Multi-objective optimization of a novel combined cooling, heating and power solar thermal energy storage system: A comprehensive analysis of energy, exergy, exergoeconomic, and exergoenvironmental performance

Efficient utilization of the renewable energy to meet the demands for cooling, heating, and power is an effective pathway for achieving carbon neutrality. In this paper, a novel combined cooling, heating, and power solar thermal energy storage system is proposed, consisting of a supercritical CO₂ cycle coupled with a Rankine-lithium bromide absorption cycle. System performance is evaluated from the perspectives of energy, exergy, exergoeconomic, and exergoenvironmental (4E) analysis. A multi-objective optimization method based on the multidimensional scaling dimensionality reduction algorithm for 4E analysis is introduced. The 4E analysis indicate the pressure ratio (PR) has the most significant impacts on system performance, with exergy efficiency reaching 55.30 % and thermal efficiency attaining 25.65 % as PR increases. Enhancing performance of the condenser and the evaporator is the optimal method for further improving system exergy efficiency. The solar power tower and heliostat field constitute the largest component cost portion, comprising 78.45 %. Meanwhile, the miniaturization and lightweight design of components are primary strategies for optimizing system environmental performance. Multi-objective optimization results show that, compared with single-objective optimized operating conditions, sacrificing a small portion of thermodynamic and exergy performance can reduce the unit cost of system product by 4.753 % and the unit environmental impact by 3.342 %.