Selection of Sol-Gel Coatings by the Analytic Hierarchy Process and Life Cycle Assessment for Concentrated Solar Power Plants

Sol-gel coatings are commonly used to prevent corrosion from molten salt mixtures in CSP plants. Until now, they have been driven primarily by cost considerations, without integrating environmental criteria into the modeling and decision-making process. The novelty of this study lies in the development of an evaluation framework that incorporates environmental impact alongside technical and economic factors, providing a more sustainable approach. This work assesses porosity, thermal shock resistance, and thickness to determine the optimal sol-gel coating. For this purpose, the multi-criteria decision-making technique “Analytic Hierarchy Process” (AHP) and the Life Cycle Assessment (LCA) methodology are implemented. The results show that the scores obtained for the 3YSZ-5A (5% mol) coating are higher than those of the 3YSZ (3% mol) and 3YSZ-20A (20% mol) coatings, between 1.52 and 1.69, respectively. The 3YSZ-5A coating (5% mol) is the optimal solution among all the systems analyzed, with a score of 0.61 AHP pt. The coating of the same type and higher molar concentration (20%) achieved 0.55 AHP pt. Finally, the 3YSZ type coating received the lowest rating, with a score of 0.36 AHP pt. The insights generated in this research will support decision-making in the design and maintenance of CSP plants.