- What happened: China put into full operation a pumped‑storage hydropower plant in Jurong City, Jiangsu, with the tallest dam of its kind worldwide. Xinhua News
- Who built it: A subsidiary of State Grid Corporation of China (State Grid Xinyuan) led the project. Xinhua News
- How big it is: 1.35 GW of installed capacity, designed to produce 1.35 billion kWh a year; six 225‑MW reversible units feed the grid. Xinhua News
- The record: The upper‑reservoir dam is 182.3 m high (≈60‑storey building) and the reservoir holds up to 17.07 million mł of water — the tallest pumped‑storage dam on Earth, confirmed by engineering literature. Xinhua News
- Why it matters for Jiangsu: The manufacturing hub has seen repeated record summer loads (152–156 GW), making flexible storage critical to keep the lights on. China Energy Storage Alliance
- Grid hook‑up: A 500‑kV transmission upgrade was completed to move the plant’s power where it’s needed most in the Yangtze River Delta. Asian Power
- Bigger picture: China is on track to exceed its 2030 pumped‑storage target, potentially reaching ~130 GW, as global pumped‑storage capacity climbed to ~189 GW in 2024. Reuters
China’s newest grid “shock absorber,” explained
China has switched on a 1.35‑gigawatt pumped‑storage hydropower station in Jurong, Jiangsu—a province that anchors the Yangtze River Delta’s heavy industry and surging power demand. Built by State Grid’s pumped‑storage arm (State Grid Xinyuan), the station shifts electricity from low‑demand periods to peak hours by pumping water uphill and later releasing it through turbines—behaving like a giant, rechargeable “water battery.” Xinhua News
At the heart of the project is a record‑setting 182.3‑meter asphalt‑concrete‑faced rockfill dam that impounds the station’s upper reservoir, a feat documented not only in news dispatches but also in technical proceedings on dam engineering. The reservoir can store up to 17.07 million cubic meters of water. Xinhua News
The plant’s six reversible 225‑MW units can rapidly switch between pumping (charging) and generating (discharging), delivering fast ramping and peak shaving for the regional grid. To integrate the project, State Grid completed a 500‑kV supporting transmission line last year, ensuring the new capacity can relieve stress in load centers across Jiangsu. WAM
Why Jiangsu needed it now
Jiangsu’s electric demand has shattered records amid searing summer heat and industrial growth. State Grid reports and market trackers logged new highs above 150 GW this summer, repeatedly eclipsing past peaks—pressure that storage can help absorb by shifting off‑peak energy into the crunch hours. China Energy Storage Alliance
“Once fully operational, the station ‘can help ease grid pressure during peak time and boost the consumption of power from wind and solar,’” said Wang Chenhui of the State Grid Zhenjiang Power Supply Company. China Daily
How pumped storage works—and why it’s different from batteries
Pumped‑storage hydropower (PSH) stores energy as elevation, using gravity instead of chemical reactions. Unlike typical grid batteries designed for minutes to a few hours, PSH commonly provides long‑duration storage and high power output (hundreds to thousands of megawatts), while supplying critical ancillary services such as inertia, frequency control, voltage support, and black‑start capability for grid restoration. Hydropower
The International Hydropower Association (IHA) calls pumped storage the world’s largest “battery” technology, and its latest World Hydropower Outlook 2025 notes that global PSH capacity rose to ~189 GW by the end of 2024 as countries race to firm variable wind and solar. As IHA CEO Eddie Rich put it, “pumped storage hydropower is playing an increasingly vital role in ensuring system flexibility and stability.” Hydropower
A record height, confirmed by engineers
Beyond headlines, civil‑engineering documentation underscores the project’s novelty: the Jurong upper‑reservoir dam is not only the tallest dam used for a pumped‑storage station (182.3 m), it also tackles complex karst geology with an asphalt concrete face and a composite anti‑seepage system (asphalt on the walls, geomembrane on the floor). These design choices are detailed in a chapter presented to the International Congress on Large Dams. Taylor & Francis API
Part of China’s storage surge
China is building long‑duration storage at an unprecedented clip. According to IHA and Reuters reporting, the country added 7.75 GW of PSH in 2024, reaching ~59 GW and is on track to exceed its 2030 target, potentially hitting ~130 GW. In parallel, China’s “new energy storage” (predominantly grid batteries) surpassed 100 GW cumulative by mid‑2025, reflecting a two‑track strategy: batteries for fast, short bursts; hydropower storage for longer, bulk shifts. Reuters
How it stacks up against other mega‑projects
The Jurong project sets a height record, but China also hosts the largest PSH plant by capacity: Fengning in Hebei at 3.6 GW, fully completed in 2024. Together they show two ways PSH can scale—taller dams to maximize head (Jurong) and more units to maximize power (Fengning). Hydropower
What it means for businesses and households
Because PSH can buy cheap off‑peak power and sell dear at peak, grid operators use it to flatten price spikes, cut curtailment of renewables, and improve reliability during heat waves and cold snaps—benefits that ultimately stabilize bills and keep factories humming. China’s grid company says it has commissioned 78 PSH units since 2021 (total ~44.5 GW) as part of a broader effort to harden the system against weather‑driven extremes. Xinhua News
Environmental and siting notes
Pumped storage has site‑specific trade‑offs. Studies by national labs and international agencies find that closed‑loop designs (off‑river reservoirs) often have lower environmental footprints than river‑connected schemes, and good practice focuses on water sourcing, seepage control, habitat protection, and careful construction management. In Jiangsu’s case, engineers documented extensive anti‑seepage and foundation treatments to manage karst risks. The Department of Energy’s Energy.gov
What to watch next
- Dispatch role this winter and next summer: How often the plant cycles will show how much peak‑load shaving and renewable absorption it delivers in Jiangsu’s tight power seasons. Xinhua News
- China’s storage buildout vs. needs: The IEA says the world needs ~1,500 GW of energy storage by 2030 in a net‑zero pathway; pumped storage is expected to carry a significant share of long‑duration needs alongside rapidly growing batteries. IEA
- More records to come: With a PSH pipeline measured in the hundreds of gigawatts, expect more Chinese projects to set records—by height, head, or power—as provinces replicate the Jurong model near load centers. Hydropower
Sources and expert commentary used in this report
- Xinhua and China Daily on the commissioning day, location, builder, 1.35‑GW capacity, 1.35‑billion‑kWh annual output, 182.3‑m dam and 17.07‑million‑mł reservoir; including a quote from Wang Chenhui (State Grid Zhenjiang). Xinhua News
- Engineering proceedings (Taylor & Francis / ICOLD) confirming the 182.3‑m dam as the world’s tallest for a pumped‑storage station and detailing anti‑seepage design in karst conditions. Taylor & Francis API
- WAM and project notes on six 225‑MW units and grid integration context; Asian Power on the 500‑kV supporting line. WAM
- IHA World Hydropower Outlook 2025 for global PSH capacity (~189 GW) and policy context; IHA CEO Eddie Rich on PSH’s rising role. Hydropower
- Reuters on China’s PSH trajectory—on track to exceed its 2030 target (~130 GW). Reuters
- CNESA on China’s >100 GW of “new energy storage” (batteries) by mid‑2025; IHA factsheet on PSH grid services. China Energy Storage Alliance
- Hydropower.org on Fengning as the largest by capacity (3.6 GW), framing Jurong’s global significance by height. Hydropower
