Sungrow’s PowerStack 255CS series ESS with up to 2 hours and 4 hours backup configurations were displayed during the event for the South African C&I market. (Photo Credit: Sungrow) 
Technology

Sungrow Showcases C&I ESSs For South Africa

The promoted products comprised both AC- and DC-coupled configurations, offering a variety of power and storage options

Rajarshi Sengupta

  • Sungrow’s PowerStack 255CS series ESS supports an AC-coupled configuration 

  • It features an AC Block design, which combines battery units and PCS in a single enclosure or cabinet 

  • The company’s DC-coupled ESS reduces intermediate conversion losses and accommodates additional PV capacities compared to AC-coupled alternatives 

Sungrow, a global player in PV inverters and energy storage systems (ESS), recently showcased its C&I product range targeting the South African market during the C&I Summit in Johannesburg. 

Among the displayed products were its AC-coupled and DC-coupled ESSs for 3-phase low-voltage (440 V) applications. In the former category, the company promoted PowerStack 255CS, which supports the revamping of an existing PV installation. Equipped with 314 Ah battery cells and a 125 kW power conversion system (PCS), it has a rated power output of up to 125 kW and stores or discharges up to 257 kWh of energy for up to 2 hours at nominal charging and discharging rates. Its higher capacity variant (125 kW/514 kWh) extends the backup duration to up to 4 hours. The company states that its AC Block design combines battery units and PCS in a single enclosure or cabinet. It helps achieve a round-trip efficiency (RTE) of up to 90% due to reduced conversion losses relative to standard alternatives with separate ESS and PCS (outside container or battery enclosure). In addition, it supports unbalanced 1-phase loads (like lighting) that are not evenly distributed among the 3 phases and eliminates the need for an isolation transformer as a safety layer. This attribute helps reduce overall system costs. In terms of operational efficiency and safety, this system adopts a cooling mechanism based on a circulating cooling medium. 

For the DC-coupled category, the company’s press release didn’t disclose the product series or model name; however, it shared key advantages of this system. This system directly connects the PV array and battery units to the inverter’s DC side and supports greenfield solar-plus-storage installations in multiple layout configurations. Compared to its AC-coupled counterparts, it reduces conversion losses and accommodates additional PV capacity. On the safety front, it is equipped with a pressure relief mechanism that prevents the battery pack lids from popping off during abnormal internal pressure.