There have been over 60 reported energy storage fire safety accidents, and the implementation of the new national standard in the future will further improve the performance and safety indicators of lithium battery energy storage.
The thermal runaway inside lithium-ion batteries can cause the battery to burn or even explode, which can be manifested as fires in energy storage stations, electric scooters, and new energy vehicles.
According to statistics from Zhejiang Securities, as of now, there have been over 60 clearly reported energy storage fire safety accidents. In the past month, according to the Beijing Fire Department’s report, on April 16th, a fire and explosion occurred at an energy storage power station in Fengtai District, Beijing, resulting in the sacrifice of two firefighters and the loss of one employee. The site of the fire was the energy storage power station of Beijing Guoxuan Fuweisi Light Storage and Charging Technology Co., Ltd.
An insider in the energy storage industry believes that the increasing capacity of battery cells poses higher challenges to the safety of energy storage systems.
In addition, with the continuous growth of the newly installed capacity of energy storage power stations, energy storage safety also urgently needs to be improved and solved from various aspects.
“Energy storage safety is the bottom line of industry development,” Liu Wei, Vice President and General Manager of the Sensing and Safety Technology Division of Honeywell Intelligent Industrial Technology Group and China, told First Financial reporters that electrical fires are a hidden danger that energy storage power stations need to be vigilant about. During the process of current transmission, short circuits, overloads, and other situations may cause local high temperatures, which can inadvertently ignite combustible materials in electrical equipment.
It is reported that the total number of batteries in energy storage power stations is huge, and real-time detection and timely detection of the thermal runaway status of a certain battery is crucial. When a certain battery is found to have thermal runaway, effective and precise intervention is needed in a timely manner to prevent thermal diffusion.
Liu Wei told First Financial reporters, “The current sensor can be installed in a standard energy storage cabinet to monitor the current information of the high-voltage main circuit in real time and provide feedback to the system, providing current information, implementing overcurrent protection, and conducting current feedback control to ensure the stable operation of the energy storage system.”
According to Liu Wei, the company has launched a fixed point gas leakage detector to address the gas leakage issue in energy storage stations at the warehouse level. This detector is used for gas detection in prefabricated energy storage tanks and is linked with the fire protection system to provide timely alarms and prevent losses caused by thermal runaway.
In addition, from a policy perspective, starting from July 1st this year, the national standard “Lithium ion batteries for electric energy storage” (GB/T 36276-2023) (hereinafter referred to as the “new national standard”) will be officially implemented. The new national standard further enhances the performance and safety requirements of lithium battery energy storage.
In terms of safety, compared to the revised version of the current 2018 national standard, the new national standard proposes requirements for the insulation temperature rise characteristics of battery cells. The new national standard proposes that during the entire life cycle, the surface temperature during thermal runaway should be greater than 90 ℃. Thermal runaway should not cause fire, explosion, or rupture outside the explosion-proof valve or pressure relief point.
Dongwu Securities analyzed that with the continuous growth of the installed capacity of new energy storage power stations and the implementation of new national standards, the safety of the energy storage field will be further guaranteed, and the energy storage fire protection market will also experience significant and rapid development.
“However, considering the encroachment on battery space inside containers further increases the cost of power stations, the high cost requirements for energy storage make PACK level fire protection (referring to fire safety measures for battery packs) more challenging,” said the energy storage industry insider.
Liu Wei believes that some energy storage stations are located in relatively remote areas, and if maintenance is too frequent, the maintenance cost will be high.
According to data from the National Energy Administration, as of the end of 2023, the cumulative installed capacity of new energy storage projects that have been built and put into operation in China is 31.39 million kilowatts/66.87 million kilowatt hours, with an average energy storage time of 2.1 hours. The newly installed capacity in 2023 is approximately 22.6 million kilowatts/48.7 million kilowatt hours, an increase of nearly three times compared to the end of 2022.