The 33rd China International Exhibition on Electric Power Equipment and Technology
Shanghai International Energy Storage Technology Application Expo / Hydrogen Energy Expo
A Battery Energy Storage System (BESS) is a large-scale energy storage installation that uses rechargeable batteries — most commonly lithium iron phosphate (LFP) chemistry in China — to store electrical energy and release it on demand. BESS provides a range of grid services: frequency regulation (responding within milliseconds to grid frequency deviations); peak shaving (charging during low-demand periods and discharging during peak demand to reduce peak capacity requirements); renewable energy integration (storing surplus solar or wind generation and releasing it when generation is insufficient); voltage support; and backup power. China is the world's largest BESS market, with domestic manufacturers CATL, BYD, and SUNGROW supplying the majority of global utility-scale BESS installations. The 14th Five-Year Plan targets 30 GW of new energy storage capacity by 2025.
5 Key Questions About Battery Energy Storage System (BESS)
Lithium iron phosphate (LFP) is the dominant chemistry for utility-scale BESS in China, offering good cycle life (3,000–6,000 cycles), thermal stability, and competitive cost. Nickel manganese cobalt (NMC) lithium batteries offer higher energy density but lower cycle life and higher cost. Sodium-ion batteries are an emerging alternative using abundant sodium instead of lithium, with lower cost potential and better low-temperature performance. Flow batteries (vanadium redox, zinc-bromine) offer independent scaling of power and energy capacity and very long cycle life, making them suitable for long-duration storage applications. Lead-acid batteries are used for smaller backup power applications.
BESS can provide multiple grid services simultaneously through co-optimisation: primary frequency response (within 200 ms); secondary frequency regulation (AGC participation); peak demand reduction; renewable energy time-shifting; transmission and distribution congestion relief; voltage support through reactive power injection; black start capability; and backup power for critical loads. The ability to stack multiple revenue streams — frequency regulation plus peak shaving plus capacity market payments — is essential for BESS project economics.
Front-of-meter (FTM) BESS is connected directly to the transmission or distribution grid and operated by utilities or independent power producers to provide grid services and participate in electricity markets. Behind-the-meter (BTM) BESS is installed on the customer side of the electricity meter, primarily to reduce demand charges, provide backup power, and optimise self-consumption of rooftop solar. BTM BESS for commercial and industrial (C&I) customers is a rapidly growing market in China, driven by time-of-use tariff structures and demand charge management.
Large-scale BESS requires comprehensive safety systems to manage the risk of thermal runaway — a self-sustaining exothermic reaction that can lead to fire and explosion. Safety systems include: cell-level and module-level battery management systems (BMS) monitoring temperature, voltage, and current; fire detection and suppression systems (typically aerosol or heptafluoropropane); thermal management systems maintaining cells within safe temperature ranges; gas detection systems monitoring for hydrogen and other combustion products; and structural containment to prevent fire spread between battery modules. China's GB/T 36276 standard specifies safety requirements for lithium battery energy storage systems.
The levelised cost of storage (LCOS) for utility-scale LFP BESS in China has fallen dramatically, from over RMB 2/kWh in 2015 to approximately RMB 0.4–0.6/kWh in 2024, driven by falling battery cell prices (below RMB 500/kWh for LFP cells), improved system integration, and longer cycle life. Further cost reductions are expected as manufacturing scale increases and next-generation battery technologies mature. At current costs, BESS is economically competitive for frequency regulation and peak shaving applications in China's electricity market.
Key Takeaways
Reactors are essential components for current limiting, harmonic filtering, and reactive power compensation in power systems. As grids incorporate more power electronics for renewable integration and HVDC transmission, reactor demand continues to grow. EP Shanghai connects reactor manufacturers with utility and industrial buyers.
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