The folds of Tianmu Mountain, Kuo Cang Mountain and Yandang Mountain hide the most precise adjustment codes of East China Power Grid. As of December 31, 2025, the total installed capacity of pumped storage power stations in Zhejiang Province reached 10.305 million kilowatts, making it the first province in the State Grid operating area to exceed 10 million. During the “14th Five-Year Plan” period, Zhejiang successively put into operation a large number of pumping and storage power stations such as Jinyun and Ninghai, and the installed capacity doubled compared with the “13th Five-Year Plan. What is more noteworthy is that the total installed capacity of pumped storage under construction and planning in the province is nearly 20 million kilowatts, which will rank first in the country in the future.
But the wild ride is much more than the numbers themselves.
The explosive growth of new energy installations in Zhejiang is a direct driver of pumping construction. By the end of 2025, Zhejiang clean power installed capacity for the first time exceeded the 0.1 billion-kilowatt mark, reaching 100.54 million kilowatts, accounting for 56.8 percent of the province’s installed power. Among them, the total installed capacity of scenery is 71 million kilowatts, an increase of 316.9 percent over the end of 2020, and photovoltaic has surpassed coal power to become the largest installed power source in Zhejiang. However, wind power PV relies on natural conditions, and its output is volatile and intermittent. It requires a variety of regulating resources such as pumped storage to undertake tasks such as peak regulation and frequency modulation to ensure the safe operation of the power grid. It is under this logic that Zhejiang uses the special terrain of “seven mountains, one water and two fields” to accelerate the construction of a pumped storage base in East China.
The technical breakthrough is equally eye-catching. In 2025, the first unit of Tiantai Pumped Storage Power Station will be connected to the grid, with the highest rated head of 724 meters in the world, the largest single-unit capacity of 425000 kilowatts in China, and the length of single-stage inclined shaft of 483.4 meters, setting a new domestic record. The commissioning of this power station marks the shift of China’s pumping technology from “parallel running” to “leading”-no longer catching up with international parameters, but defining the industry ceiling. The previous Changlongshan Power Station was fully put into operation in 2022, and all three indicators ranked first in the world, proving that domestic equipment can control the technical combination of “high head + high speed + large capacity. Ninghai Power Station demonstrated another dimension of breakthrough-Ninghai Power Station, which was fully put into operation in May 2025, adopted the world’s first large-diameter deep shaft hard rock roadheader, vegetation concrete ecological restoration and other innovative technologies, becoming the first power station in the national hydropower industry to be rated as “three-star” for green construction of electric power construction projects.
However, according to the relevant documents of the National Energy Administration, Zhejiang has suspended the approval of new projects because the scale of construction under construction (28.375 million kilowatts) is close to the 2035 demand forecast (30 million kilowatts). The 2022 special analysis predicts that the demand will be 30 million kilowatt-hours in 2035. The province’s capacity for operation and construction will be 22.98 million kilowatts, with 7 million kilowatts of construction space reserved. Only three years later, the actual scale has approached the target, and the deviation between planning and reality reflects the faster-than-expected development speed of new energy.
The deeper contradiction lies in the reassessment of the economy of pumping. With the continuous decline of electrochemical energy storage cost and the steady progress of thermal power flexibility transformation, the traditional advantage of pumping storage is facing the challenge of multiple technical routes. Zhejiang’s suspension of approval is not to deny the value of pumping, but to shift from “scale expansion” to “precise layout”-the remaining 1.625 million kilowatt gap will be used to fill the weak links of specific power grids, rather than continuing the blooming construction model.
Entering the “Fifteenth Five-Year Plan”, Zhejiang’s energy layout is clearer. According to the outline of the 15th five-year Plan for National Economic and Social Development of Zhejiang Province, from 2026 to 2030, Zhejiang will steadily promote pumped storage power station projects such as Songyang, Qingtian, Jiande, Jiangshan, Yongjia, Pan’an and Taishun, and promote the construction of lithium battery energy storage in an orderly manner, and explore the application of solid-state batteries and hydrogen energy storage. By 2030, pumped storage and new energy storage installed capacity will reach more than 30 million kilowatts. At the same time, wind power installed capacity and strive to reach more than 30 million kilowatts, photovoltaic installed capacity and strive to reach more than 90 million kilowatts, further optimize the energy structure. In the decomposition of key work responsibilities during the “Tenth Five-Year Plan” period issued by the Zhejiang Provincial Government, the promotion of pumped storage and the orderly development of new energy storage were included in the core agenda, and the new non-fossil energy installed capacity accounted for more than 75%.
looking back on the development track of Zhejiang’s pumping storage in the past 27 years-from the initial test cry of the 80 MW total installed capacity of xikou power station in 1998 to the large-scale application of 10.3 million kilowatts today, from the technology chaser to the standard setter, from “whether there is” filling in the blank to “whether it is good or not” intensive cultivation-this game on energy regulation is far from over. Pumped storage is not only the “standard” of new energy development, but also the “preferred” in specific scenarios “. In the next five years, whether Zhejiang pumping storage will realize the successful transformation from scale expansion to quality competition depends on a key judgment: when “enough” has become a fact, how to define “ahead of time”? This may be the most thoughtful proposition left to the industry by Zhejiang pumping storage.
