The Lianghekou hybrid pumped storage hydropower station marked two milestones on Sunday, completing excavation of its underground powerhouse and beginning concrete pouring for its downstream reservoir, bringing the mega clean energy project in Sichuan Province closer to completion.

Located on the Western Sichuan Plateau at an altitude of 3,000 meters, the facility uses the Lianghekou Reservoir, the province's largest, as its upper reservoir and the Yagen Level 1 Hydropower Station reservoir as its lower reservoir. It is equipped with four reversible units of 300,000 kilowatts each, operating jointly with the 3 million kilowatts conventional units of the Lianghekou project to reach a total installed capacity of 4.2 million kilowatts.

Once completed, the plant will combine natural runoff power generation with bidirectional regulation through pumped storage.

The underground powerhouse, described as the project's "power heart," is buried about 500 meters beneath the mountain. Stretching nearly 200 meters in length and 60 meters in height, it reaches a maximum depth of 650 meters, serving as the core hub of the development.

This high-altitude green-energy "super power bank" is rapidly taking shape and is expected to play a vital role in strengthening clean-energy supply security and enhancing grid regulation capabilities in China.