Hydropower is a sector where the development of novel technologies is underway to improve its sustainability and flexibility, and novel materials can play a central role in improving efficiency, resistance, reliability, extending lifespan, and making the fabrication, installation, and transport process easier. For example, it is worth noting that: ① Novel materials for turbines include superhydrophobic coatings and superhydrophobic lubricant-infused composites, coatings with triboelectric properties, bimodal coatings with both nanometric and micrometric WC grains, coatings 13Cr4Ni steel, Ni–Al
2O
3, and HVOF-sprayed WC coatings (e.g., Ref. [
105]); however, fiber-reinforced polymers including Kevlar
TM 49, HDPE, and carbon steel are limited to low-speed applications. ② Novel materials for dams and hydraulic structures include GFreinforced concrete, rock-bolted underpinning system, rock-filled concrete-cemented, and bituminous conglomerate. Significant development of geo-membrane placement on the upstream faces of concrete dams to reduce leakage and mitigate concrete expansion has been made [
106]. Novel materials for waterways include high tensile strength steel pipes and superhydrophilic surfaces to reduce friction losses. ③ The development of novel PCD, thermoplastic polymers (e.g., PTFE), and soft carbon graphite for bearings, and vegetable or water-based oils instead of common oil lubricants are underway, although more expensive [
107]. ④ In the ocean context, epoxies, and composite materials, and EPDM rubber for lining the reservoir of pumped hydropower plants are under consideration.