Phase change material (PCM) candidates for latent heat thermal energy storage (LHTES) in concentrated solar power (CSP) based thermal applications - A review

Solar energy offers over 2,945,926 TWh/year of global Concentrating Solar Power (CSP) potential, that can be used to substitute fossil fuels in power generation and mitigate 2.1 GtCO2 of greenhouse gas (GHG) emission to support Sustainable Development Goals (SDGs) set by the United Nations (UN). Thermal energy storage (TES) is required in CSP plants to improve dispatchability, reliability, efficiency, and economy. Of all TES options, the latent heat thermal energy storage (LHTES) together with phase change materials (PCMs) exhibit the highest potential in terms of efficiency and economy. PCM properties thus become the ultimate decider of CSP performance. This paper reviews over 200 of published articles and websites to describe the history, identify the technologies, economics, and current trends of PCM as LHTES material for CSP plants. A list of 163 PCM candidates suitable for LHTES systems in low-temperature (T < 220 °C), medium-temperature (220 °C < T < 420 °C), and high-temperature (T > 420 °C) applications is presented for the first time. Research gaps are identified to determine the future directions.