The No. 2 unit of the second-phase Jintan salt cavern compressed air energy storage (CAES) project in Jintan district, Changzhou, Jiangsu province, has completed full-unit startup, according to Power Construction Corporation of China (Power China), which participated in the construction. The project is the world's largest salt cavern CAES station by single-unit capacity, total capacity and overall efficiency, with two 350 MW non-supplementary-fired CAES units planned, 8 hours of storage and 4 hours of generation, an energy conversion efficiency of over 70%, and a single charge storing 2.8 million kWh. Core equipment will be 100% domestically produced once operational.