Magnetically-accelerated large-capacity solar-thermal energy storage within high-temperature phase-change materials

Abstract

Solar-thermal energy storage within phase change materials (PCMs) can overcome solar radiation intermittency to enable continuous operation of many important heating-related processes. The energy harvesting performance of current storage systems, however, is limited by the low thermal conductivity of PCMs, and the thermal conductivity enhancement of high-temperature molten salt-based PCMs is challenging and often leads to reduced energy storage capacity. Here, we demonstrate that magnetically moving mesh-structured solar absorbers within a molten salt along the solar illumination path significantly accelerates solar-thermal energy storage rates while maintaining 100% storage capacity. Such a magnetically-accelerated movable charging strategy increases the latent heat solar-thermal energy harvesting rate by 107%, and also supports large-area charging and batch-to-batch solar-thermal storage. The movable charging system can be readily integrated with heat exchanging systems to serve as energy sources for water and space heating by using abundant clean solar-thermal energy.