Background. The use of hybrid renewable energy systems (HRES) based on diesel power plants supplemented with generating plants based on renewable energy sources is an effective way to improve the efficiency and reliability of electricity supply to decentralized consumers. Designing of HRES associated with the need to solve an optimization problem, when it is necessary to determine the optimal equipment configuration and their installed capacities in the context of multi-criteria.
Materials and methods. In the study, for multi-criteria optimization of HRES sizing a two-level approach is used. The top-level involves the formation of a set of Pareto-optimal alternatives – configurations of the HRES. At the bottom-level, an hourly simulation of the HRES operation is performed to assess each configuration according to the criteria. The most preferred configuration of the obtained set of Pareto-optimal alternatives is determined by the multi-criteria choice method. The methodological foundation of the two-level approach is ambiguous due to the variety of algorithms and methods. Previous research has demonstrated the efficiency of the NSGA-II algorithm for the top-level.
Results. The present study compares simulation modeling and linear optimization for simulating the operation of HRES at the bottom-level. A comparison of approaches to estimate criterion weights for the TOPSIS multi-criteria method, used to select the best alternative from the Pareto-optimal set, is also conducted. This study substantiates the expediency of using simulation modeling at the lower level of a two-level approach, based on a comparative analysis with the linear programming method. The Entropy method, the CRITIC method, and direct weight assignment by a decision-maker have been analyzed. The analysis of the multi-criteria evaluation results has been performed using both objective and subjective methods to assign criterion weights. A study of the solutions obtained on the basis of the proposed approach has been carried out using the example of the “Novikovo” of the Sakhalin region. The sensitivity analysis of multi-criteria estimates using the TOPSIS method has confirmed the sustainability of the solution to small changes in the preferences of a decision maker.
Conclusions. For multi-criteria optimization and decision making of the HRES sizing, the choice of methods for both generating the Pareto set using a two-level approach and for the final alternative selection from this set is of great importance. A comparative analysis of methods for the bottom-level showed that for a HRES with batteries, photovoltaic panels, wind turbines, and diesel generators, the use of simulation modeling is preferable to linear programming. Objective methods, such as CRITIC and entropy method, can be used for weighting; however, they cannot fully replace subjective weighting methods that reflect the preferences of the decision-maker.