Life cycle assessment of photovoltaic panels including transportation and two end-of-life scenarios: Shaping a sustainable future for renewable energy

Abstract

This research study addresses the growing environmental concerns associated with solar photovoltaic (PV) systems which is a pivotal component of renewable energy transition. The primary objective is to advance the comprehension of the environmental sustainability of solar PV technology, with a specific focus on the context of Mexico. This study applies a life cycle assessment (LCA) framework, employing an up-to-date methodology (ReCiPe 2016) and database (Ecoinvent 3.8) for midpoint and endpoint indicators in this problem by considering a specific focus on end-of-life and transportation scenarios which have been absent in the current state-of-the-art research. An LCA approach bridges the gap between midpoint and end-point indicators, bringing transparency to the environmental impact assessment. This research entails a cradle-to-grave LCA of a 1 kW crystalline silicon solar panel over a 25-year lifespan while adapting to ISO 14044 standards for LCA and encompassing both midpoint and end-point indicators, specifically including end-of-life and transportation scenario. Furthermore, a sensitivity analysis is conducted to evaluate the variations in environmental indicators considering the life-cycle data. It is reported that recycling processes can cause a substantial mitigating effect on environmental impacts across multiple categories, leading to reductions of up to 89 % in mineral resource scarcity. Notably, the cell processing phase emerges as the most environmentally impactful stage, accounting for 37 % of the total impact. This high impact is predominantly attributed to silver usage and heightened electricity consumption. The sensitivity analysis revealed that various performance indicators exhibited differing degrees of sensitivity to uncertainty in the design variables, highlighting the importance of careful consideration, particularly in addressing the impact on the ecosystem, when aiming to reduce environmental impacts in the life cycle of silicon solar panels. Our results have also indicated that transportation significantly impacts resource protection, accounting for 15 % of the total impacts in this category, with lesser yet notable contributions to ecosystems and human health. The implications of this work suggest a need for stringent policies to fabricate complete solar photovoltaic modules in Mexico to reduce the environmental burden caused by transportation. Additionally, the insights from this study offer a gateway for the Mexican government to reform current energy transition policies by including multiple recycling scenarios for solar photovoltaic systems, ultimately leading to sustainable growth in this market.