Solar energy, an abundant and cost-free power source, requires effective harnessing for sustainable energy solutions. Concentrated solar power (CSP) is a promising energy capture technology that uses optical devices to concentrate the power of the sun on to a surface and in turn generates power by means of a thermal-to-electric conversion unit. Current CSP technology is unfavourable as a renewable source of energy due to its high levelized cost of energy (LCOE). The 2030 target for CSP cycles are to be more than 50% efficient to reduce the LCOE to 5¢/kWh.

This research addresses the imperative need for improved CSP systems by focusing on the drawbacks associated with the prevalent use of molten salts as the Thermal Energy Storage (TES) material. The drawbacks of its use include high LCOE attributed to expensive capital costs associated to its use and limited working temperatures below 600 °C.

In response to these challenges, our approach involves the adoption of low-cost solid particle TES materials. A novel Recirculating Combined Fluidised Bed Particle Receiver (RCFBPR) system concept, designed to act as both the CSP receiver and heat exchanger, is introduced. This system is meticulously modelled using Ansys Fluent Computational Fluid Dynamics (CFD) simulation to analyse heat transfer and hydrodynamic performance, aiming for process intensification and LCOE reduction.

The research results unveil an optimised design, showcasing a receiver wall-to-solid particle heat transfer coefficient of 2.7 kW/m² K. This design translates to a commendable heat transfer rate of approximately 334 kW to alumina particles as the optimum TES material. Critical factors contributing to this include minimised convective heat loss, heightened particle contact surface area, continuous particle circulation, and the superior thermal conductivity of alumina compared to molten salts.

Furthermore, a comprehensive system cost analysis, utilising the System Advisor Module (SAM), estimates the LCOE of the proposed CSP system at 3¢/kWh. This competitive cost projection positions the CSP system favourably against other renewable energy sources, including wind and solar PV.