A Life Cycle Perspective on Monofacial and Bifacial Photovoltaic Module Sustainability and Environmental Offsets

The energy sector is estimated to account for approximately 80% of total greenhouse gas emissions in Europe, making its shift to renewable and sustainable sources a central pillar of the European Green Deal. This commitment is reflected in the ambitious targets set by the RED III and the Climate-Neutral and Smart Cities initiatives for 2030. Among the various renewable energy options, photovoltaic systems stand out as a promising solution due to their scalability, declining costs, and potential for decentralized generation. However, the production process involves energy-intensive activities, the use of scarce or hazardous materials, and the creation of waste that needs to be carefully managed. In this study, an analysis of published Environmental Product Declarations (EPD), third-party verified life cycle assessments conforming to ISO 14025:2006, was conducted to evaluate the average environmental profiles of commercially available photovoltaic module designs. Both monofacial and bifacial PV modules were assessed, with a focus on the differences in solar cell structures and semiconductor materials. To support decision-makers and industry experts, it is crucial to understand how installation parameters and environmental conditions influence the carbon emission offsets time and overall environmental performance of solar installations. In particular, this analysis investigated the effects of tilt angle, azimuth orientation, and bifacial gain under controlled conditions, tracking how these factors alter the environmental profile based on simulated energy outputs over a 25-year service life. The results indicate a 16% reduction in environmental impact between the worst-case and best-case tilt angle scenarios, and a decrease of around 25% when comparing south-facing to west-facing orientations. Moreover, a 20% enhancement in electricity generation achieved through bifacial gain was estimated to correspond to a 16% reduction in the associated environmental impact. Finally, the greenhouse gas (GHG) emission payback time for PV modules alone was found to be approximately one year.