On February 22nd, on the 3000-meter-high plateau in Western Sichuan, the Yalong River Lianghekou Pumped Storage Power Station, the world's largest and highest-altitude hybrid pumped storage power station under construction, achieved two critical breakthroughs: the successful completion of underground powerhouse excavation and the smooth first concrete pour for the dam of the Yagen Level I hydropower station, which will serve as the lower reservoir.
The Lianghekou project is the world's largest hybrid pumpeded storage initiative. It will utilize the Lianghekou Reservoir, Sichuan Province's largest "super reservoir," as the upper reservoir and the Yagen Level I hydropower station reservoir as the lower reservoir. The station will be equipped with four 300,000-kilowatt reversible units. These will operate in conjunction with the 3 million kilowatts of conventional generating units at the Lianghekou Hydropower Station, resulting in a total installed capacity of 4.2 million kilowatts. Once operational, the facility will possess the dual functions of generating power from natural river flow and providing pumped storage for energy regulation.
The construction of the project's underground powerhouse, often described as the plant's "power heart," is a core component of the entire endeavor. Buried approximately 500 meters deep within the mountain, the powerhouse stretches nearly 200 meters in length and stands 60 meters high. Facing severe challenges inherent to high-altitude construction, the builders relied on a self-developed intelligent construction management platform. This system integrated multiple smart technologies, including BIM modeling, 3D laser scanning, intelligent rock drilling, intelligent blasting, and intelligent ventilation. The construction team employed a "pre-splitting blasting plus smooth blasting" technique, advancing the excavation work in layered sections.
During the recent Spring Festival holiday, over 500 construction workers remained on site, capitalizing on the dry season's "golden window" for construction. Operations continued 24 hours a day with shift work. The project deployed the first domestically produced intelligent unmanned rock drilling jumbo, achieving drilling accuracy at the centimeter level. This "unmanned intelligent construction" model not only increased construction efficiency by over 30% but also significantly reduced labor intensity and safety risks, contributing to the completion of the powerhouse excavation three months ahead of schedule.
The completion of the underground excavation marks the conclusion of the main civil excavation phase. The project now transitions to the electromechanical equipment installation stage, providing strong support for the goal of completing the Lianghekou clean energy demonstration zone—which integrates hydropower, wind, solar, storage, hydrogen, and computing—by 2028.
Concurrently, the first concrete was poured for the dam of the Yagen Level I hydropower station. This station is the second cascade in the "one reservoir, seven levels" development plan for the middle reaches of the Yalong River. With a total installed capacity of 300,000 kilowatts, it features the widest single-section gate dam in China, with the longest individual dam section measuring 47 meters, representing a significant breakthrough in the design and construction of large hydropower projects.
Upon completion, the Yagen Level I station will serve as a re-regulating facility for the Lianghekou Hydropower Station while also functioning as the lower reservoir for the Lianghekou pumped storage plant, making it a key project within the clean energy demonstration zone.
The innovatively designed ultra-wide gate dam departs from the conventional pattern of independent sections for spillway gates in hydropower projects. This design transforms the spillway gate base slab into an extremely rigid "massive rock," significantly enhancing the project's earthquake resistance. However, challenges such as low winter temperatures, large temperature variations, and complex aggregate properties on the plateau made crack prevention during the concrete pouring for the ultra-wide single dam section exceptionally difficult, ranking among the most challenging tasks of its kind globally.
To address this issue, the construction team created a constant temperature and humidity "growth environment" for the concrete. They optimized the concrete mix to enhance internal frost resistance and durability from within—akin to putting "thermal underwear" on it—and established a comprehensive temperature control defense system, innovatively adopting methods like steam curing.
During the Spring Festival, more than 600 construction personnel remained on site, enabling the first concrete pour for the dam to commence on schedule. This milestone signifies the official start of the main structural engineering phase for the Yagen Level I hydropower station.