How To Solve Energy Storage Safety Issues

In the early morning of April 17th, 2021, the official Beijing fire department reported on Weibo that at 12:17 on April 16th, Beijing 119 Command Center received the report that the energy storage power station in No. 14 yard A, Dahongmen Ximachang, South Fourth Ring, Fengtai District, was on fire.  At about 14:15, during the disposal of the southern part of the power station, the northern part of the power station exploded without warning, resulting in the death of 2 firefighters and one firefighter injured (in stable condition). One employee lost contact inside the power station. After preliminary investigation, it was found that the fire site was the energy storage power station of Beijing Guoxuan Fuweisi Optical Storage and Charging Technology Co., Ltd. Before the incident, the power station was undergoing construction and commissioning.

Once it fired don’t panic. In theory, the safety of energy storage projects can be solved by engineering and technical means, so there is no need to cause panic. The energy storage accidents currently encountered are mainly because some technical thresholds and safety measures are not strictly in place.

Second, do not simply attribute the accident to battery selection. At present, the main reason for energy storage safety accidents is that lithium batteries are flammable and accompanied by thermal runaway, but the accidents are often not batteries. We see more causes are caused by electrical accidents. Safety is a complex system, which cannot simply be attributed to the choice of battery, and the supporting system is equally important.

Third, don’t lower costs at the expense of safety measures. At present, the bidding price of domestic energy storage projects is approaching the cost price, and the project must be launched in the short term. On the one hand, low cost limits the investment in system security measures; on the other hand, hasty delivery will result in a short system test and verification period, which makes it impossible to fully demonstrate safety.  Therefore, achieving acceptable technical and economic efficiency under the premise of ensuring safety is a challenge that needs to be overcome in the development of the energy storage industry.

Fourth, we must advance the formulation of safety standards and related regulations as soon as possible. After an accident, the real cause of the fire must be found out, and solutions and rectification measures must be formulated for the problem. As for the lagging or blank related standards and specifications, relevant departments should also step up research, formulation and promulgation. The Zhongguancun Energy Storage Industry Technology Alliance (CNESA) has also successively carried out research and formulation work on alliance standards, specifications, testing and certification, etc. in response to energy storage safety needs. It is currently formulating comprehensive evaluation indicators for energy storage systems and planning to carry out related evaluation work to promote the industry Healthy and orderly development.

Fifth, we must go through full demonstration and safety assessment before the energy storage project is officially put into operation. In the past year, there have been fire accidents in lithium battery projects in China, South Korea, and Belgium. However, mainstream manufacturers of lithium batteries have maintained a relatively low accident rate in the European and American markets. The safe use of some projects has exceeded 8 years, and there are many valuable experiences abroad. Has been transformed into norms and standards. This fully shows that although lithium batteries have the risk of flammability and thermal runaway, the safety of lithium battery energy storage systems can be guaranteed through strict and effective management and control, raising the barriers to entry from a safety perspective, and undergoing sufficient safety testing and authoritative certification.

Sixth, we must pay attention to the development of new water electrolyte batteries. For large-scale energy storage power stations, safety must be the top priority of all issues that need to be considered. As an operating unit, energy storage power stations have economic benefits. They should use batteries with high energy conversion efficiency, long life, low cost and operating costs, and proper consideration of specific energy. Therefore, the development and application of new water electrolyte batteries should be highly valued at present:

1. Vigorously develop new flow batteries with energy conversion efficiency higher than 80%, cost less than 2 yuan/watt-hour, and cycle life up to 10,000 times; existing flow batteries should also be raised to this level.

2. While continuing to control lead pollution, actively support the development of new technology lead-acid batteries with a specific energy greater than 50 Wh/kg, a cycle life of 3000 times, and a price of less than 0.6 yuan/Wh.

3. Encourage the development of a new type of water electrolyte energy storage battery with a specific energy greater than 50 Wh/kg, a cycle life of 4000 times, a price less than 0.8 yuan/Wh, and an environmentally friendly production-recovery process.

Under the conditions of appropriate incoming and outgoing electricity prices, the storage power stations using the above-mentioned batteries are likely to achieve an operational effect of YCC (criterion of economic benefits of large-scale storage technology) with an index of 1.0, and have high safety guarantees.