Multi-objective optimal analysis on the distributed energy system with solar driven metal oxide redox cycle based fuel production

Solar energy driven cerium dioxide (CeO2) thermochemical cycle based fuel production is considered to be a promising technology that can integrate with a combined cooling, heating and power (CCHP) system owing to the pollution free property and favorable chemical reaction kinetics characteristics. In this study a combined cooling, heating, power and fuel (CCHPF) distributed energy system is devised to improve the energy utilization efficiency and reduce the dependence on conventional fossil fuels. To realize the efficient and cost-effectively operations of the system, a constrained multi-objective optimization problem with aims of maximizing primary energy saving ratio (PESR) and minimizing CO2 emission and energy cost is proposed to search for the optimal operation strategy and schedule. A potent optimization method that capitalizes on the advantages of the non-dominated sorting genetic algorithm-II (NSGA-II) and the random walk with directional exploitation (RWDE) algorithm is developed to solve the proposed optimization problem more effectively. The fuzzy decision making method is tailored to determine the final operation strategies of the CCHPF system from the obtained Pareto front according to the decision maker preferences. Numerical results show that the proposed system realizes the supply-demand balance, the optimal dispatch of the energy and the efficient economic operation. In comparison with existing CCHP systems, the energy utilization efficiency of the developed CCHPF system increases by 0.60% and 17.65%, CO2 emission decreases by 13.79% and 3.77%, as well as economic cost reduces 0.29% and 6.33% on a typical winter and summer days, respectively. The research findings provide new insights for improving the coordinated operation of distributed renewable energy system and alleviating energy crisis and environmental pollution. (C) 2019 Elsevier Ltd. All rights reserved.