What Causes BESS Fire

Understanding Battery Energy Storage Systems (BESS)

A Battery Energy Storage System (BESS) is designed to store electricity in a system of batteries for later use. These systems can range from small residential setups to large-scale installations supporting utility grids. The most common type of BESS today is the lithium-ion battery system, which offers high energy density and low maintenance requirements.

Despite their advantages, lithium-ion BESSs are prone to fire risks due to the high energy density packed into a compact space. This makes it crucial to understand the mechanisms that can lead to a fire in these systems.

Stages of Battery Failure

Battery failure in a BESS typically occurs in four stages: battery compromise, off-gassing, smoke production, and fire. Each stage presents opportunities for intervention to prevent a catastrophic outcome.

1. Battery Compromise: This initial stage can result from thermal, electrical, mechanical, or manufacturing defects. For example, overcharging or a short circuit can lead to internal overheating, while physical damage to the battery container can compromise its integrity.

2. Off-Gassing: Once compromised, the battery’s internal temperature and pressure increase, leading to the release of flammable gases. This stage can last from a few minutes to half an hour, providing a critical window for intervention.

3. Smoke Production: As the battery fails, it produces smoke due to the short-circuiting of the anode and cathode. This is the first step in thermal runaway, a chain reaction where the failure of one battery cell leads to the failure of adjacent cells.

4. Fire: Fire can ensue rapidly after smoke production or continue for hours without flames. The accumulation of flammable gases within the BESS enclosure creates an explosive atmosphere, making fire suppression challenging.

Common Causes of BESS Fires

Several factors can contribute to BESS fires, including:

• Thermal Stress: Internal overheating or external heat sources can compromise the battery.
• Electrical Issues: Overcharging or short circuits can lead to thermal runaway.
• Mechanical Damage: Physical damage to the battery container can expose flammable materials.
• Manufacturing Defects: Faulty components or poor assembly can lead to failure.

Understanding these causes helps in designing better safety measures and interventions to prevent fires.

Interventions to Prevent BESS Fires

Preventing BESS fires requires a multi-layered approach, including:

• Battery Management Systems (BMS): A well-designed BMS monitors the battery’s functions and operating conditions, shutting down faulty cells to prevent failure.
• Gas Detection Systems: These systems detect the release of flammable gases and activate ventilation and alarm systems to mitigate risks.
• Fire Suppression Systems: Specialized fire suppression agents, such as condensed aerosol systems, can quickly suppress fires and limit thermal runaway.

Each of these components plays a crucial role in providing layered protection against BESS fires.

Environmental and Safety Considerations

In addition to fire risks, BESS fires can have significant environmental and safety implications. The release of toxic gases and the potential for explosions pose risks to both human health and the environment. Therefore, it is essential to use fire suppression agents that are environmentally friendly and do not harm sensitive equipment.

Condensed aerosol fire suppression agents, for example, have no global warming or ozone depletion properties and require minimal cleanup after discharge. These agents are effective in limiting thermal runaway and extinguishing fires without causing additional environmental harm.

Conclusion

Understanding the causes of BESS fires and implementing effective interventions are crucial for ensuring the safety and reliability of these systems. By addressing the various stages of battery failure and employing a multi-layered approach to fire prevention, we can mitigate the risks associated with BESS fires.

For more information on how to protect your BESS installations, we recommend contacting Salgrom’s experts. Our team can provide tailored solutions to meet your specific needs and ensure the safety and efficiency of your energy storage systems.