Two Super-Deep Shafts of Zhejiang Songyang Pumped Storage Power Station Fully Penetrated

On May 2, the No. 2 shaft of the Zhejiang Songyang Pumped Storage Power Station, a key implementation project of China’s 14th Five-Year Plan, was penetrated. Following the penetration of the No. 1 shaft at the end of 2025, the two shafts arranged at the power station have now been fully penetrated with the assistance of the intelligent operation equipment "Tiangong Hao". The excavation depth sets a new record in China’s pumped storage industry, marking a new breakthrough in the field of intelligent construction of ultra-deep shafts in China.

Both of the two ultra-deep shafts of the Songyang Pumped Storage Power Station have a depth of 637 meters, equivalent to vertically embedding two 200-storey high-rises into the mountain. The power station consists of an upper reservoir, a lower reservoir, a water conveyance system, an underground powerhouse and a ground switch station, with its water diversion system adopting a primary shaft layout.

Xinhua News Agency reports that the construction faced complex geological conditions such as ultra-depth, faults, water seepage and ultra-hard rock, which brought numerous difficulties to the traditional drilling and blasting method in terms of construction efficiency and operational safety. To address these challenges, China Three Gorges Corporation innovatively applied China’s independently developed first set of 700-meter-class ultra-deep shaft intelligent operation equipment, with the 480-ton "Tiangong Hao" full-face shaft boring machine as its core.

"Tiangong Hao" adopts a unique conical cutterhead design that can adapt to complex rock stratum conditions. Through the integrated layout of five layers of platforms, it integrates subsystems such as propulsion, support, water supply, electrical control, laser guidance, fire protection and 5G communication network, realizing intelligent shaft forming with "no one underground and remote control on the ground".

During construction, "Tiangong Hao" performed excellently. It set an industry record with a maximum monthly excavation progress of 278.28 meters for the No. 2 shaft, improving construction efficiency by 10 times compared with the traditional method and completing the excavation and support of a single shaft safely and efficiently in only 61 days. The 700-meter-class intelligent shaft hoisting system cooperating with "Tiangong Hao", like an "intelligent elevator" going deep underground, has a maximum lifting height of 700 meters, capable of safe transportation of personnel and hoisting of 60-ton heavy objects, solving the problem of safe and efficient transportation of personnel and materials in ultra-deep shaft construction.

China Energy News states that the project team has continuously optimized the construction technology system in practice. After completing the construction of the No. 1 shaft, the team made a number of improvements in the construction of the No. 2 shaft: accurately controlling blasting parameters to shorten the construction period of the initial section from one month to two days; optimizing the muck removal process to achieve efficient connection between excavation and muck removal; and simultaneously improving equipment waterproofing, underground lighting and safety protection measures, as well as applying new high-adhesion support materials to further enhance project quality and construction safety.

Located in Songyang County, Lishui City, Zhejiang Province, the Songyang Pumped Storage Power Station is a daily-regulating pure pumped storage power station. It is designed to install 4 reversible hydropower generator units with a single unit capacity of 350,000 kilowatts and is scheduled to put the first unit into grid-connected power generation by the end of 2027.

Once completed, the power station will mainly undertake tasks such as power grid peak shaving, valley filling, energy storage, frequency modulation and emergency backup. It will play an important role in ensuring the safe and stable operation of the East China Power Grid and promoting the consumption of new energy. Moving forward, the project team will continue to promote the construction process steadily, ensuring the power station is put into operation as scheduled to provide strong support for regional energy security and high-quality development.