Project Background
This project is deployed at a light industrial park with rooftop PV installation. The site includes offices and small workshops with stable daytime loads. The client aims to maximize PV self-consumption and cut grid electricity bills. Meanwhile, short-duration grid outages require backup power for critical loads including central control, security and lighting. The customer selects our 125kW/241kWh PV-ESS all-in-one cabinet with DC-coupled topology.
Core Customer Pain Points
Rooftop PV generates excess power during sunny hours, which has to be curtailed due to limited on-site consumption.
Occasional short grid outages interrupt control, security and lighting systems, bringing operational risks.
Conventional separated PV and ESS systems require multiple independent units, resulting in heavy wiring work and complicated maintenance.
Limited space inside the park's power distribution room; customer needs to reduce footprint of power equipment.
System Configuration & Product Selection
1 set of 125kW/241kWh PV-ESS all-in-one cabinet, DC-coupled topology
The cabinet integrates DC-DC converter, bi-directional PCS, LFP battery pack, BMS, thermal management and aerosol fire suppression. Rated power:125kW, usable capacity:241kWh. Rooftop PV connects directly to the DC port of the cabinet; AC output connects to the park's distribution bus. Auxiliary equipment: rooftop PV modules, DC combiner box, critical load transfer cabinet, cloud EMS platform.
Core Control Strategy
PV self-consumption priority: Solar power feeds park loads first. Surplus DC power charges the battery pack to reduce PV curtailment.
Power quality optimization: Smooth PV power fluctuation and stabilize voltage at point of grid connection.
Off-grid backup capability: In case of grid failure, the PCS switches to grid-forming off-grid mode automatically to supply critical loads. When grid recovers, the system seamlessly returns to grid-tied mode.
Peak-valley arbitrage: Charge from grid during low tariff valley hours and discharge at peak hours to boost revenue. Cloud EMS monitors operating status, SOC and alarms remotely.
On-site Installation Challenges & Our Solutions
Challenge1: Tight project timeline; client wants shorter on-site installation and commissioning Solution: The 125kW/241kWh all-in-one cabinet is fully assembled and factory-tested before delivery. On-site work only involves foundation installation and cable connection. It greatly reduces wiring and commissioning work to shorten project delivery.
Challenge2: Require seamless grid-tied/off-grid switching, while old distribution lacks backup transfer circuit Solution: We supply matched load transfer cabinet paired with the grid-forming PCS inside the all-in-one cabinet. The EMS triggers millisecond-level switching during grid faults to protect security & control loads, without massive rework of original main power lines.
Challenge3: Dusty outdoor environment with large day-night temperature swing; separate units suffer high failure rate and heavy maintenance Solution: IP55 rated integrated cabinet with built-in thermal control and fire protection. Enclosed structure blocks dust and stabilizes battery temperature, slowing battery degradation and lowering routine maintenance.
Challenge4: Multiple discrete devices often have communication compatibility issues, making system coordination difficult Solution: DC-DC, PCS and BMS are integrated in one cabinet with native internal communication. No cross-brand protocol debugging required on site, improving overall system reliability.
Project Outcomes & Benefits
Higher rooftop PV self-consumption rate and less solar curtailment, lowering daily grid electricity cost for the park.
Short-time off-grid backup function guarantees power supply for central control, security and lighting during grid blackouts, improving power safety.
DC-coupled all-in-one design reduces total equipment count and footprint, cutting civil, cabling and construction costs.
Unified BMS and local controller ensure stable communication. Cloud EMS enables remote monitoring for simple maintenance.
125KW 241kWh Battery Energy Storage System Cabinet
The BESS 125KW 241kWh Lithium Battery Energy Storage Cabinet is a high-power, large-capacity integrated energy storage solution engineered for medium-to-large commercial, industrial, and utility-scale applications. It integrates a 125kW high-performance bidirectional inverter, a 241kWh lithium iron phosphate (LiFePO4) battery bank, and a full-featured intelligent energy management system (EMS) into a modular cabinet design. This system enables efficient renewable energy storage, peak shaving, load shifting, grid frequency regulation, and emergency backup power supply. Ideal for large factories, shopping malls, industrial parks, utility-scale solar/wind farms, and microgrids, it enhances energy independence, reduces high grid demand charges, and supports the stable integration of high-penetration renewable energy into the grid.