Aerosol Particles, Partly from Coal Pollution, Block Sunlight and Reduce PV Solar Output: New Study Quantifies the Effects

      The University of Oxford and University College London (UCL) recently conducted and published new research assessing and mapping more than 140,000 solar photovoltaic (solar PV) installations around the world. The results were published in the journal Nature Sustainability. They used satellite and atmospheric data on air pollution to calculate how much sunlight is lost from pollution aerosol particles and how this reduces electricity generation. They found that pollution from coal-fired power plants “significantly reduces” the energy output of solar PV installations, particularly where the coal and solar facilities are close together. They found that the aerosol particles suspended in the air reduced global solar electricity by 5.8% in 2023. They compared the losses of electricity output to the level of new output for the year for newly built facilities and found that the lost output (74TWh) was nearly one-third the new output average for the years 2017-2023 (246.6TWh).

     According to Euro News:

“Coal plants emit fine pollution particles that scatter and absorb sunlight, which reduces the amount that reaches nearby solar panels. Dr Song explains that air pollution doesn’t just block sunlight, but also changes clouds which can cut solar power even further.”

“That means the real impact is likely to be bigger than we’ve measured, so we may be overestimating how much solar power can contribute to reducing emissions if we do not get pollution from coal power under control,” he adds.

“This effect was particularly evident in China, where solar and coal capacity have expanded in parallel and are often co-located. Regions with high coal capacity aligned closely with areas experiencing the greatest solar PV losses.”

     The coal plant image given in the Euro News article is one that is close to where I live in Southeast Ohio, although I am happily upwind of it. I may even be powered by it, I am not sure.

     China is the world's largest solar energy producer as well as the world’s largest coal energy producer, and the co-location of these plants there has especially blocked solar output. This is likely a factor why Chinese solar efficiency is lower than the global average. The researchers found that Chinese solar output dropped by 7.7% due to aerosols compared to the global average of 5.8%. They estimate that 29% of aerosol-related solar PV losses in China come specifically from coal-fired power plants.

     Phys.org explains that the global solar output losses in 2023 due to aerosols amount to 111TWh, equivalent to the output of 18 medium-sized coal-fired power plants. Stricter emissions standards from coal plants and retrofitting plants with ultra-low emissions (ULE) technologies have led to less aerosol-related losses in China:

“Aerosol-related solar PV losses declined by an average of 0.96 TWh per year (−1.4% annually) between 2013 and 2023.”

     This suggests that aerosol losses were previously above 10% in China.

     Satellite imagery and machine learning were employed in the study. Author Professor Jan-Peter Muller (Mullard Space Science Laboratory at UCL) said:

"Global satellite imaging enabled us to map the inexorable rise of cheap non-polluting solar power during daylight hours. In the near future, we will be able to observe the impacts of dust and smoke particles on reducing solar energy at Earth's surface in real-time every 10 minutes from geostationary satellites spanning Earth."

     The results show that modeled solar output is often overestimated due to not taking the effects of aerosols into account.

  

References:

 

Blocked sunlight and changing clouds: How coal pollution is damaging our solar potential. Liam Gilliver. Euro News. May 15, 2026. Blocked sunlight and changing clouds: How coal pollution is damaging our solar potential

Coal pollution is cutting solar power output worldwide, study finds. Science X staff. Phys.org. May 15, 2026. Coal pollution is cutting solar power output worldwide, study finds

Coal plants persist as a large barrier to the global solar energy transition. Rui Song, Feng Yin, Jan-Peter Muller, Adam C. Povey, Basudev Swain, Chenchen Huang & Roy G. Grainger. Nature Sustainability. May 15, 2026. Coal plants persist as a large barrier to the global solar energy transition | Nature Sustainability