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.
Data availability
The life cycle assessment data generated in this study are provided in the Supplementary Information and Supplementary Data files. All source data used to create figures are also provided in the Source Data file. Source data are provided with this paper.
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Acknowledgements
The authors gratefully acknowledge financial support for this research from the Engineering and Physical Sciences Research Council in the UK through grants EP/S023836/1 (B.L.W. EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities) and EP/W010062/1 (O.M.R., N.S.B., EPSRC Reimagining Photovoltaics Manufacturing). The work was also supported by the EPSRC Charged Oxide Inversion Layer (COIL) solar cells project (EP/V037749/1 and EP/V038605/1). S.L.P. is supported by a Royal Academy of Engineering Research Fellowship RF-2324-123-197. The authors gratefully acknowledge useful discussions with Prof Caroline Sablayrolles and Dr Claire Vialle in relation to life cycle assessment, as well as Kyle Affleck for their valuable contribution towards uncertainty and sensitivity analysis.
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B.L.W., O.M.R., and N.S.B. conceived and designed the research. B.L.W. and O.M.R. performed the life cycle assessment, analysis and interpretation under the supervision of N.S.B. S.L.P., N.E.G., J.D.M., and R.S.B. supported the analysis and steered the direction of the investigation. S.L.P., N.E.G., J.D.M. and R.S.B. provided technical insights relating to silicon photovoltaics and R.S.B. facilitated data collection relating to tunnel oxide passivating contact solar cells. B.L.W., O.M.R., N.S.B. prepared the manuscript and revised submission; B.L.W, O.M.R, S.L.P, N.E.G, J.D.M, R.S.B, and N.S.B reviewed and commented on the manuscript and the revision.
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Willis, B.L., Rigby, O.M., Pain, S.L. et al. Maximising environmental savings from silicon photovoltaics manufacturing to 2035. Nat Commun (2026). https://doi.org/10.1038/s41467-026-69165-x
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DOI: https://doi.org/10.1038/s41467-026-69165-x
