Plantwide dynamic simulation of hybrid solar thermal power plant with molten salt thermal energy storage

A Solar thermal power plant (STPP) harnesses solar energy through mirrors or lenses to generate steam, which drives turbines for electricity production. Integration of thermal energy storage (TES) systems with STPP operations, enhances the reliability and flexibility of STPPs. The current study considers a hybrid STPP (HSTPP) where both parabolic trough collector and linear fresnel reflector act as solar concentrators. The HSTPP is integrated with molten salt two-tank indirect energy storage enabling uninterrupted electricity generation. Two detailed plantwide dynamic simulation studies of the HSTPP equipped with molten salt storage have been presented. Simulations over a two-day period demonstrate that with use of salt storage, the HSTPP is capable of continuously generating power, including at nighttime and during cloud cover periods in the daytime. Another case study highlighting plant performance in presence of seasonal variation over a typical year at two locations in India, namely Jaisalmer and Hisar, is also presented. The study highlights the role of TES in enabling nighttime power generation and shows that Jaisalmer outperformed Hisar in both steam output and electricity generation, achieving approximately 31% higher nighttime electricity production and 27% higher total annual electricity generation. The presented dynamic, plantwide HSTPP-TES model enables detailed insights into the plant behavior.