Pioneering research led by Northumbria University shows how the renewable energy sector can scale-up the production of solar energy technology while further reducing environmental impacts.

As solar energy rapidly expands to meet urgent climate targets and increasing demand for electricity, the key challenge is to ensure that this transition is not just scalable but sustainable.

Published in Nature Communications, the study demonstrates that solar panels – which are already a powerful tool for reduced carbon dioxide emissions – will become even more environmentally friendly as the industry adopts next-generation technology.

The study reveals an encouraging trend: improvements in the efficiency of solar cells can simultaneously drive environmental benefits that extend beyond just reducing greenhouse gas emissions.

The research is a collaboration between Northumbria and the Universities of Birmingham, Oxford, and Warwick. The work involves using life cycle assessment to quantify the environmental impact of photovoltaics from extraction of raw materials out of the ground to the production of state-of-the-art silicon solar panels that will dominate the market up to 2035. This timescale is critically important as we take decisive action towards Net Zero and significantly scale-up our demand for electricity across the world.

First authored by Bethany Willis, a ReNU PhD student at Northumbria University, and directed by Neil Beattie, Professor of Energy Innovation at Northumbria University, the research reveals that the composition of the electricity mix used to manufacture solar panels strongly affect the environmental impact of production. Realistic decarbonisation of global mixes offers savings of up to 8.2 gigatonnes of equivalent carbon dioxide emissions. To put in context, that represents approximately 6.3% of the total remaining carbon budget to stay on track with the Paris Agreement and limit global warming to 1.5 °C.

“Solar photovoltaics is a critical technology that can be used globally now to significantly reduce greenhouse gas emissions and create energy security,” said Professor Neil Beattie. “This is especially important as our demand for electricity soars over the next decade driven by applications in transport, heating and digital infrastructure for AI.

“As we scale-up photovoltaics to multi-terawatt levels to meet this demand, it’s important that we do so sustainably. Our research demonstrates that significant savings in environmental impact – including carbon dioxide emissions – are possible through manufacturing.

“More specifically, we find that this impact is sensitive to the composition of the electricity mix where the solar panels are made and we should work to decarbonise this as much as possible.”

Professor John Murphy, co-author and Chair of Electronic Materials at the University of Birmingham, said: “Silicon-based photovoltaic technologies have immediate relevance to the UK and already play a major role in our strive for Net Zero. This groundbreaking study originates from a new collaboration between four leading UK University research groups who intend to work on all aspects of sustainability in the photovoltaics supply chain from raw materials through to end-of-life.”

Sebastian Bonilla, Associate Professor of Materials Science at The University of Oxford and co-author, added: “We are at a critical moment where solar power is rapidly scaling to become a significant portion of global electricity generation. This work uniquely identifies the environmental impacts of the ongoing solar energy revolution, helping us guide the choices of materials, technologies, and manufacturing locations that will minimise harm while maximising the benefits of terawatt green electricity.”

While carbon dioxide emissions remain the most widely considered environmental impact, the study quantifies 16 different environmental impact categories.

An important impact from the work is that industrialists and policy makers can use it to pinpoint where further innovation is required. For example, next-generation technology reduces climate impact by 6.5% but increases critical mineral depletion by 15.2% due to higher silver consumption in the electrical contacts to the solar cell. This motivates research and development into alternative materials, such as copper. It also emphasises the need to avoid simply shifting environmental burdens from one category to another but rather consider sustainability as a system problem.

The study forecasts that solar panels installed by 2035 could avoid at least 25 gigatonnes of CO₂ emissions compared to conventional power sources in less than half of their operational life.

Study co-author, Dr Nicholas Grant, Associate Professor, at The University of Warwick said: "Terawatt‑scale photovoltaic manufacturing demands a sharper focus on its full environmental footprint. Our paper shows how targeted improvements across the supply chain can deliver sustainable manufacturing at the terawatt-scale, avoiding gigatonnes of manufacturing‑related CO₂ emissions if installed by 2035, while supporting rapid global deployment”.

As Professor Beattie also notes: “Even when manufacturing impacts are considered, solar photovoltaics remains one of the lowest-impact and most sustainable electricity generation technologies available over its whole life cycle and we should concentrate on deploying it at scale, now.”