Maximising environmental savings from silicon photovoltaics manufacturing to 2035

Abstract

The silicon photovoltaics market is transitioning from the incumbent passivated emitter rear cell to the higher efficiency tunnel oxide passivated contact technology and it is crucial to understand the environmental impact of this change. Here, we conduct life cycle assessment to compare both technologies quantitatively and identify environmental savings in 15 of 16 environmental impact categories for tunnel oxide passivated contact. This includes a 6.5% reduction in carbon dioxide equivalent emissions, per watt peak at the expense of 15.2% increase in metal resource use, for photovoltaic modules manufactured in China and transported to central Europe. A critical factor in photovoltaics manufacturing is the carbon intensity of the electricity mix. We model the impact of photovoltaics production across different global regions, incorporating future electricity mix scenarios and a projection for photovoltaics deployment. Our model provides a forecast of the environmental impact of global photovoltaics manufacturing and identifies a potential reduction of 8.2 gigatonnes of carbon dioxide equivalent emissions by 2035, depending on manufacturing location.