Multi-objective optimization of PV-CSP system in different dispatch strategies, case of study: Midelt city

Abstract

Photovoltaic-concentrated solar power (PV-CSP) hybridization has been experienced to combine the competitive advantages of the low cost of PV systems and the high energy dispatchability of a CSP plant coupled with a thermal storage system. The objective of this paper is to implement an optimization study of the PV-CSP system under different dispatch strategies, in order to get an optimal PV-CSP configuration and strategy to cover a baseload generation taking into account the equivalent operating hours for the power block. Therefore, a model of PV-CSP plant was established and a multi-objective optimization using the genetic algorithm was adopted. The purpose of the first optimization is to minimize the levelized cost of electricity (LCOE) and to maximize the capacity factor simultaneously. For the second optimization, reducing the dumped energy is added as a criterion. The results obtained were presented in a Pareto frontier that shows a trade-off between the three objectives. An example of the multi-criteria decision method called the TOPSIS method was applied to choose a unique solution. The selection of the dispatch strategy is highly linked to the optimal PV-CSP configuration obtained by optimization results. In addition, the concept of equivalent operating hours is used to further the selection of the dispatch strategy. The dispatch strategy that maintains the power block operation at minimum rated power is more suitable and results in a high capacity factor, low LCOE, and low dumped energy. Furthermore, it minimizes the turbine starts and maximizes power block operating hours. The simulation model has been investigated in a case study of Midelt city in Morocco.