Recently, the 601MWh large-scale energy storage project, developed jointly by Eastern Europe’s leading company Solarpro Holding and CATL, was successfully connected to the grid and began commercial operation in Bulgaria. Dubbed locally as a “super green energy block,” the project has effectively increased Bulgaria’s total installed energy storage capacity by approximately 15% following its commissioning, significantly raising the share of wind and solar power in the country’s energy mix. Based on this collaboration, Solarpro Holding and CATL have reached a long-term cooperation intent and plan to further expand the scale of energy storage projects over the next two years. 601MWh large-scale energy storage project officially operational The project adopts CATL’s self-developed Tianheng energy storage system. According to the company, this is the industry’s first 6MWh-class zero-degradation product. By integrating 565Ah LFP battery cells, the system achieves an areal energy density exceeding 407 kWh/m². For the same 600MWh capacity, it saves approximately 20% of floor space compared to conventional solutions. In terms of safety, the system achieves zero capacity degradation in its first year, while its internal rate of return (IRR) is increased by 1.13 percentage points. Additionally, the system features multi-layer fire protection and high-level insulation design, offering corrosion resistance and seismic resilience for long-term stable operation even in extreme environments. Meanwhile, its auxiliary power consumption is kept below 2.5%. Tianheng Energy Storage System In fact, CATL has been moving very frequently in the European market recently. Just as the Bulgaria project went live, CATL signed a strategic cooperation agreement with Spanish renewable energy company Grenergy on May 21, agreeing to supply a total of 1.5GWh of energy storage equipment for two projects in Spain. Industry analysts point out that the Bulgaria project marks an important transition for CATL – from exporting products to exporting technical standards. As EU-China green cooperation deepens and the EU’s renewable energy targets rise, energy storage going global will become a key focus for Chinese new energy companies. According to SNE Research data, CATL’s energy storage battery shipments reached 121GWh in 2025, ranking first globally for five consecutive years (2021–2025) with a global market share of 30.4%, and has been deployed in approximately 2,300 projects worldwide.