Thermodynamic investigations of the supercritical CO2 system with solar energy and biomass

In this work, a supercritical CO2 system integrating solar energy and biomass is proposed to mitigate the emission of the greenhouse gases, and realize the stable and efficient operation of the system. The proposed system mainly contains three parts, i.e., solar island, biomass burner and power block. With the consideration of the variations of the solar irradiation and the complementation of the biomass, the on-design and off-design thermodynamic performances of this system are numerically studied. Results indicate that the solar-to-electric efficiency of the system can reach to 27.85% at the design point, and the ratios of solar heat supply in the power cycle in four representative days are in the range of 15.7-36.4%. The exergy analyses are implemented to investigate the irreversible losses and the variation of the exergy destruction in the energy conversion process. The economic evaluations are carried out to illustrate the feasibility of the proposed system, and the LCOE of the system is 0.085 $/kW h. Theoretical results indicate that the supercritical CO2 system with multi-energies input is a promising option for the efficient utilization of the abundant solar and biomass resources in western China.