Sungrow pitched its DC-coupled storage solution, 1+X inverter plus PowerTitan 3.0 storage, for Australia’s utility market
It can store excess PV energy faster within a short window of low-tariff periods compared to its AC-coupled peers
It can discharge for up to 8 hours, particularly during nighttime with peak load demand and high tariff
PV and battery energy storage systems (BESS) provider Sungrow promoted its utility-scale DC-coupled solution at the PV & ESS Summit in Sydney.
With the growing penetration of renewable energy in the country’s grid, tariffs often cross the negative threshold, particularly during daytime with both solar and wind generation. This, inadvertently, forces grid operators to curtail excess solar generation to maintain grid health, resulting in losses for solar developers. It also makes the country’s National Electricity Market (NEM), whether it is for the day-ahead or spot market, volatile.
Against this backdrop, Sungrow pitched its DC-coupled solution, which combines the 1+X ‘modular’ inverter with its PowerTitan 3.0 storage solution.
On the hardware side, the inverter, with an IGBT-based power stack (DC/AC converter), features a replaceable modular design compared to traditional counterparts. This solution places multiple inverters side-by-side and connects them to the PV arrays with up to 200% oversizing (DC/AC), maximizing solar harvesting. Furthermore, instead of using an intermediate bidirectional power conversion system (PCS), these inverters couple directly to the storage solution. This coupling architecture eliminates the medium voltage (MV) transformer, resulting in higher conversion efficiency (charging/discharging) compared to AC-coupled peers. Together, these minimize round-trip losses of the system. While not quantifying the gain, rated power, or storage capacity, the company says this solution supports continuous discharge for up to 8 hours.
In terms of operation, it stores PV generation during negative, low-tariff, or curtailment periods and discharges it during high-tariff periods. Its DC-coupling configuration supports fast charging during windows of low tariffs, the company added. These complex operations are monitored and controlled in real time by the company’s energy management system, PV-ESS Synergy Management System. In addition to economic benefits, this electricity arbitrage helps maintain grid stability, albeit passively.
Recently, Sungrow also pitched this solution for the European utility market.