GSL ENERGY showcased its BESS-261K series C&I ESS with a rated full-load power of 125 kVA and a storage capacity of up to 261 kWh
The company also displayed its 125 kVA/418 kWh ESS with higher storage capacity at the same full-load rating
These products can perform peak shaving, valley filling, emergency backup, and participate in energy arbitrage and VPP functions
SHENZHEN GSL ENERGY TECH Co., Ltd., a new name in the energy storage system (ESS) segment, brought two new commercial & industrial (C&I) ESSs to Intersolar Europe 2026. The company says these systems provide resilience against volatile tariff rates and optimize electricity costs while generating passive revenue.
The BESS-261K series ESS is rated at a full-load power of 125 kVA, with a corresponding storage capacity of 261 kWh, in a 1,300 × 1,320 × 2,380 mm cabinet. Another ESS, from the BESS-125K418 series, accommodates a higher storage capacity of up to 418 kWh in a slightly smaller cabinet of 1,240 × 1,320 × 2,380 mm, while maintaining the same rated full-load power. Both models use 52.25 kWh lithium-iron-phosphate (LFP) battery packs; however, the former stacks 5 packs on top of one another while the latter mounts 8 packs.
Both storage systems are equipped with Deye’s 125 kVA hybrid inverter (3-phase), which DC-couples the storage and an on-site PV array with the grid. Here, the PV capacity and battery connect directly to the inverter's common DC busbar, enabling higher PV harvesting and reduced storage power loss compared to AC-coupling. Featuring DC/AC oversizing, these inverters receive maximum possible PV power throughout the day, which is inverted to AC power to feed captive C&I loads on priority. When generation exceeds demand, the excess is diverted to storage, preventing export at uncertain grid prices and maximizing PV self-consumption.
For resilience against an unforeseen grid outage, these inverters switch to off-grid mode within milliseconds and deliver full-load power until the battery cut-off voltage is reached. In addition to ensuring uninterrupted C&I load operations, they can deliver overload capacity for a few milliseconds to cater to the high starting current of inductive loads, boosting resilience. For example, the 125 kW/418 kWh ESS’s inverter is rated to deliver up to 160% overload capacity for up to 200 ms in off-grid mode.
The storage systems have an integrated energy management system (EMS) with built-in algorithms to support different grid-interactive energy management services. When C&I demand exceeds the scheduled daily load curve, the EMS commands the storage to discharge, helping flatten the demand curve while preventing higher-priced spot purchases from the power market. The batteries charge as soon as demand and the grid tariff drop, a function known as valley filling, while the former is called peak shaving. This intelligent battery charging/discharging optimizes consumers’ electricity costs. These systems can also participate in grid-side electricity arbitrage by discharging at high spot prices and charging at low spot prices. Furthermore, these ESSs can act as a dispatchable power source by participating in virtual power plant (VPP) aggregation programs with pre-fixed power purchase rates. These functions generate revenue for the consumers, albeit passively.
The capacity can be expanded to up to 4 MW/8.35 MWh by connecting up to 32 battery cabinets, each with 125 kW/261 kWh capacity, in parallel. The 125 kW/418 kWh version allows parallel connection of up to 10 units for a total capacity of 1.25 MW/4.18 MWh.
