UNSW research has found that smoke from major bushfires can sharply reduce solar electricity generation, even from more than 150 kilometres away.
The smoke can significantly reduce the amount of electricity generated by solar farms, even when the fires are burning many kilometres away.
UNSW Sydney researchers said better forecasting of smoke movements, more frequent panel inspections and cleaning, and changes to how solar panels operate could help solar farm operators prepare for these events and protect their equipment.
The recommendations follow a study examining the effects of two major Australian bushfires – the 2019-2020 Black Summer fires and Victoria’s 2009 Black Saturday fires.
Using historical weather and satellite data, the researchers modelled how smoke and airborne particles affected solar electricity generation and panel temperatures across south-eastern Australia.
The UNSW’s School of Photovoltaic and Renewable Energy Engineering published the findings. Author Dr Shukla Poddar said the findings highlight the need to look beyond solar farms immediately surrounding a fire and consider where smoke is likely to travel.
“We should start looking into things like trajectory modelling of the smoke and how long and far those smoke particles can be transported,” she said.
“Extreme bushfires are becoming more frequent and intense in several regions, including Australia, California and southern Europe. Their impacts are not confined to the areas where fires burn: smoke from California’s 2020 wildfires reached Europe, while smoke from Spain’s 2025 fires travelled as far as the UK and northwestern Europe.
"Although this particular study is based on two extreme bushfires in Australia, the same method and analysis can be done for other parts of the world.”
Solar panels generate electricity by converting sunlight into electrical energy. Smoke and airborne particles can reduce the sunlight reaching the panels, lowering the amount of electricity they produce.
The UNSW study found that the impacts can extend well beyond the immediate fire zone.
During the Black Summer bushfires, the researchers estimated that electricity generation fell by as much as 70% at locations within about 50 kilometres of fire hotspots during several consecutive days.
In regions more than 150 kilometres from hotspots, the study estimated there were still losses of up to 30%.
The effects varied with the severity of the fires and the weather. During the 2009 Black Saturday bushfires, the study estimated lower reductions of generated power of around 18% near fire hotspots and up to 10% in more distant regions.
These figures are modelled estimates rather than measurements from individual solar farms. The researchers were unable to separate smoke-related losses from other factors, such as electricity generation being deliberately limited when the grid did not need all the power available.
Smoke distribution
Researchers recommend combining bushfire information, wind patterns and smoke-trajectory modelling to help predict which solar farms are likely to be affected.
Weather forecasts already help operators anticipate conditions such as high temperatures and strong winds. A similar system for smoke could give them advance warning that airborne particles are heading towards their facilities.
That warning could allow operators to plan inspections, schedule cleaning or adjust the position of panels before smoke arrives.
The study also highlights the importance of panel maintenance, particularly during bushfire periods.
Smoke particles can settle on solar panels, reducing the sunlight reaching their surfaces. If deposits accumulate unevenly, they may also create localised hot spots, where parts of a panel become much hotter than others. Over time, these hot spots can damage cells and reduce their performance.
The study did not model this localised damage directly, so further work is needed to establish how frequently it occurs during bushfires and how much generation it can cost.
Poddar recommends more frequent cleaning when smoke is likely to affect a solar farm, alongside regular thermal inspections to identify unusually hot panels or electrical components.
The paper also recommends better remote monitoring and electrical fault detection, allowing operators to identify temperature anomalies and quickly isolate affected parts of a system.
Managing grass and shrubs beneath panels, maintaining firebreaks and preparing bushfire management plans can help reduce the risk of fires starting or spreading within solar farms.
Many large solar farms use tracking systems that move panels to follow the Sun throughout the day.
Poddar advised operators temporarily adjust those angles during particularly hot periods, such as when bushfires are occurring, rather than always positioning panels for maximum sunlight.
"The aim would be to reduce heat exposure and potentially help loose particles move off panel surfaces. Such adjustments would involve a trade-off since panels may produce less electricity while turned slightly away from the Sun," she said.
The research findings could also inform decisions about where to build future solar farms. Developers could assess the history of nearby bushfires and examine prevailing wind directions and likely smoke pathways before investing in a site.