Chinnasami Sivaji et.al / Journal on Materials and its Characterization 3(4), December 2024, 42-51 Copyright@ REST Publisher 42 Journal on Materials and its Characterization Vol: 3(4), December 2024 REST Publisher; ISBN: 2583-6412 Website: http://restpublisher.com/journals/jmc/ DOI: https://doi.org/10.46632/jmc/3/4/6 Penstock Material Selection in Hydropower Plants Using EDAS Method * Chinnasami Sivaji, Manjula Selvam, Vidhya Prasanth, M. Ramachandran REST Labs, Kaveripattinam, Krishnagiri, Tamil Nadu, India. *Corresponding Author Email: chinnasami@restlabs.in Abstract. Due to the severe working circumstances and the lengthy service life anticipated from these structures, choosing suitable materials for penstocks in hydropower plants is a crucial task that demands careful attention. The assessment and choice of penstock materials in hydropower plants is the main focus of this study's use of the EDAS (Evaluation based on Distance from Average Solution) approach. The EDAS technique optimises the decision-making process by combining the benefits of objective as well as subjective criteria. Introduction: To ensure the effective and consistent operation of these structures, it is essential to use the right elements for penstocks in hydropower plants. Penstocks are crucial parts that transport highly pressurised water from the reservoir to the turbines, where the energy is captured to produce power. The selection of penstock materials is crucial in determining the durability and efficiency of the hydropower plant due to the rigorous operating circumstances, such as high pressures, turbulent flow, and probable exposure to corrosion. His research aims to develop the methods for choosing penstock materials, ensuring the efficient and dependable operation of hydropower plants in spite of difficult environmental circumstances and long lifespan expectations. Research significance: In order to improve durability, operational efficacy, affordability, environmental sustainability, and safety, penstock material research is essential for hydropower plants. The results of this type of study can help the industry make decisions that maximise the efficiency and durability of hydropower facilities. Method: Using the EDAS technique, decision-makers can objectively assess and rank alternatives while methodically taking into account a variety of criteria. It aids in the facilitation of informed decision-making in difficult situations by taking into consideration both the relevance of criteria and the distances from the typical solution. Alternate parameters: Poly vinyl chloride (PVC), High-density polyethylene (HDPE), Glass reinforced plastic (GRP), Mild steel (MS) Evaluation parameters: Yield strength (YS), Life (L), Thickness (T), Material cost(C), Maintenance cost (MC). GRP got 1st rank, MS got 2nd rank, PVC got 3rd rank and HDPE got 3rd rank. GRP got 1st rank with less compensation. Keywords: Penstock material selection, hydropower plants, EDAS method, decision-making, criteria, performance evaluation. 1. INTRODUCTION The plant's components are the powerhouse, fast tube (penstock), spillway, silent pond, dam or weir and carrier Channel, exhaust pipe, and actuator Room. The dam's initial components having the entire facility and water flow across it operate the river. Its purpose is to keep water in a certain location. It is the point where water entering the facility is handled. It is near the dam's Carrier Channel exit. As a conduit, carrier channel transports water to a power loom pressure is a fast pipeline or penstock pipeline supplying a still pond with water as a water turbine [1]. The majority of penstock problems occurred in buildings under 50 years old or new. Including a thorough penstock inspection programme is the primary goal of adopting a penstock safety programme. The task is to make sure that every penstock is used, maintained, and operated safely and effectively. Key advantages of regular penstock inspections have the greatest benefits [2]. There are analyses of different penstock products taking into account factors like corrosion, weight, cost, and friction. Use couplings and a pressure penstock, which can represent up to 40% of the project's overall cost, are frequently more expensive but necessary for the MHP system to function dependably. There are several factors to consider when determining which material to use for a particular penstock design. Factors include the pipe's inner surface roughness, connecting method, weight, simplicity of setup, site access, design life, maintenance requirements,