Energy and exergy-based sizing optimization of a stand-alone hybrid renewable energy system

The combination of solar and hydrogen energy has been recently proposed as a sustainable approach in hybridrenewable energy systems. This study proposes an energy system which integrates solar photovoltaic and solar thermalenergy along with hydrogen energy storage to supply heating, cooling and domestic hot water demands of a standalone building in Tehran. A dynamic modeling is carried out by the TRNSYS software and particle swarm optimizationis utilized to size the system such that minimum loss of power supply probability, exergy destruction and dumpedelectrical power are achieved. The optimized configuration delivers 30.54 MWh of energy, leaving no loss in powersupply and no electricity dump. The exergy analysis reveals that 73% of the total exergy destruction is caused by thephotovoltaic array followed by the solar thermal collector, alkaline electrolyzer and proton exchange membrane fuelcell. The PV array’s size is also found to have a direct linear impact on the total exergy destruction, making it the leastefficient component and primary driver of exergy loss. Meanwhile, the electrolyzer power is found to be exponentiallyrelated to the amount of electricity dump.