Energy assessment for integration of concrete thermal energy storage with low-grade solar power generation system

The energy storage systems are one of the essential components of the renewable energy systems to manage the energy supply and demand. The integration of a noval concrete thermal energy storage system with solar-driven organic Rankine cycle is studied in this paper. The Compound Parabolic Collectors (CPC) are used for absorption of solar energy. The solar energy is then transferred to Thermal Energy Storage (TES) and Organic Rankine Cycle (ORC) for heat storage and power generation. For evaluating the performance of porposed system, it is modeled numerically, and a parametric study is performed to find the optimum parameters of TES for maximizing the ORC working hour period. The results show that the increase in TES pipe length leads to an increase in TES charging time and heat capacity up to 82 h and 660 kW with 1000 m2 solar panel surface. Furthermore, the ORC working hours is extended by 3:10 h in a day by using the optimized TES concrete section with the length of 2000 m and diameter of 0.4 m. Additionally, the employment of TES in solar-driven ORC system resulted in the reduction of system power generation by 1.3% and an increment of heat generation by 0.49%.