A clearer look at energy storage with murky water

Pumped hydroelectric power stations are a promising low-cost alternative to battery electric storage to augment an electric grid increasingly supplied by renewable sources. Water is pumped from a source uphill into a reservoir using excess electricity, and is run downhill through a turbine when more electricity is needed.

When the water source is a sediment-laden river, erosion damage on major flow-passing components, such as runner blades and guide vanes, leads to high maintenance costs and component failure. Pang et al. simulated the flow of sediment particles within a pump-turbine to determine how vulnerable components wear over time.

“The systematic study of sediment wear and solid-liquid two-phase flow characteristics can not only fill the gap in the design and operation experience of hydromechanical pumped storage, but also have important engineering and strategic significance for improving service reliability and ensuring the safe and stable operation of the power grid,” said author Jiayang Pang.

The authors focused their attention on the hump region of the pump-turbine, a period during startup exhibiting low flow conditions. They used an Euler-Lagrange model to investigate this region, determining that these conditions lead to flow separation, backflow, and pressure pulsation inside the runner.

These simulations revealed the uneven wear caused by sediment. The authors believe that reinforcing those areas they found to be most affected and improving the design of turbine components can increase turbine lifespan and lower maintenance costs.

“By optimizing the structure of the runner and guide vane, the deflection effect of the stall unit and secondary vortex on the particle trajectory is weakened, and the energy dissipation and wear concentration in the local high shear area are reduced,” said Pang.

Source: “Study on the motion characteristics of sediment particles in the hump region of pump-turbine in a pump model,” by Jiayang Pang, Dandan Yan, Jialing Li, Xue Zhao, Feng Shang, Xiaobing Liu, and Lingjiu Zhou, International Journal of Fluid Engineering (2025). The article can be accessed at https://doi.org/10.1063/5.0278499 .

This paper is part of the 5th IAHR Asian Working Group Symposium on Hydraulic Machinery and Systems Collection, learn more here .