A groundbreaking new study reveals a significant and unexpected hurdle for the global solar energy transition: aerosols primarily generated by coal-fired power plants (CFPPs) are dramatically blocking sunlight, consequently reducing electricity production from solar power plants (SPPs) worldwide. This startling finding challenges assumptions about the pace and effectiveness of the clean energy shift.
Titled “Coal Plants Persist as a Large Barrier to the Global Solar Energy Transition,” the research highlights that solar power plant electricity production experienced a 5.8 percent decrease in 2023. This translates to a staggering loss of 111 terawatt-hours (TWh) of electricity, an amount roughly equivalent to the annual output of 18 medium-sized coal-fired power plants.
The problem is further compounded by concurrent growth in both energy sectors. While new SPP installations contributed an impressive average of 246.6 TWh of additional electricity annually between 2017 and 2023, aerosol pollution simultaneously caused existing solar facilities to lose approximately 74 TWh of electricity each year. This alarming statistic means nearly one-third of the additional electricity generated by new solar projects is being negated by pervasive air pollution.
Rui Song, the study’s lead author and a researcher at the University of Oxford’s Department of Physics and University College London’s Space Science Laboratory, emphasized the urgency of this discovery. “The world is witnessing incredibly rapid growth in renewable energy,” Song stated, “but the effectiveness of this transition is proving lower than widely assumed.” He further elaborated that as CFPPs and SPPs develop side-by-side, emissions from coal alter atmospheric solar radiation conditions, directly diminishing the performance of solar power plants.
While aerosols can originate from various sources, including vehicle emissions and natural phenomena like volcanic activity, the study definitively identifies coal-fired power plants as the primary contributor of the particulate matter significantly impacting solar output.
The detrimental effects of aerosol pollution from coal plants are particularly evident in China, the world’s largest solar power producer. In 2023, China generated 793.5 TWh of electricity from SPPs, accounting for 41.5 percent of the global solar total. However, the country’s solar electricity production is estimated to have fallen by 7.7 percent due to atmospheric pollutants. Researchers calculate that roughly 29 percent of China’s total aerosol-related SPP production loss specifically stems from emissions from coal-fired power plants.
Song issued a further warning, suggesting the true impact might be even greater. “Air pollution not only blocks sunlight but also influences cloud formation, which can further reduce solar power plant output,” he added. “This implies that the actual impact is likely larger than what we were able to measure. If pollution from coal-fired power plants remains unchecked, we risk overestimating how much SPPs contribute to emissions reduction.”
To reach these critical conclusions, researchers meticulously mapped and analyzed over 140,000 photovoltaic (PV) solar panel installations worldwide using satellite data. This comprehensive spatial data was then integrated with detailed atmospheric information concerning air pollution levels.
Despite these significant challenges, reports from the energy think tank EMBER indicate a positive overarching trend: solar, wind, and other renewable sources are projected to account for 34 percent of global electricity production by 2025, ultimately surpassing coal’s share. Nevertheless, coal remains a critical, and often primary, energy source in major manufacturing hubs such as China, as well as in numerous developing nations, including those across Southeast Asia and India.
Summary
A new study reveals that aerosols, primarily from coal-fired power plants, are significantly reducing global solar power output. In 2023, solar electricity production worldwide decreased by 5.8%, equating to a loss of 111 terawatt-hours. This loss effectively negates nearly one-third of the additional electricity generated by new solar installations annually, highlighting an unexpected challenge to the clean energy transition.
The research emphasizes that while new renewable energy capacity continues to grow rapidly, its overall effectiveness is being undermined by persistent pollution. China, the world’s largest solar producer, saw its solar electricity production fall by 7.7% due to atmospheric pollutants, with 29% directly attributed to coal plant emissions. Experts warn that the true impact might be even greater, as air pollution also affects cloud formation, thus stressing the urgent need to address coal plant emissions to fully realize solar energy’s potential.
