On Wednesday, BYD Energy Storage announced it had signed a cooperation agreement with Portuguese renewable energy developer Greenvolt Power to jointly develop the Siedlce battery energy storage system (BESS) project in Poland. The project has a planned capacity of 600 MW / 2.4 GWh and, once completed, will become the largest battery energy storage project currently in development in Poland. According to BYD, the Siedlce project is scheduled to begin construction in the third quarter of 2026 and is expected to enter commercial operation by the end of 2027. BYD BESS Once operational, the facility will provide grid services including peak shaving, frequency regulation, and renewable energy integration, improving the Polish power system’s ability to absorb wind and solar generation. The project will adopt BYD’s latest Haohan energy storage system, which is equipped with a 2,710 Ah proprietary “Blade” battery designed for stationary storage applications. A single storage unit offers up to 14.5 MWh capacity, with an equivalent 10 MWh per 20-foot standard container system configuration. Compared with conventional solutions, higher per-unit capacity reduces the number of required containers and land footprint while lowering overall construction costs. This marks a repeat collaboration between BYD Energy Storage and Greenvolt Power in Poland. The two parties have previously jointly developed projects in the country totaling 1.6 GWh. On June 13, a separate project in Hungary developed by Greenvolt Power entered commercial operation. The facility, with a scale of 99.8 MW / 288.6 MWh, is the largest battery storage project in Hungary to date, with BYD supplying its MC Cube BESS system. BYD Energy Storage at TSEE 2026 At TSEE 2026, BYD Energy Storage also unveiled its Residential Energy Ecosystem targeting the European household market, alongside its next-generation Battery-Box Mega home storage product. The company additionally showcased its Haohan utility-scale storage system, next-gen GC Flux PCS, and GC Master EMS, further extending its product portfolio from residential to grid-scale applications. As renewable energy penetration continues to rise across Europe, energy storage has become a critical infrastructure component for maintaining grid stability. BYD Residential Energy Ecosystem Markets including Poland, Germany, and Hungary are accelerating deployment of storage capacity to manage volatility from renewable generation. For BYD, the energy storage business is increasingly emerging as a key growth pillar beyond its electric vehicle operations. Leveraging its Blade battery tech and system integration capabilities, the company has deployed large-scale storage projects in more than 110 countries and regions worldwide.