[Energy Storage Safety] Is Your BESS Container Really Safe?

Energy Storage Safety: An Underestimated Risk

In 2023, more than 40 BESS (Battery Energy Storage System) fire accidents occurred globally, several of which caused major property losses and casualties.

However, against the backdrop of rapid expansion in the energy storage industry, safety issues are often ignored by the "deploy first, improve later" mentality.

A core question: Is your BESS container really safe?

Thermal Runaway: The Core Threat to BESS Safety

Understanding BESS safety must start with lithium battery thermal runaway.

Thermal runaway is a self-accelerating chemical reaction process:

1. Trigger phase: Overcharging, overheating, mechanical damage, or manufacturing defects trigger initial reactions
2. Acceleration phase: Rising temperature causes SEI membrane decomposition, releasing heat and flammable gases
3. Runaway phase: Temperature exceeds critical point, reaction becomes irreversible, large amounts of heat and gas released
4. Propagation phase: Heat and gas conduct to adjacent batteries, triggering chain reactions

Key data:

• Temperature of a single battery in thermal runaway can exceed 800°C
• Released gases (CO, H₂, CH₄, etc.) are highly flammable
• From thermal runaway onset to explosion may be only seconds to minutes

Three-Layer Active Protection System

Facing thermal runaway threats, TKC's BESS safety protection solution adopts a three-layer active protection system:

First Layer: BESS Vent — Controlled Venting

Core Product: BESS Vent Controlled Venting System

When thermal runaway occurs, large amounts of flammable gas rapidly accumulate inside the container. The BESS Vent system's function is: before gas concentration reaches the lower explosive limit, safely vent the gas through controlled venting, preventing the formation of explosive mixtures.

Key characteristics:

• Response time: millisecond-level
• Venting direction: controllable, avoiding discharge toward personnel gathering areas
• Anti-flashback design: preventing external flames from entering through venting ports

Second Layer: Vent PRO — Active Pressure Relief

Core Product: Vent PRO Pressure Relief System

When internal container pressure exceeds design values, the Vent PRO system provides active pressure relief channels, preventing structural damage to the container.

Differences from traditional explosion vent panels:

• Traditional explosion vent panels are passive response; Vent PRO is active control
• Can be precisely controlled based on pressure sensor signals
• Can automatically reset after pressure relief, reducing downtime

Third Layer: DivEx — Directional Guidance

Core Product: DivEx Directional Guidance System

When the first two layers of protection cannot fully control the situation, the DivEx system directs explosion energy to preset safe directions, minimizing harm to surrounding facilities and personnel.

Design principles:

• The direction of explosion energy guidance is determined in the design phase
• Avoid directing toward adjacent BESS containers to prevent chain reactions
• Coordinate design with building structure to ensure guidance channels are clear

Special Challenges of ISO Container Structure

The structural characteristics of standard ISO containers bring special challenges to BESS safety protection:

Challenge 1: Sealing ISO containers have good sealing, which is beneficial for waterproofing and dustproofing, but unfavorable for gas venting during thermal runaway.

Challenge 2: Structural Strength ISO container structural strength is designed to withstand stacking and transportation loads, not internal explosion pressure.

Challenge 3: Space Constraints The internal space of containers is limited; installation of protection systems needs to be coordinated with battery modules, BMS, and other equipment.

TKC's BESS-DLC system has been specially designed to address these challenges, providing effective active protection capabilities while maintaining the structural integrity of the container.

Certification Standards

BESS safety protection systems should meet the following standards:

• NFPA 68: Deflagration Venting Guide
• EN 14797: European Explosion Venting Equipment Standard
• FM 4440: Hazardous Material Storage Container Certification
• UL 9540A: Energy Storage System Fire Test Standard

Conclusion

BESS safety is not an "optional configuration" but a basic requirement for energy storage projects. As energy storage projects grow in scale and density, the importance of safety protection will only increase.

When planning BESS projects, safety protection systems should be designed simultaneously with battery systems, not added as an afterthought.

Is your BESS container really safe? This question deserves a serious answer.