China’s ‘super power bank’ reaches key construction milestone

China’s Lianghekou Dam project has reached a significant construction milestone in developing the world’s largest hybrid pumped hydro storage facility. Excavation of the underground powerhouse, dubbed the “power heart,” located nearly 500 meters beneath the mountain, has been completed, and construction of the downstream reservoir has begun. This facility, situated at an elevation of 3,000 meters on the Western Sichuan plateau, includes two reservoirs and four 300 MW units, combining conventional hydropower with pumped storage to achieve a total capacity of 4.2 GW. Pumped hydro storage works by using excess renewable energy to pump water from a lower to an upper reservoir, storing energy as potential energy. When demand rises, water flows back downhill through turbines to generate electricity, enabling grid balancing and mitigating the intermittency of wind and solar power. Unlike conventional hydropower, pumped storage allows for reusable water cycling, supporting year-round operation. The Lianghekou facility is designed to integrate with 7 GW of renewable energy