(TibetanReview.net, Mar01’26) – China is one step closer to running the world’s largest pumped hydro energy storage facility as its 4.2-GW hybrid project at Lianghekou – which combines conventional hydropower and pumped storage – nears completion, reported scmp.com Feb 28. The project is located in Nyagqu Dzong (Chinese: Yajiang County) of Kardze (Ganzi) prefecture in the formerly eastern Tibetan province of Kham (or Dotoe) but now part of the PRC’s enlarged Sichuan province.
The Lianghekou Dam (meaning “mouth of two rivers”), which is part of the project, entailed the relocation of over 4,900 residents during its construction, according to a Wikipedia report on the dam. It said the 295-metre-tall (968 ft) dam is the highest embankment dam in the PRC and supports a 3,000 MW power station.
The storage project being built at the Lianghekou Dam will have four units of 300 megawatts (MW) each when completed, making it the largest facility of its kind, said the scmp.com report.
The project is stated to house a conventional hydropower plant in addition to a pumped hydro energy storage facility. Pumped hydro works by moving water uphill when excess energy is being generated. When that energy is later needed, the water is released to flow downhill, spinning a turbine to create electricity in the process, the report noted.
The hydropower plant and the pumped hydro facility will together have a capacity of 4.2 gigawatts (GW), amounting to “the world’s largest hybrid pumped hydro storage system,” a recent report from Interesting Engineering was cited as saying. “The pumped hydro facility is designed to absorb green energy from the 7 GW of renewable energy plants being built on the plateau, making it the ‘super power bank’ of the region,” the article was stated to have noted.
Pumped hydro is a relatively simple technology with a long history in China. It’s a proven technology with long-term storage potential, making it indispensable in China’s increasingly electrified economy.
However, the technology also has its downsides, the report noted. Environmentalists often take a negative view of hydro megaprojects, as dams are extremely disruptive to ecosystems. And hydro systems are vulnerable to climate change, as drought can severely impact their output – as seen in Sichuan in 2022. But the Chinese government clearly feels that the benefits outweigh the risks, the report added.
Besides, being at the forefront of energy storage development and deployment is a key part of China’s bid to become the world’s first electrostate, the report said.
On a global level, the energy storage sector is seeing a meteoric rise, driven in large part by demand from utilities and data centers and the rapid growth of variable energies including wind and solar, and is gearing up to be “clean energy’s next trillion-dollar business.”
While the current energy storage landscape is dominated by lithium-ion batteries, this technology has some major drawbacks, including geopolitically fraught value chains (also dominated by China) and short energy storage duration, the report pointed out. lithium-ion batteries can hold onto energy for a matter of hours only. However, balancing energy flows from wind and solar will require storage systems that can hold onto excess energy for full days and even full seasons.
Long-term energy storage, such as pumped hydro, will therefore be increasingly indispensable in the coming years as the global clean energy transition continues to pick up steam, the report said.