Life cycle assessment of integrated photovoltaic and hydrogen production systems for sustainable energy generation

Clean electricity production has become a major focus in recent years due to the rise in greenhouse gas (GHG) emissions annually. In this context, a site in Karachi, Pakistan, is considered for implementing a Renewable Energy System (RES) that integrates a photovoltaic (PV) system with hydrogen storage. This paper analyzes the environmental impacts linked with such system. A partial life-cycle assessment was performed within the defined system boundary to evaluate the environmental improvements and reduction in emissions for such a system. The ReCiPe2016 method is used for characterization factors, i.e., global-warming potential (GWP), ozone-formation potential (OFP), acidification potential (AP), and surplus ore potential (SOP). The results show that the total life-cycle GWP of the proposed system is 185.63 tons CO₂-eq, corresponding to a carbon emission rate of 0.36 kg CO₂-eq/kWh of electricity generated over the system lifetime. PV modules contribute to most of the GWP, OFP, and AP, while PEM electrolyzer and PEM fuel cell have an adequate share in SOP. Manufacturing contributes approximately twenty-four times the GWP associated with transportation. The energy payback time (EPT) is calculated to be 9.77 years, while the environmental payback time is calculated to be 9.87 years.