A record-breaking hydropower turbine will power the Zala plant in Tibet, raising performance to 92.6% with 500 MW Pelton technology
Harbin Electric unveils the world’s most powerful Pelton turbine for the Zala hydropower station
China has claimed another global milestone in energy technology. Harbin Electric Corporation has officially unveiled a record-breaking 500 MW Pelton hydropower turbine, a massive component with a 6.23-meter diameter designed for the Zala pumped-storage plant in Tibet.
The turbine runner was developed by Harbin Electric Machinery Factory, a subsidiary of Harbin Electric Corporation, leveraging more than a decade of experience in impulse turbine systems. So far, the company has contributed to 67 units across 30 hydropower stations in China and abroad, including the renowned Three Gorges Dam.
Engineering a record-breaking hydropower turbine
This turbine sets records not only for its capacity but also for its structural complexity and scale.
The runner features 21 precision blades, has an outer diameter of 6.23 meters, a total height of 1.34 meters, and weighs approximately 80 tons. According to the company, the hub is the largest ever forged from martensitic stainless steel for a turbine application.
To handle mechanical stress at this scale, Harbin’s engineers used advanced numerical simulations to design an innovative structure combining forging and welding. Strategic segmentation was introduced to avoid high-stress areas around the blades.
During the welding phase, digital monitoring tools optimized the process parameters, improving joint toughness and fatigue resistance. The company also developed a full lifecycle quality control framework called “7 stages + 14 inspections,” which integrates digital simulation and advanced physical testing.
Four-year development, significant performance gains
“The entire research and development process spanned four years and included five major revisions,” the company stated. Over 100 design solutions were analyzed, leading to the creation of six prototype runners and six scaled test models.
The results were significant: “The turbine achieved a breakthrough in hydraulic performance, operational efficiency, and load capacity,” according to Harbin Electric.
The unit met size, stress, and hardness targets on the first attempt, achieved a non-destructive testing qualification rate of 98.04%, and improved its operational efficiency from 91% to 92.6%.
Zala station and China’s hydropower strategy
The record-breaking hydropower turbine will be installed at the Zala pumped-storage hydropower station, currently under construction on the Yuqu River in Tibet. With a total installed capacity of 1 GW, the plant will host two 500 MW Pelton turbines.
These turbines have been designated by China’s National Energy Administration as key technical equipment projects due to their high altitude, extreme head, and large capacity. They play a strategic role in China’s plan to expand hydropower infrastructure in the southwest.
Owned by China Datang Corporation and operated by Datang Yuquhe Hydropower Development, the plant is expected to generate nearly 4 million megawatt-hours of electricity per year. It is scheduled to begin operation in 2028.
China remains the world’s largest developer of hydropower. With more than 430 GW of installed capacity, the country continues to lead global growth. In 2024 alone, China accounted for 14.4 GW of the 24.6 GW of new hydropower installed worldwide.
