Materials development and its challenges for sustainability of hydropower plants: A review

This review focuses on the materials development utilized for enhancing long-term efficiency of hydropower plants and its sustainability. It begins by contextualizing the global transition toward renewable energy, distinguishing between renewable and non-renewable energy sources, and underscoring the strategic importance of hydropower in meeting growing ecological and energy demands. The study delves into the technological evolution of hydroelectric systems, with a focused analysis on the engineering design and materials employed in the underwater parts of hydro turbines susceptible to mechanical degradation. A comprehensive evaluation of materials is presented ranging from traditional options like wood and cast iron to modern solutions such as stainless steels, advanced steel alloys, polymer matrix composites, and nano-engineered materials, with a focus on their mechanical properties and resistance to cavitation, erosion, corrosion, and fatigue. The review also highlights surface modification and various processing such as heat treatment and thermomechanical processing techniques aimed at enhancing material performance under aggressive hydro-operating conditions. Finally, the paper identifies the key challenges in material selection and development for hydropower applications and outlines future directions needed to ensure improved durability, reduced maintenance, and overall enhancements in the efficiency of hydro turbine and sustainability of hydropower plants.