Key takeaways from ESIE 2026 (Pt 1): China storage enters a more disciplined growth phase

At ESIE 2026, the 14th Energy Storage International Summit and Exhibition in Beijing, scale was not in short supply. The show brought together more than 800 companies, featured more than 150 product launches, and made clear that China’s storage industry is far beyond its early expansion phase.

The industry is instead moving into a more selective stage, where the key questions are less about whether storage will grow, but more about which technologies, architectures, and application scenarios will define the next round of value creation.

One immediate impression from the exhibition floor was that the industry looked less euphoric than in previous years, but more grounded. Vendors were still pushing claims on safety, cost and performance, yet the stronger signal was convergence. Cell formats are getting bigger, grid-forming power conversion is more popular, and AI data center applications are emerging as one of the clearest new demand anchors.

Large-format cells have moved from experiment to mainstream

If one product theme dominated the battery halls, it was the normalization of 500 Ah-plus formats. In particular, 588 Ah-class cells appeared to be the new center of gravity, with CATL (which holds slightly smaller size of 587 Ah), CALB, and REPT all using that range to balance energy density, cycle life, and system integration economics. 

CATL’s 587 Ah storage cell, already in large-scale commercialization with cumulative shipments above 5 GWh, showed how quickly this format has moved into the mainstream. CALB, meanwhile, used ESIE 2026 to reinforce its long-cycle positioning with 392 Ah, 588 Ah, and 661 Ah products built around 15,000-cycle performance and a 25-year calendar life.

At the upper end, some pushed far beyond the new standard. Envision presented a 790 Ah prismatic wound cell with energy density above 440 Wh/L and cycle life above 15,000 cycles, while BYD showcased a 2,710 Ah blade battery for storage and paired it with its Haohan system architecture. These launches suggest the industry is still testing the upper boundary of cell enlargement, even as 588 Ah becomes the practical mainstream.

Grid-forming PCS is becoming a baseline requirement rather than a premium option

Another strong signal from the show was the rapid normalization of grid-forming capabilities. What was once treated as a specialized feature is now being presented as core infrastructure for large-scale storage. The shift has been gradual until now, where storage is now increasingly an active grid-support asset capable of voltage and frequency stabilization.

Kehua Digital Energy placed its grid-forming and grid-following integrated booster stations at the center of its display, highlighting highly integrated 6.25 MW and 6.9 MW platforms designed to reduce footprint and civil works. Hoypower promoted a 1,725 kW-rated grid-forming PCS with black-start capability, frequency support, and weak-grid adaptability. Sineng Electric also emphasized grid-forming PCS and larger integrated conversion stations, underscoring how central the category has become.

What matters here is not just product count but cost normalization. According to observations on the floor and in discussions, the earlier 10%-15% premium over conventional systems has largely disappeared. That makes grid-forming less of a niche premium and more of a competitive necessity. The caveat, however, is that the show also hinted at growing “false labeling,” with some vendors using the term without demonstrating full off-grid or short-circuit capabilities. In other words, grid-forming has become mainstream enough to attract imitation.

AI data center storage is emerging as the most compelling new demand story

ESIE 2026 also made clear that AI data center (AIDC) storage has become a concrete fact, rather than fashionable. Nearly every major integrator seemed to have an “AIDC + storage” narrative, reflecting a broader market recognition that AI infrastructure places unusual demands on power systems, including high power density, rapid fluctuations, and very high reliability requirements. Conventional grid supply alone is now insufficient for that load profile.

Envision offered one of the most complete narratives, linking dedicated large cells, sodium-ion development and full-stack energy management to an end-to-end solution for AI-era power supply. Its reference project with Tencent in Chifeng, Inner Mongolia, was described as the world’s first 100% renewable-powered data center, with more than 40% lower integrated energy costs and annual carbon reductions of 180,000 tons.

Other exhibitors focused more narrowly on the power-quality and backup requirements of the segment. Guangzhou Great Power introduced its Hanhai 85 Ah energy storage battery cell for data center use, designed for 10C discharge and millisecond response. Shuangdeng, meanwhile, highlighted a semi-solid-state 8 MWh system and dedicated AIDC products aimed at intrinsic safety and fast response, while NARADA promoted a new backup platform with single-cabinet power above 600 kW and very high pulse capability.

The result is that the hyperscaler data center is beginning to shape product design itself, from high-rate cells to safety chemistry choices and DC-side architectures. ESIE 2026 did not suggest that China’s storage sector has solved its deeper challenges. Price pressure remains intense, and the gap between inquiry volume and real orders is still a concern. But the show did point to a more mature industry logic.

Bigger cells are no longer a novelty, grid-forming is becoming standard practice, and AI-linked demand is giving suppliers a clearer next market. The sector still faces margin stress, but it now looks more technically anchored than it did a year ago.