In the quest for sustainable energy solutions, researchers at the University of Turku, in collaboration with Aalto University and Wageningen University, have developed a bio-based ultraviolet (UV) protection film for solar cells. By incorporating nanocellulose treated with red onion skin extract, they have created an innovative and eco-friendly alternative to traditional petroleum-based protective films, such as polyvinyl fluoride (PVF) and polyethylene terephthalate (PET). This breakthrough not only enhances solar panel durability but also reduces reliance on fossil fuel-derived materials.
Nanocellulose: A Sustainable Base for Solar Protection
To begin with, the key component of this new UV protection film is nanocellulose, a material derived from plant cellulose broken down into nanoscale fibers. By treating this nanocellulose with red onion skin extract, the researchers developed a film capable of blocking 99.9% of UV radiation up to 400 nanometers. As a result, this bio-based film significantly outperforms conventional PET-based UV filters, making it a strong candidate for future solar applications.
Maintaining Transparency and Efficiency
One of the most crucial aspects of solar cell protection is maintaining transparency, as excessive filtering can reduce energy absorption. Fortunately, the onion-dyed nanocellulose film addresses this concern effectively. While it blocks harmful UV rays, it still allows over 80% light transmission at longer wavelengths (650–1,100 nanometers), which is essential for efficient energy conversion. Additionally, the film has demonstrated remarkable durability. In tests simulating approximately one year of outdoor sunlight exposure in central European climates, the film maintained its protective properties even after 1,000 hours of artificial light exposure. This durability suggests that the material could be a long-term solution for improving solar panel performance.
Comparing Alternative Bio-Based UV Blockers
Beyond red onion extract, the study also explored other bio-based UV-blocking agents, including lignin and iron ions. However, when comparing their effectiveness, researchers found that the red onion extract-treated film delivered the best results. Not only did it provide superior UV protection, but it also maintained higher transparency, making it an ideal candidate for advanced solar technologies. These findings could open doors for various solar cell applications, including dye-sensitized, perovskite, and organic photovoltaics. Furthermore, because the material is biodegradable, it could support the development of environmentally friendly solar cells for emerging applications like food packaging sensors.
A Step Toward Sustainable Solar Technology
Ultimately, this research marks an important step toward greener and more sustainable solar energy solutions. By replacing petroleum-based protective films with biodegradable materials, scientists are helping to reduce environmental impact while enhancing the longevity of solar cells. If further developed, this technology could contribute to the widespread adoption of renewable energy, bringing us closer to a cleaner and more sustainable future.
