Geographic Influence on the Life Cycle Assessment of a 12W Polycrystalline Solar Photovoltaic Module in Southwest Nigeria

Abstract

This study examined the geographic impact on the life cycle environmental performance of a 12W polycrystalline solar photovoltaic (PV) module installed in six designated locations throughout Southwest Nigeria: Ogbomosho (Oyo State), Ikeja (Lagos State), Abeokuta (Ogun State), Osogbo (Osun State), Akure (Ondo State), and Iworoko (Ekiti State). As the demand for renewable energy technologies escalates, comprehending the geographical influences on the sustainability of solar PV systems is essential for maximizing its implementation. Nevertheless, there is a paucity of localized data regarding the environmental performance of small-scale photovoltaic modules across Nigeria's varied climatic zones. This study filled the gap by assessing life cycle indicators including cumulative energy demand (CED), energy payback time (EPBT), global warming potential (GWP), greenhouse gas payback time (GHG-PBT), greenhouse gas emission rate (GHG-ER), CO₂ emission rate, and CO₂ payback time. The method considered a system boundary encompassing the pre-manufacturing and manufacture stages in China, transit logistics from China to Nigeria, as well as the installation, operation, and end-of-life phases at six locations in Nigeria. The data indicated that CED values are uniform across sites, varying from 1231.86 MJ in Ikeja to 1232.10 MJ in Iworoko, with manufacturing accounting for around 97% of overall energy demand. EPBT values exhibit considerable variation owing to disparities in solar irradiation, with Ikeja documenting the highest value at 17.62 years and Iworoko the lowest at 15.95 years. GWP values varied from 66.31 kgCO₂eq in Akure and Osogbo to 136 kgCO₂eq in Ogbomosho, mostly affected by transportation distances and factory emissions. Correspondingly, GHG-PBT fluctuated from 5.66 years in Iworoko to 11.72 years in Ogbomosho, whilst GHG-ER ranged from 0.1031 to 0.2137 kgCO₂eq/kWh. The results underscore the environmental benefits of installing solar modules in high-irradiance regions and stress the significance of sustainable manufacturing processes and localized photovoltaic production to mitigate carbon footprints.