Prof Alison Walker, Physics is one of 6 academic coauthors of this report.

Small-scale solar includes installations on domestic rooftops and balconies, and commercial, industrial and public buildings. The UK Government’s Solar Roadmap calls for a ‘rooftop revolution’, with a total solar target of 45 to 47 gigawatts by 2030, compared to 18 gigawatts in 2025. In the UK, solar made up 10% of renewable generation in 2024, up from 0.2% in 2010.

The briefing's key messages for policymakers are that while the UK Government does not expect to compete in large-scale manufacturing of conventional silicon PV, it has identified potential roles in associated electrical equipment, alongside research into emerging technologies.

This report builds on the influential Solar Commission report Walker chaired in 2019 in that both reports provide insights from academic research and leading businesses to examine innovation in cell technology, applications and storage.

The report is central to Walker’s research on perovskite solar cells, an exciting new technology, possessing greater efficiencies whose manufacture can be done cheaply and with a low energy budget. However, the cells have much shorter lifetimes than the dominant solar technology based on silicon. This research focusses on understanding solar cell degradation through the use of physics guided machine learning in interpreting experimental measurements. Its aim is a model that runs fast enough to update at the same rate as changes occur, so can be operated effectively as a digital twin. It is readily adapted to outdoor or operational monitoring of cell degradation, including possible implications for long-term energy-yield prediction.

This approach has applications to many devices such as batteries and sensors.

References

• Alison Walker’s website https://people.bath.ac.uk/pysabw/ from which the Solar Commission Report can be downloaded

• S G McCallum et al Bayesian parameter estimation for characterising mobile ion vacancies in perovskite solar cells J. Phys. Energy 6 015005 (2024)