Project lead Professor Michael Walls, Professor of Photovoltaics for Power Systems in the university’s Centre for Renewable Energy Systems Technology (CREST), says the three-year-long study, funded by the Engineering and Physical Sciences Research Council (EPSRC), has the potential to “mitigate one of the most serious problems for solar utilities”.

The cost of solar modules – also referred to as ‘solar panels’ – has reduced dramatically over the past few years and it is forecast that more than 40GW will be in use in the UK by 2030.

Solar assets are financed by professional managers who are concerned by the ongoing operational costs of maintenance, which affect power output and the return on investment.

Attention is being drawn to the issues caused by ‘soiling’, a term used to describe the accumulation of dirt, dust, snow, and other particles on the cover glass on solar modules.

This is a serious problem as soiling reduces the amount of light reaching the solar cells.

Soiling can reduce power output by more than 5% in the UK and is a far more serious problem (up to 50%) in arid, sunbelt regions such as in India and the Middle East.

Polymer-based hydrophobic (water-repelling) anti-soiling coatings have been shown to work in principle, but their durability is not sufficient to withstand 24/7 exposure to environmental stresses or to abrasion damage caused by regular cleaning.

The objective of this research is to develop and test a thin abrasion-resistant inorganic coating.

The researchers hope the coating will reduce modules’ adhesion to soiling and reduce the frequency of costly cleaning cycles.

The coating will be designed to ensure it is capable of being applied at an industrial scale using a chemical process that is compatible with glass manufacturing.

The team predicts that, if the project is successful, the use of the coating will “significantly improve the practical power output of solar modules and will have a worldwide impact”.

Professor Walls commented: “The UK is committed to achieving net zero carbon emissions by 2050.

“This will require a massive shift in the way electricity is generated, away from burning fossil fuels and towards the use of renewable sources such as wind and solar.

“We are thrilled to receive funding for this project through EPSRC. Soiling is a huge problem that limits the power output from solar panels.

“Our plan is to produce an anti-soiling coating that is both effective, durable, and low cost.”

The £1.2 million project is in collaboration with the University College London and will receive input from industrial partners Above Surveying Ltd, NSG Group (UK), Solar Farm Cleaning Ltd.

Professor Ivan Parkin, Dean of the UCL Faculty of Mathematical and Physical Sciences, commented: “We look forward to making the coatings through a process called chemical vapour deposition and to see how they work in practice.

“This is part of a ‘cradle to grave’ study where we synthesise the starting materials, deposit them as thin films, and then test their functional properties.

“A successful coating could go a long way to improve the lifetime efficiency of solar panels, enhancing their effectiveness.”