Optimal sizing of photovoltaic/fuel cell-based energy system with autonomous oxygen production for hospitals in four climatic zones of Pakistan: An economic-energy-environmental feasibility analysis

The main aim of this paper is to analyze the standalone systems to meet the electrical power demand without experiencing a shortage/blackout situation in different climatic zones. The primary objective is the on-site continuous oxygen production. The energy system consists of solar photovoltaic (PV), battery storage (BS), proton exchange membrane (PEM) fuel cell, PEM electrolyzer, hydrogen storage and oxygen storage are investigated. After designing systems architecture and simulations modelling, economic, energy and environmental assessments are performed with sensitivity analysis. The novel optimum system has power generation of 15.64 GWh/yr, from which solar PV generates 80.9% and fuel cell generates 19.1%. Furthermore, the oxygen production is 923,855 kg/yr and hydrogen production is 115,574 kg/yr. It has 27.16 million USD of net present cost (NPC), 0.3159 $/kWh levelized cost of energy (LCOE). The optimum system has less than 0.01% of carbon mission in comparison to natural gas-fuelled combustion system.