolation: Prevents fire escalation by containing it within the affected cluster.

Applications

Cluster-level fire suppression is well-suited for mid-sized energy storage projects, such as commercial buildings, industrial facilities, or data centers.

Level 3: Cabinet-Level Fire Suppression – Comprehensive Coverage and Final Safeguard

Principle and Operation

Cabinet-level fire suppression serves as the final safeguard in energy storage systems. When fires escalate beyond PACK and Cluster levels, the Cabinet-level suppression system provides comprehensive protection for the entire energy storage cabinet.

Trigger Mechanism:

•   ●  Sensors detect smoke, temperature anomalies, and gas emissions that indicate a significant fire risk.

•   ●  Once critical thresholds are exceeded, the system activates water mist suppression.

Fire Suppression Mechanism:

Water Mist Deployment: Fine water droplets are sprayed across the cabinet interior, achieving dual effects:

•   ●  Fire Suppression: Water mist rapidly cools down flames and suppresses fire.

•   ●  Heat Dissipation: Lowers cabinet temperature, preventing further thermal runaway.

Built-In Safety Features: Water drainage systems prevent accumulation, ensuring equipment integrity post-suppression.

Technical Advantages

  ●  Comprehensive Protection: Covers the entire cabinet interior, ensuring no blind spots.

  ●  Effective Cooling: Water mist effectively reduces thermal runaway spread.

  ●  Redundancy: As the last line of defense, it ensures system-level safety even if previous safeguards fail.

Applications

Cabinet-level fire suppression is essential for large-scale energy storage systems deployed in industrial parks, energy substations, and critical infrastructure facilities.

Multi-Level Coordination: How the System Works

The three-tier fire protection solution is designed to work in a coordinated, stepwise manner, ensuring early detection, regional containment, and full-scale suppression when necessary:

•   ●  PACK-Level Protection:

Provides localized detection and suppression, minimizing damage at the source.

•   ●  Cluster-Level Protection:

Oversees multiple PACKs, uses IoT-driven insights to identify and isolate regional risks.

•   ●  Cabinet-Level Protection:

Ensures overall system safety with comprehensive water mist suppression if earlier levels fail.

This cascading defense approach allows fires to be managed efficiently, mitigating risks and ensuring minimal damage.

Future Directions: Advancing Fire Protection Technologies

While the current multi-level fire protection solutions have significantly enhanced energy storage safety, ongoing technological innovations will further optimize these systems:

•   ●  AI-Based Fire Prediction:

Using machine learning algorithms to analyze sensor data and predict fire risks before they materialize.

•   ●  New Fire Suppression Materials:

Development of low-cost, highly effective, and environmentally friendly agents like low-temperature liquid extinguishants.

•   ●  Enhanced System Integration:

Improving response times by refining the coordination between PACK, Cluster, and Cabinet levels.

•   ●  Standardization:

Establishing industry-wide safety standards to ensure all energy storage systems meet consistent fire protection benchmarks.

Conclusion

The multi-level fire protection solution—comprising PACK-level detection and suppression, Cluster-level intelligent monitoring, and Cabinet-level comprehensive coverage—represents a systematic approach to mitigating fire risks in energy storage systems. This coordinated framework ensures that fires are addressed at the earliest possible stage while providing robust backup mechanisms for complete safety.

As energy storage technology evolves, integrating AI-driven predictions, advanced suppression agents, and standardized safety measures will further strengthen system reliability, paving the way for safer and more sustainable energy solutions.