Overview
Commercial and industrial (C&I) energy storage systems are relatively smaller in capacity and have simpler system functions.
C&I storage requires lower system control complexity than utility-scale storage; some PCS products also incorporate BMS functions.
For EMS, C&I storage typically only requires scheduling of charge and discharge times to manage energy; functional requirements are lower than for utility-scale systems.
Battery
C&I energy storage has relatively low requirements for response time. Due to cost, cycle life, and response-time trade-offs, energy-type batteries are typically used.
Utility-scale frequency-regulation storage uses power-type batteries. Although most utility-scale systems still use energy-type batteries, frequency-regulation applications require higher cycle life and faster response times, so power-type batteries are often selected.
BMS
For C&I systems, the battery BMS provides protections for the battery pack, including overcharge, overdischarge, overcurrent, overtemperature, undertemperature, short circuit, and current limiting.
It provides voltage balancing during charging and supports parameter configuration and data monitoring via backend software. It communicates with various PCS types to jointly enable intelligent management of the storage system.
Utility-scale BMS performs hierarchical unified management with a more complex structure. It calculates and analyzes battery parameters and operating states across layers and levels to implement effective balancing, alarms, and protection. This ensures equalized output among modules and achieves optimal operation and maximum runtime.
The BMS provides accurate and effective battery management information, and battery balancing management greatly improves energy utilization and optimizes load characteristics. At the same time, it maximizes battery lifespan and ensures system stability, safety, and reliability.
PCS
C&I PCS functions are relatively simple and more adaptable. They are based on bidirectional conversion, are compact, and can be flexibly scaled according to needs, making integration with battery systems easier.
They typically support an ultra-wide voltage range of 150–750 V to meet various series and parallel battery configurations, and can be compatible with various types of PV inverters.
Utility-scale PCS have wider DC-side voltage capability and can operate at full load at 1500 V. Beyond basic converter functions, they provide grid-support capabilities such as primary frequency response and fast dispatch of source-grid-load, with strong grid adaptability and fast power response (<30 ms).
EMS
C&I systems generally do not accept grid dispatch, so EMS functionality is basic and focused on local energy management:
- Support battery balancing management to ensure operational safety.
- Support millisecond-level response to enable integrated management and centralized control of storage subsystem equipment.
Utility-scale systems must accept grid dispatch, so EMS requirements are higher. In addition to basic energy management, EMS must:
- Provide grid-dispatch interfaces and energy management functions for microgrid systems.
- Support multiple communication protocols and standard power-dispatch interfaces.
- Manage and monitor energy shifting, microgrid operation, and frequency-regulation applications.
- Support monitoring of multi-energy complementary systems across source, grid, load, and storage.
Core Component: Energy Storage Converter (PCS)
The core component of energy storage is the PCS. The PCS is the key device between the storage unit and the grid, controlling battery charge and discharge, performing AC/DC conversion, and, in islanded operation, directly supplying AC loads.
PCS are categorized by application into residential, commercial, centralized, and utility-scale types. Centralized storage systems have relatively larger installed capacity and represent the largest market demand.
Energy storage converters have become a revenue growth point. According to statistics, among 11 major PCS companies in the Chinese market, 10 reported revenue increases in 22Q3, representing over 90%.
Trends in C&I Energy Storage
Most companies adopt an "intelligent + modular" design approach:
- Intelligent refers to data acquisition, safety control, and BMS/EMS functions. It uses algorithms and related technologies combined with traditional power-grid and energy-system control and protection for intelligent management.
- Modular refers to designing energy modules as independent hardware and software units that can be freely combined and flexibly deployed for different applications. The C&I storage market is characterized by diverse and variable user needs, so product design must account for multi-scenario adaptability.
Refined Control Is a Growing Requirement
Compared with large-scale storage, C&I storage demands higher complexity in refined control strategies and algorithms. As power markets open and application scenarios diversify, software and system control capability will become a core competitive factor for C&I energy storage providers.
