Coal Pollution Hurts Solar Panels, Just Like Your Lungs

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US President Donald Trump is determined to breathe new life into the nation’s aging fleet of coal power plants, regardless of the harm to human lungs and the impacts on local ecosystems, too. Why does the American President hate Americans so much? Who knows!? Regardless, a new study from the UK makes yet another case for ditching coal. In addition to polluting the air people breathe, emissions from coal power plants are reducing the effectiveness of nearby solar panels — and washing doesn’t work.

Solar Panels And The Coal Dust Factor

Before we get to the emissions from coal power plants, let’s consider coal. Airborne coal dust from mining operations is a well-known contributor to poor health outcomes and economic malaise in communities that share space with the coal industry. Emissions from coal power plants are also responsible for thousands of premature deaths every year, so it’s somewhat of a mystery why the Commander-in-Chief is determined to force more coal upon members of the breathing public, especially when more healthful, more economical energy resources exist for the taking.

Be that as it may, when dust of any kind settles on the surface of solar panels, it reduces their ability to convert light into electricity. In arid regions where natural washing from precipitation is infrequent, washing trucks or robotic washing systems can keep the panels clean, although that adds a maintenance expense. Washing can also add yet another burden to stressed water systems.

Solutions are emerging. New solar coatings can help remove dust more efficiently, and a research team based at the Massachusetts Institute of Technology has proposed a waterless system based on electrostatic induction. That would solve the water resource issue, though the “electro” part of electrostatic underscores the foundational problem: electrified cleaning systems skim solar energy off the top of a solar power plant, reducing the amount of power available for the grid.

No Coal Power Plants = More Efficient Solar Panels

Settled dust is not the only problem. Emissions from coal power plants can also remain suspended in the air above solar panels as aerosols, where they obstruct sunlight.

UK researchers at the University of Oxford and University College London have been studying how solar panels are impacted by aerosols generally, and coal aerosols in particular. Using satellite data, the research team mapped more than 140,000 solar installations around the world. They cross-referenced those facilities with atmospheric data and calculated the cumulative impact of all aerosols on electricity generation from those facilities.

“They found that aerosols – tiny particles suspended in the air – reduced global solar electricity output by 5.8% in 2023,” noted the University of Oxford.

“This is equivalent to 111 terawatt-hours (TWh) of lost energy – the amount generated by 18 medium-sized coal-fired power plants,” the school added for emphasis.

The researchers further identified a pattern in which solar arrays closest to coal power plants lost significantly more energy due to aerosol interference. “This effect is particularly evident in China, where solar and coal capacity have expanded in parallel and are often co-located,” the research team elaborated. “Regions with high coal capacity aligned closely with areas experiencing the greatest solar PV losses.”

The researchers estimate China’s loss of solar panel output from all aerosols combined at 7.7%, with coal power plants accounting for about 29% of that amount.

“This highlights a previously unrecognised interaction between fossil fuel use and renewable energy, where emissions from one system directly reduce the performance of the other,” the University of Oxford emphasized in a press statement.

“These results show that the effectiveness of solar power cannot be judged by installed capacity alone,” the school added. “Even as solar expands rapidly, interactions with the existing fossil fuel system can reduce the amount of clean energy actually delivered.”

Meanwhile, Over In The USA

The full study has been published in the journal Nature Sustainability under the self-explanatory title, “Coal plants persist as a large barrier to the global solar energy transition.” The study indicates that stricter emissions controls can mitigate the impact of coal power plants on nearby solar panels, but the overall takeaway is that coal needs to go.

“Looking forward, the physical interaction between coal-based aerosols and solar PV performance is likely to become an increasingly critical constraint on the global energy transition,” the researchers emphasize.

The researchers also note that solar arrays in the US are less exposed to aerosol-related limitations from coal emissions than their Chinese counterparts, because co-locating coal and solar facilities is less common here than in China. The researchers assess that aerosol-induced losses from solar panels came to about 3.1% in the US in 2023, substantially lower than the 5.8% they calculated for global losses.

Still, a 3.1% loss is still a 3.1% loss, and it is a partly preventable loss at that. All you have to do is shutter old, outdated coal power plants and replace them with clean, modern renewable energy. When Trump took office in January last year, the outgoing staff of the US Department of Energy even provided him, and the general public, with a set of “Coal-to-X” roadmaps focusing on repurposing the sites for wind and solar energy plus storage, with nuclear energy, data centers, and various manufacturing ventures among other alternatives.

“Retired and retiring coal power plants provide an opportunity for redevelopment to new energy infrastructure,” noted the Energy Department’s Pacific Northwest National Laboratory on January 14, 2025. “Existing land and facilities at the power plant site can be repurposed, such as electricity infrastructure for connections to the grid as well as administrative buildings and parking lots.”

Of course, that went out the window when Trump took office just six days later. He can personally take credit for pushing more pollution into the air, including fresh bursts of airborne mercury and sulfur dioxide, while raising costs for electricity. The UK finding adds yet another twist to the sorry tale of what passes for federal energy policy these days.

Then there’s the impact on water resources, but who’s counting? Trump sailed into office with the support of 77 million voters who chose the wrong person for the job, but we all have to breathe the same air. If you have any thoughts about that, drop a note in the comment thread. Better yet, find your representatives in Congress and let them know what you think.

Photo (cropped): Coal power plants produce aerosols that hover above solar panels, diffusing light and reducing the solar conversion efficiency of nearby solar arrays (solar power plant on a landfill courtesy of US Department of Energy).