Long-term energy storage has been upgraded from "auxiliary" to "essential for the power grid"

This shift in the demand side is also driving the upgrade of technical specifications on the supply side. One notable signal is that since this year, multiple bidding projects of state-owned enterprises and central enterprises have included super-large battery cell single-row packages - this is not an accident but a direct mapping of the "longer duration, larger capacity" hard requirements of long-term energy storage on the procurement side.

For example, the 7GWh battery cell special frame procurement bidding of China Energy Engineering Group's Zhongchuan Technology, for the first time set 500+Ah large battery cells in an independent package; the 4GWh energy storage system frame procurement of China Huadian, set a 1GWh segment separately, clearly stating that the battery cell capacity should be higher than 450Ah. Additionally, Jiangxi Lixing Energy Storage Technology Co., Ltd. purchased a total of 6GWh of 587/588Ah large-capacity lithium iron phosphate energy storage battery cells in June this year.

At the policy level, the series of "Fifteen-Year Plan" energy plans released by the National Development and Reform Commission and the National Energy Administration have drawn a clear growth curve for the energy storage industry. The recently released "Fifteen-Year Plan for the Construction of New Power Systems" (referred to as the "Plan") states that by 2030, the national scale of new energy storage should reach 300GW, compared with 136GW at the end of 2025, an additional approximately 160GW within five years. This means that during the "Fifteen-Year Plan" period, the average annual new installation of new energy storage will maintain a high level of over 30GW. The Plan also clearly states that during the "Fifteen-Year Plan" period, the national additional independent new energy storage on the grid side that can undertake peak load supply will be approximately 80GW, and the equivalent peak duration is expected to reach 4 hours. By 2030, the independent new energy storage on the grid side that can undertake peak load supply will reach 140GW.

The industry generally believes that when the proportion of new energy power generation reaches 15%-20%, the demand for 4 hours or more long-term energy storage will become a necessity. According to the data of the National Energy Administration, in 2025, the proportion of wind power and solar power generation in the total social power generation reached 22%, having substantially crossed the above critical range. At the industrial level, by the end of 2025, the installed capacity of 4 hours or more long-term new energy storage projects that have been built and put into operation in the country has reached 27.6%, an increase of approximately 12 percentage points compared to the end of 2024.

Furthermore, in July this year, two energy storage safety regulations were implemented simultaneously: one is the "General Safety Specifications for Grid-connected Energy Storage Systems and Standalone Energy Storage Systems", which sets quantitative safety requirements for heat runaway prevention, fault isolation, and system testing, and limits the total number of battery cells in series in a single cluster; the other is the "No. 41 Order" jointly issued by the National Development and Reform Commission and the National Energy Administration, which clearly states that if the energy storage power station connected to a 220-kilovolt or above grid does not meet the five major grid connection capabilities, it will be uniformly judged as a major hazard.

Industry analysts believe that although these two documents do not directly limit the battery cell capacity, all quantitative safety indicators impose constraints on the small-capacity multi-series stacking scheme. 500+Ah large-capacity battery cells are currently the most easily compliant and feasible technical route at this stage.

And this is not unique to China. Institutions predict that in 2027, the competition for long-term energy storage will shift from 4-6 hours to 8-10 hours. Europe has already released the demand for 8 hours or more on the grid side, and the United States' AI data centers have driven the demand for 10 hours or more backup power and off-grid. And around this "long-term energy storage" competition, the production capacity layout and technology route competition of battery manufacturers have entered the deep water zone.