Simulation of a Hybrid Concentrated Solar and Biomass-Fuelled Trigeneration System for Residential Applications

Solar technologies stand out as effective solutions for decarbonising the building sector. Among them, Concentrated Solar Power (CSP) systems offer the advantage of delivering flexible and dispatchable power. However, hybridisation with other renewable energy sources is often pursued to extend the operational hours. Therefore, this study investigates the complementarity of solar energy with biomass combustion within a small-scale hybrid trigenerative plant. More precisely, the proposed system consists of a 240 kWth peak thermal power Linear Fresnel Reflectors solar field combined with a 130 kWth back-up biomass boiler to supply heat to a 20 kWel/100 kWth Organic Rankine Cycle (ORC) unit for the provision of cooling, heating and electric power to 10 apartments. The hybrid plant also integrates thermal energy storage tanks and a battery energy system to increase the solar energy self-consumption and reduce the intervention of the grid. The performance of the hybrid system is analysed through an advanced simulator developed by the authors in MATLAB/Simulink considering the components’ inertia. The results reveal an increment in solar energy self-consumption achieved by exploiting the low solar irradiance to bring the latent heat thermal energy storage into its melting range, thereby extending ORC operation into nighttime hours. More precisely, the system meets the entire annual thermal demand for space heating, cooling and domestic hot water through renewable sources, consuming 2.25 tons of biomass. Electric demand coverage, instead, reaches up to 81% with the inclusion of a 60 kWhel battery energy storage system.