Multi-criteria optimal design of hybrid clean energy system with battery storage considering off- and on-grid application

Abstract

This paper examines the optimal design of a hybrid photovoltaic-wind generator system with battery storage (PV-wind-battery) with off-grid and on-grid operation modes. The objective of the study is to supply annual load demand considering environmental emissions and energy generation cost, as well as the cost of load losses. The decision variables include the optimal size of photovoltaic and wind resources, transfer of the power of the inverter to the load, battery storage bank size, and photovoltaic panel angle. The angle is determined optimally using a meta-heuristic algorithm, i.e., the spotted hyena optimisation (SHO), considering minimisation of the objective function and satisfying the constraints. The objective function is defined as the sum of net present cost (NPC) of the system components and load losses and also cost of emissions (TNPC). The constraints are a maximum and minimum size of the system components and also reliability constraint as load interruption probability (LIP). In this study, first, an off-grid PV-wind-battery system was designed without considering emissions; then, an on-grid PV-wind-battery system was designed considering emissions. It was then optimized using SHO. The simulation results indicated that the PV-wind-battery and wind-battery combinations are the best and worst system combinations, respectively, in terms of TNPC and reliability indices. Additionally, the performance of the SHO algorithm was compared with that of the particle swarm optimisation (PSO), and the results proved the superiority of SHO in system design with a lower cost and better reliability indices. Moreover, the results cleared that the TNPC and LIP achieved 1.286 M$ and 0.13%, respectively, which were lower in the on-grid mode of the hybrid PV-wind-battery system designing compared to the results of the off-grid mode with 1.295 M$ and 0.19%. The obtained results showed that reliability can be improved by purchasing power from the network and considering minimisation of emissions in the on-grid operation mode. The impact of increasing the maximum available power of the network (MAPnet) was examined on the hybrid PV-wind-battery system designing. The results confirmed that the system reliability was improved and TNPC decreased by increasing the MAPnet, and vice versa.