Coal Pollution Hurts Solar Panels, Just Like Your Lungs

A recent study from UK researchers highlights a previously underappreciated impact of coal power plants on solar energy generation. Emissions from coal plants not only pollute the air and harm human health but also reduce the efficiency of nearby solar panels. This occurs both through coal dust settling on panel surfaces, which diminishes their ability to convert sunlight into electricity, and through aerosols suspended in the atmosphere that block sunlight before it reaches the panels. The study estimates that aerosols caused a global reduction in solar electricity output of 5.8% in 2023, equivalent to the output of 18 medium-sized coal-fired power stations. The research, conducted by teams at the University of Oxford and University College London, used satellite data to analyse over 140,000 solar installations worldwide. They found that solar arrays located near coal power plants suffered significantly greater energy losses due to aerosol interference, with China being a particularly affected region. In China, where coal and solar capacity have expanded alongside each other, solar panel output was reduced by 7.7%, with nearly a third of this loss attributed directly to coal emissions. This finding underscores a direct conflict between fossil fuel use and renewable energy generation, challenging the notion that solar power effectiveness can be judged solely by installed capacity. In the United States, the impact of coal-related aerosols on solar panel performance is less severe but still notable, with losses estimated at around 3.1% in 2023. This lower figure is partly due to less frequent co-location of coal and solar facilities compared to China. The study suggests that stricter emissions controls and the retirement of outdated coal power plants could mitigate these losses. The US Department of Energy has previously outlined plans to repurpose retired coal sites for renewable energy projects, signalling a pathway to reduce the negative interactions between coal pollution and solar power. The implications of these findings are significant for the global energy transition. They reveal that continuing to operate coal power plants not only exacerbates public health and environmental issues but also directly undermines the performance of renewable energy infrastructure. As the world seeks to expand solar capacity to meet climate goals, addressing the pollution from coal plants will be critical to maximising the benefits of clean energy technologies. The study calls for urgent action to phase out coal in favour of cleaner alternatives to ensure the full potential of solar power can be realised.