Liquid metal technology in solar power generation - Basics and applications

In solar power generation, not only does the heat transfer significantly affect the energy conversion efficiency, but it also determines the stability and durability of the optoelectronic materials. Therefore, special attention has been given to the development of advanced heat transfer materials and methods to achieve more efficient energy conversion. Recently, low-melting-point liquid metal materials have emerged as an attractive heat transfer medium, owing to their unique properties, such as, low melting point, high thermal conductivity, high latent heat, nonflammability, and non-toxic characteristics. Various heat transfer systems based on liquid metals have been investigated, and consequently, significant advances in liquid metal material properties, industrial thermal management, and solar power generation have been achieved. This paper presents a thorough review on basics and applications of liquid metal technology in solar power generation. Specifically, three typical liquid metal materials, including liquid metal fluids, liquid metal thermal interface materials, and liquid metal phase change materials are introduced. Some typical liquid metal based solar power applications, including the liquid metal cooling enhanced photovoltaic power generation, the liquid metal based solar thermal power generation, the liquid metal based solar thermal magnetohydrodynamic (MHD) power generation, the liquid metal thermal interface material enhanced heat transfer in solar energy system, and the liquid metal based solar thermal storage system are illustrated and interpreted. Both these fundamental issues and their latest application researches are elaborated and critical issues are discussed. Eventually, the paper concludes with a description of future developments and challenges in these areas.