According to the State Grid Corporation of China, as of July 7, the peak electricity load of Jiangsu’s power grid, affected by the prolonged extreme heat, has hit a record high for the third time this year, reaching 152 gigawatts. On July 6, under the unified command of the State Grid Jiangsu Electric Power Corporation Limited Power Dispatching Center, 93 new-type energy storage stations across the province discharged electricity into the grid during evening peak hours. The maximum discharge power reached 7.14 gigawatts, marking China’s largest-scale unified deployment of new-type energy storage to date.

New-type energy storage systems are often compared to super power banks. They can discharge during peak hours to help stabilize the grid and recharge during off-peak hours to absorb renewable energy. On the evening of June 6, 64 grid-side and 29 power-source-side energy storage stations, with a total capacity of 7.248 gigawatts, participated in centralized discharging to satisfy the peak electricity demand, and the actual maximum dispatching scale reached 7.14 gigawatts. It set a new record in terms of the scale after the centralized deployment of 4.55 gigawatts last summer, a year-on-year increase of 56.9%. During this operation, the State Grid Jiangsu Electric Power used a new-generation dispatching system to simultaneously send a discharge command to more than seven gigawatts of energy storage facilities during peak hours, which could satisfy one hour’s power consumption for about 48 million households at the maximum.  

Though it may seem simple, the timing of charging and discharging must be carefully selected. Discharging needs to not only meet urban power consumption demand but also ensure the profitability of energy storage projects. “In terms of the distribution, most of Jiangsu’s energy storage facilities are located in North Jiangsu, while power is mainly consumed by South Jiangsu. Moreover, the peak demand appears during the day in South Jiangsu, while that emerges at night in North Jiangsu. Therefore, energy storage can act as a ‘time-space regulator’ to balance supply and demand.” According to Qiu Chenguang, Director for Dispatch and Operation at the State Grid Jiangsu Electric Power Corporation Limited Power Dispatching Center, Jiangsu has an installed new-type energy storage capacity of 7.616 gigawatts, ranking fourth nationwide, involving various forms like electrochemical energy storage and salt-cavern compressed air energy storage.