China expands pumped hydro storage

China has been aggressively expanding its pumped hydro storage capacity in recent years, positioning these power plants as crucial "stabilizers" for its evolving electricity grid as the nation embraces a greater share of intermittent renewable energy sources, a recent industry report reveals.

China's cumulative installed pumped hydro capacity exceeded 58 gigawatts (GW) by the end of 2024, with 7.75 GW of new capacity added in the past year alone, according to the China Renewable Energy Development Report 2024 released recently by the China Renewable Energy Engineering Institute.

Furthermore, 23 new pumped hydro storage projects were approved in 2024, further solidifying China's position as the world leader in pumped hydro storage for the ninth consecutive year, it said.

Pumped hydro storage power plants function like "giant batteries", utilizing surplus electricity during off-peak hours to pump water from a lower reservoir to an upper reservoir. During peak demand periods, this stored water is released to generate electricity.

While the global shift toward renewable energy is undeniable, the large-scale and high-penetration integration of wind and solar power into electricity systems presents challenges due to their inherent variability and intermittency, necessitating enhanced grid flexibility and regulation capabilities.

Under the circumstances, boosting pumped hydro storage capacity is essential for facilitating China's shift to green energy, responding effectively to critical situations, and ensuring overall energy security, said industry experts.

Zhang Zongliang, an academician with the Chinese Academy of Engineering, emphasizes the critical role of pumped hydro storage in addressing these challenges.

He believes significant market growth for pumped hydro storage in China is expected, driven by the increasing integration of wind and solar power into the energy system.

Pumped hydro storage serves as essential energy storage support for integrated clean energy bases, playing a pivotal role in the continued growth of renewables, he said.

Since the commissioning of China's first pumped hydro station in 1968, almost 90 years after the world's first facility was established in Zurich, Switzerland, the nation's expertise in this technology has matured through decades of practical application and technological accumulation.

Driven by national planning, supportive policies, and a robust industrial chain, China's pumped hydro storage sector has witnessed rapid growth in recent years.

By the end of 2024, the capacity under construction reached around 200 million kW, signaling significant future expansion. China has also come up with a comprehensive industrial system and specialized development model, covering standard formulation, planning and design, engineering construction and equipment, said Zhang.

According to the report by CREEI, pumped hydro storage projects in China are gradually expanding from the eastern coastal regions toward the west, often in larger scale.

With significant technological breakthroughs achieved in pumped hydro site investigation, construction, and equipment manufacturing, the country is well-positioned to help accelerate the global energy transition through its expertise in pumped storage, it said.

"China's pumped hydro technology has reached world-class levels," said Zhu Guojin, chair of the board of Beijing Engineering Corp.

Countries including Indonesia, Kazakhstan and the Philippines are showing strong interest in working with China to advance their own pumped storage capabilities, he said.

"The combined operation of pumped hydro with new energy sources like wind and solar can effectively reduce curtailment rates on the generation side and maintain stable grid operation," he said.