Coal emissions slash global solar potential by 500 terawatt-hours annually
New research indicates that sulfur dioxide from coal burning accounts for nearly half of aerosol-related solar losses, with China experiencing a 7.7 per cent reduction in output while the United States sees a 3 per cent impact.
A study published in Nature Sustainability has quantified the extent to which coal pollution undermines global solar power generation, finding that aerosols reduce potential output by more than 500 terawatt-hours annually. The research, conducted by a team in the United Kingdom, utilises a new global inventory of solar facilities constructed through AI-analysed satellite imagery and crowdsourced records to map facility sizes and locations against location-tagged weather data.
In 2023, aerosols accounted for approximately six per cent of lost solar production worldwide, a figure equivalent to the annual output of 84 coal-fired power stations with a one-gigawatt capacity each. While clouds were responsible for over 20 per cent of potential losses, the study highlights that coal-derived emissions, particularly sulfur dioxide, are a major driver of the remaining aerosol-related reductions, accounting for nearly half of the aerosols analysed.
The impact of these emissions is geographically uneven, closely mirroring the distribution of coal-fired power capacity. In China, aerosols reduced solar production by 7.7 per cent, with coal burning attributed to 30 per cent of these losses. This spatial correlation suggests that pollution from coal plants directly offsets the country’s annual growth in solar capacity, although recent improvements in air quality due to the retirement of polluting plants and the installation of high-efficiency facilities have begun to mitigate this effect.
Conversely, the United States experienced a 3 per cent loss in solar output due to aerosols. This lower impact is largely attributable to the geographical separation of infrastructure, with most US solar production occurring in the south and west, while coal plants are concentrated in the east and northeast. Researchers noted that carbon-rich material from fossil fuels accounts for another 18 per cent of the aerosols, but coal remains the primary pollutant affecting solar productivity.
Between 2018 and 2023, global solar capacity growth added an average of 250 terawatt-hours of potential annual power, yet 75 terawatt-hours of this new capacity was lost to aerosols. The study concludes that coal is the only power source that actively diminishes the productivity of solar energy, its primary competitor, providing a further economic impetus to accelerate the transition away from coal-fired generation.
