Name: Jixi Pumped Storage Power Station
Address: CN

Overview

The Jixi Pumped Storage Power Station is a significant pumped-storage hydroelectric facility located in Jixi County, within Anhui Province, China. As a key component of the regional energy infrastructure, the station utilizes water as its primary energy source, functioning through the mechanism of pumped-storage technology. This operational model allows for the efficient management of electricity demand by storing potential energy in water reservoirs, which is then converted back into electrical power during peak consumption periods. The station is currently classified as operational, having completed its initial construction phases and unit commissioning schedules.

The development of the Jixi facility began with preliminary studies conducted in 2008, laying the groundwork for the engineering and logistical requirements of the project. Construction officially commenced in December 2010, with an initial projected timeline of six years for completion. A major structural milestone was reached by April 2017, when the dam was reported as completed, marking a critical phase in the hydroelectric infrastructure's readiness for turbine integration.

The commissioning of the power generation units proceeded in a phased manner over several years. The first turbine was brought online in December 2019, initiating the station's contribution to the local grid. This was followed by the commissioning of the second unit in May 2020. The third and fourth units were subsequently commissioned in August 2020, significantly increasing the station's output capacity. The final two units were commissioned in February 2021, completing the installation of all six generating units. The total installed capacity of the Jixi Pumped Storage Power Station stands at 1800 MW, providing substantial flexible power generation capabilities for the Anhui Province grid and the broader Chinese energy sector.

History and Construction Timeline

The Jixi Pumped Storage Power Station project in Jixi County, Anhui Province, China, began with preliminary studies in 2008. The infrastructure development progressed through the completion of the dam, which was finalized as of April 2017.

Unit Commissioning

The operational phase started with the commissioning of the first turbine in December 2019. This was followed by the second unit in May 2020, and the third and fourth units were brought online in August 2020. The final two units were commissioned in February 2021, marking the full operational status of the 1800 MW facility.

Year	Event
2008	Preliminary studies conducted
December 2010	Construction began
April 2017	Dam completed
December 2019	First turbine commissioned
May 2020	Second unit commissioned
August 2020	Third and fourth units commissioned
February 2021	Last two units commissioned

How does the Jixi Pumped Storage System Work?

The Jixi Pumped Storage Power Station operates as a critical component of the regional energy grid, utilizing water as its primary energy storage medium. The facility is situated in Jixi County, Anhui Province, China, leveraging the natural topography to create a significant hydraulic head essential for efficient energy conversion. This hydraulic head represents the vertical distance between the upper and lower reservoirs, a key factor in determining the potential energy available to drive the turbines during peak demand periods.

Underground Power House Configuration

To optimize land use and structural stability, the power station features an underground powerhouse. This design choice is common in pumped-storage facilities located in mountainous or hilly terrains, allowing for the integration of large machinery while minimizing surface footprint. The underground location helps maintain consistent operating temperatures for the electrical equipment and provides natural shielding for the generators. Construction of this complex infrastructure began in December 2010, following extensive studies initiated in 2008. The dam, a critical component of the water retention system, was completed by April 2017, marking a significant milestone in the project's timeline.

Turbine-Generator Operation

The station is equipped with six Francis pump turbine-generators, each with a capacity of 300 MW, contributing to the total installed capacity of 1800 MW. Francis turbines are reversible units, functioning as both turbines and pumps. During periods of high electricity demand, water flows from the upper reservoir through the turbines, spinning the generators to produce electricity. Conversely, during periods of low demand, the units operate as pumps, drawing water from the lower reservoir back to the upper reservoir, effectively storing energy in the form of gravitational potential energy.

The commissioning of these units occurred in a phased approach. The first turbine was commissioned in December 2019, followed by the second in May 2020. The third and fourth units came online in August 2020, accelerating the station's output. This staggered commissioning allowed for systematic testing and integration of each unit into the grid, ensuring reliability and efficiency. The six-year construction period, as initially projected, culminated in a fully operational facility that enhances grid stability and renewable energy integration in Anhui Province.

What are the key technical challenges of high-head pumped storage?

The Jixi Pumped Storage Power Station operates with a rated hydraulic head of 599 m, a figure that places it among the high-head installations in China’s growing portfolio of pumped-storage assets. This head is derived from the significant elevation difference between the upper reservoir, situated at 961 m above sea level, and the lower reservoir, located at 339.3 m (Jixi Pumped Storage Power Station technical profile). Such a vertical separation is not merely a geographical feature but a primary driver of the plant’s energy density and mechanical design requirements. The 599 m head allows for a more compact turbine-generator assembly compared to low-head counterparts, as the potential energy per unit volume of water is substantially higher. This efficiency is critical for the station’s 1800 MW installed capacity, enabling rapid response times essential for grid frequency regulation and peak-shaving in the Anhui Province power network.

Structural and Hydraulic Implications

Managing a 599 m hydraulic head imposes rigorous demands on the civil and mechanical infrastructure. The penstocks conveying water from the upper reservoir at 961 m to the turbine hall must withstand extreme static and dynamic pressures. The lower reservoir at 339.3 m serves as the tailwater reference, but the pressure differential during start-up, shut-down, and load rejection creates complex transient flows. Engineers must account for water hammer effects, where sudden changes in flow velocity generate pressure waves that can exceed the static head, potentially stressing the penstock walls and turbine runners. The completion of the dam in April 2017 was a critical milestone in establishing the structural integrity required to maintain the upper reservoir’s elevation and volume consistency. The construction period, which began in December 2010 and was expected to last six years, involved detailed geotechnical studies initiated in 2008 to ensure the mountainous terrain of Jixi County could support the weight and hydraulic loads of the upper basin.

Turbine Selection and Operational Dynamics

The choice of turbine technology is directly influenced by the 599 m head. High-head pumped storage typically employs Francis or Pelton turbines, or specialized reversible pump-turbines optimized for this pressure range. The Jixi station’s commissioning sequence reflects the complexity of integrating these units. The final two units were brought online in February 2021, completing the 1800 MW capacity. Each unit must efficiently operate in both pumping and generating modes, handling the high specific speed associated with the elevation difference between 961 m and 339.3 m. The hydraulic efficiency at this head is crucial for minimizing energy losses during the round-trip cycle, where water is lifted to the upper reservoir during off-peak hours and released through the turbines during peak demand. The precise alignment of the turbine runners and the smoothness of the spiral casing are vital to reduce cavitation, a common challenge in high-head operations where vapor bubbles form and collapse, eroding metal surfaces over time.

Why it matters

The Jixi Pumped Storage Power Station serves as a critical infrastructure asset for the energy grid in Anhui Province, China. With a total installed capacity of 1800 MW, the facility plays a significant role in regional energy storage and load balancing. Pumped-storage hydroelectricity is widely recognized for its ability to provide rapid response times and large-scale energy storage, which are essential for stabilizing grids with increasing shares of variable renewable energy sources. In the context of Anhui Province, the Jixi station helps to manage peak demand and integrate fluctuating power inputs, thereby enhancing the overall reliability and efficiency of the regional power supply. The station's development timeline reflects a strategic approach to modernizing the local energy infrastructure. Studies for the project were initiated in 2008, followed by the commencement of construction in December 2010. The project was expected to last 6 years, although the commissioning of individual units extended the operational rollout. The dam was completed by April 2017, marking a major milestone in the construction phase. The first turbine was commissioned in December 2019, with the second unit following in May 2020. The third and fourth units were brought online in August 2020, and the final two units were commissioned in February 2021. This phased commissioning allowed for gradual integration into the grid and testing of operational parameters. The operational status of the Jixi station as of 2021 indicates that it is fully functional and contributing to the energy mix. The 1800 MW capacity provides substantial storage potential, allowing for the pumping of water to an upper reservoir during periods of low demand and releasing it through turbines during peak hours. This process helps to flatten the load curve and reduce the need for peaking power plants, which are often less efficient and more expensive to operate. The station's location in Jixi County, Anhui Province, positions it strategically to serve the growing energy needs of the region, supporting both industrial and residential consumption. The significance of the Jixi Pumped Storage Power Station extends beyond its immediate technical specifications. It represents a key investment in the flexibility of the Chinese energy grid, which is undergoing rapid transformation. As China continues to expand its renewable energy capacity, particularly wind and solar power, the need for effective storage solutions becomes increasingly important. The Jixi station provides a proven and reliable method for storing excess energy and releasing it when needed, thus reducing curtailment and improving the overall utilization of renewable resources. This contributes to the broader goals of energy security and sustainability in Anhui Province and the wider region.

Jixi Pumped Storage Power Station