Performance comparison of solid-state and fluid-driven thermal storage system

This paper aims to compare the performance and efficiency of fluid-driven (FD) and solid-state (SS) systems, which are used for solar heating using parabolic trough. Sodium nitrite (NaNO₂) was considered as phase change material (PCM) and both storages had the same storage capacity. To evaluate system performance, constant heating of 1 kW was provided to both systems to replicate solar energy. The fluid-driven system showed maximum efficiency of around 47% as compared to 20% of solid-state system. Although the operating temperature of FD is higher than SS, as temperature increases flow rate of fluid also increases in FD which results in reducing the melting time of PCM. FD shows potential for providing better efficiency and can help utilize solar energy during evening/night when no sun is present.