Techno-economic optimization of a hybrid system composed of pumped hydro storage, photovoltaic module, and diesel generator in a multi-objective framework

Hybridization of photovoltaic (PV) module (as a non-dispatchable resource), diesel generator (as a dispatchable source), and pumped hydro storage (PHS) (as an energy storage) can provide a promising hybrid energy system (HES). The main outlook of the present study is to develop an efficient multi-objective framework for optimal design of an off-grid PV/diesel/PHS HES in which a wide range of parameters related to PHS system is optimized. In the optimization framework, nine decision variables (number of PV modules, number of diesel generators, reservoir installation height, reservoir depth, reservoir diameter, pump's rated power, turbine's rated power, charge pipe diameter, and discharge pipe diameter) are optimized with respect to two objective functions: total net present cost (TNPC) and loss of power supply probability (LPSP). To determine how TNPC is affected by the change of the input variables, a sensitivity analysis is conducted by varying capital cost of PV, PHS, and diesel generator. To obtain a well-distributed and widely spread Pareto front, a multi-objective chaotic crow search algorithm (MO-CCSA) is introduced. Simulation results show that at LPSP = 0% and 5%, levelized cost of energy is around 0.59 and 0.55 $/kWh, respectively. Moreover, variation of the PV capital cost has a significant impact on the TNPC value.