Research on Thermal Runaway Safety Protection Technology for Battery Energy Storage Systems in High Altitude Complex Conditions
On March 20, 2025, the China Electricity Council released 24 typical cases of innovation and application in the electrochemical energy storage industry, aimed at promoting safe, high-quality development within the sector by sharing successful experiences and best practices. The latest case presented is the “Research on Thermal Runaway Safety Protection Technology for Battery Energy Storage Systems in High Altitude Complex Conditions.” This collection of cases will also be showcased at the Third China Energy Storage Conference on March 27, 2025.
1. Project Overview
The 120,000 kW photovoltaic power supply project in the Sening District of Naqu City, Tibet, is currently the largest photovoltaic project in the region, requiring a 30 MW/120 MWh energy storage system. The project site features high altitude, low air density, low average annual temperatures, significant temperature variations between day and night, dry climate, frequent thunderstorms, strong ultraviolet radiation, challenging environmental conditions, and limited local population mobility.
This project establishes a thermal runaway testing platform for battery modules and a fire safety early warning and graded protection system for battery storage systems. The goal is to prevent thermal runaway spread between battery cells, achieve cooling, reduce power, halt operation, and implement graded fire control, thereby creating a comprehensive safety protection technology system for energy storage systems.
2. Solutions
Implementing thermal runaway safety protection for battery energy storage systems in high-altitude environments is crucial for ensuring the safe operation of energy storage plants. Safety issues in energy storage plants are systemic and can stem from various causes, often resulting in fire or explosion. The primary causes of safety incidents include battery defects, external triggers, operational environment factors, and management system failures.
Key Factors of Safety Incidents:
- Battery Defects: Issues during manufacturing or aging can lead to safety degradation, potentially causing internal short circuits and localized overheating, resulting in thermal runaway.
- External Triggers: External electrical, thermal, or mechanical stimuli can incite thermal runaway reactions, releasing flammable gases and causing explosions.
- Operational Environment: Lithium batteries must operate within safe parameters; poor environmental conditions can compromise reliability and lead to accidents.
- Management System Failures: The management system is the core control and decision-making unit of the electrochemical storage system. If the system lacks viable internal safety designs, a single battery failure can lead to overall system loss of control.
Thus, developing thermal runaway protection technologies suitable for high-altitude environments is vital for the safe operation of energy storage plants and is a necessary trend in the advancement of battery energy storage systems.
Proposed Solutions:
- Thermal Barrier Protection Technology: To address the challenges of thermal runaway spread in battery modules under high altitude, large temperature variations, and high radiation conditions, a testing platform has been developed to analyze thermal barrier materials’ effectiveness in various configurations. The aim is to ensure no thermal runaway spread occurs between battery cells, with no open flames outside the battery cluster.
- Fire Safety Early Warning and Graded Protection Technology: To rectify issues of inadequate safety designs in battery storage systems under harsh conditions, this project employs a comprehensive approach to disaster management, from preemptive intervention to post-incident containment and extinguishing. This includes precise diagnostics and early warning technologies, along with strategies for cooling, power reduction, shutdown, and fire control.
3. Key Points and Innovations
(a) Research Foundation
Over the years, BYD Auto Industry Co., Ltd. has pioneered the use of lithium iron phosphate battery technology in energy storage systems by introducing blade batteries, capitalizing on their high safety and low cost. This has resulted in a product with a high safety rating. The cumulative shipment of these batteries has exceeded 20 GWh, distributed across over 400 cities globally, with a zero percent accident rate. In collaboration with partners, technical challenges such as battery parallel current control, liquid cooling, and system integration have been successfully addressed, leading to over 5 GWh of installed liquid cooling energy storage systems.
(b) Innovations:
- Analysis of the unique characteristics of high-altitude sites has informed the technological requirements:
- High altitude and thin air lead to weaker convective cooling and higher risks of air breakdown.
- Low average annual temperatures and significant temperature swings necessitate stringent temperature control measures.
- Dry climate and low humidity increase static electricity risks, requiring lightning protection.
- Strong solar radiation affects the lifespan of exposed equipment.
- Long distances for equipment transport and low local population density require rigorous maintenance protocols.
- Addressing the four main causes of safety incidents with targeted thermal runaway protection technologies for battery energy storage systems in high-altitude environments.
4. Practical Effects
The implementation of this project will foster long-term collaboration between academia and industry, significantly promoting the conversion of theoretical research into practical applications, aiding the transformation and upgrading of the energy storage industry. The research outcomes will enhance the safety performance of battery energy storage systems, reducing ecological pressures from fire and explosion incidents and ensuring the safety of lives and property.
5. Economic Benefits and Promotion Prospects
Battery energy storage is a well-established technology expected to see rapid growth during the 14th Five-Year Plan period, with installed capacity projected to exceed 30 million kW by the end of 2025. This project will effectively address safety technology challenges across the entire lifecycle of battery energy storage systems, supporting healthy large-scale development in the sector and enhancing the competitive edge of the new energy industry internationally. The rapid growth of the energy storage industry will also drive advancements in safety-related sectors such as fault diagnosis, early warning, and fire protection, presenting vast market opportunities.
Since the project began operations on December 8, 2022, it has generated 22,722 MWh of electricity by the end of June 2024, yielding revenue of 76.38 million yuan. With effective support from the thermal runaway testing platform and fire safety systems, the energy storage system operates safely and stably.
