Sungrow launches fully integrated C&I battery

China’s Sungrow has introduced its latest innovation—the PowerStack 255CS, a liquid-cooled battery energy storage system (BESS) designed specifically for commercial and industrial (C&I) applications. Unveiled at the Global Renewable Energy Summit 2025 (GRES2025) in Hefei, China, the system targets longstanding deployment challenges in the C&I sector, offering a compact and highly scalable solution.

The PowerStack 255CS integrates a PCS with a three-phase design, BMS, and EMS into a unified enclosure, significantly improving installation and operation. It features Sungrow’s innovative grid-forming technology, ensuring stability even in complex grid environments, as well as off-grid operation, supporting 100% unbalanced loads without the need for external transformers.

At the core of its technical offering is a maximum system efficiency rating of ≥98.5%, achieved through Sungrow’s proprietary silicon carbide (SiC) semiconductors and ultra-low magnetic-loss components. The system’s round-trip efficiency (RTE) exceeds 90%, bolstered by AI-driven thermal management that minimizes energy loss during charge and discharge cycles.

The PowerStack features intelligent liquid cooling, maintaining a cell temperature variance of less than 2.5°C— outperforming traditional air-cooled systems. This results in a projected operational life exceeding 12 years, even under harsh conditions ranging from –30°C to 50°C, with IP55-rated protection against dust and water.

Available in two configurations—257 kWh (2-hour discharge) and 514 kWh (4-hour discharge)—the system supports parallel operation of up to 25 units, with each delivering 125 kW of nominal power. Its compact footprint (e.g., 1.15m x 2.45m x 1.61m for the 2-hour model) makes it suitable for space-constrained urban and industrial environments.

According to Sungrow, the PowerStack 255CS offers exceptional versatility, applicable across established scenarios including standalone commercial and industrial energy storage systems (C&I ESS), PV and energy storage systems – supporting both AC and DC coupling, energy storage systems integrated with EV chargers (ESS & EV charger), and microgrids.

Sungrow has prioritized safety in the PowerStack’s design. Multi-stage fire suppression—including combustible gas detectors, aerosol extinguishers, and explosion vent panels—is paired with two-hour fire-resistant cabinets to mitigate thermal runaway.

For smart operations, the system leverages iSolarCloud, Sungrow’s proprietary digital platform, which offers real-time diagnostics, remote firmware updates, and predictive maintenance. Pre-installed components and automated commissioning reduce grid-connection timelines by up to 7.5 times, while also cutting on-site technician visits by 75%, according to the manufacturer.

Sungrow envisions the PowerStack 255CS enabling diversified revenue models, including energy arbitrage, frequency regulation, peak shaving, and emergency backup. Early commercial deployments—in a South African manufacturing plant (110 kW/225 kWh), Japan’s first zero-carbon highway service station (136 kW/202 kWh) and three projects in Spain —have reported significant power costs reductions and faster return on investment compared to conventional systems.

Dr Cao Wei, Sungrow’s general manager of C&I energy storage product line, told ESS News that there is a strong need for systems that “balance profitability with resilience” in the C&I market. “This product redefines what businesses can expect from energy storage, today and for the next decade,” he said, highlighting the system’s AI-driven optimization and modular scalability.

“We sincerely hope that in today’s market where products are becoming more alike to each other and policies are still not very stable, our customers can truly experience the safety of Sungrow’s products, the long-term benefits they will gain, and the high-standard service system we provide throughout the whole process, from design, manufacturing to installation and after-sales service.”

Looking ahead, Sungrow anticipates strong growth in the C&I storage market, fueled by soaring electricity prices, grid instability, and decarbonisation mandates. With 520 global service centres, the company says it is well-positioned to deliver long-term support and expand its global footprint.

Having already deployed over 1,000 C&I storage projects across the world, Sungrow is planning to offer PowerStack 255CS globally since this Q2, backed by commissioning support through certified partners.