Solar panels are a tremendous and growing renewable resource, but how efficient they are is a major issue and concern. Photovoltaic cells can struggle with picking up the sun’s rays based on position and cloud cover. Even when the sun is beaming right into the solar cells, they can overheat and not absorb as much. Another significant problem is that air pollution particles can build on the panels and hinder absorption.
Efficiency still hovers below the 50 percent mark in solar panels. The record currently sits at 46 percent with direct sunlight in France and 34.5 percent with indirect sunlight in New South Wales. That’s still remarkably low and since the sun obviously doesn’t shine all the time, it’s a resource that can’t be relied on entirely.
Performance suffers even more when airborne materials accumulate on the solar panels. Duke University engineers teamed up with Indian scientists to figure out just how much atmospheric particulate matter affects energy generation. The university’s professor of civil and environmental engineering, Michael Bergin, was amazed at how dirty panels were at the Indian Institute of Technology-Gandhinagar.
After cleaning the panels every few weeks, Bergin reported that a “50-percent jump in efficiency each time the panels were cleaned after being left alone for several weeks.” For the most part, the filth on these panels was from natural dust. Eight percent of the grime, however, was from man-made pollutants.
While that doesn’t seem like a big deal at first, Bergin warns that even partial blockage from these particles can rapidly deteriorate performance. Even worse, this smog is harder to clean off solar panels. The more these panels need to be cleaned, the higher the chance there could be damage on these panels to further performance downgrades.
Since this manmade pollution can impact solar absorption at such a high level, it certainly impacts photovoltaic cell performance just being in the air. Since this pollution is so heavy in places in China and India, there can be up to 25 percent loss of potential solar energy production each month. That’s assuming these panels are cleaned every month. If not, that number can jump to 35 percent after two months.
How significant are these findings? Bergin explains that China alone can lose “tens of billions of dollars” annually and “more than 80 percent of that coming from losses due to pollution.” To put more numbers and perspective behind it, the atmospheric particulate matter can affect around 780 megawatts of solar energy in India and around 7,400 megawatts of solar energy in China.
Both countries are doing their part to eliminate smog in the air. India is planning to sell electric vehicles exclusively by 2030 while China could be getting bikes that can filter out pollution while people ride them. Hopefully more projects and rules will be implemented to continue pushing out smog in the air to keep these solar panels as efficiently as possible.