Corrosion mechanisms in molten salt thermal energy storage for concentrating solar power

Abstract

High temperature corrosion of molten salt containment materials is of great interest for thermal energy storage systems used with concentrating solar power. Mitigating this corrosion is critical for the design, life cycle and economics of these systems and requires understanding the mechanisms which drive corrosion. In molten salts these mechanisms are complex, and heavily influenced by factors such as impurities, atmosphere, temperature and metal composition. This review aims to illustrate the mechanisms of molten salt corrosion in thermal energy storage systems and the primary factors which affect them. As these factors are so important for corrosion mechanisms, much of the published corrosion rate data will be not be applicable to many thermal energy storage systems. This means that controlling these conditions and corrosion testing will be an indispensable part of developing cost-effective thermal energy storage systems.