Submission + - More durable UV coating for solar panels made from red onion skins (zmescience.com)
fahrbot-bot writes: In a lab in Turku, Finland, scientists have found a surprising ally in the fight for sustainable solar energy: the papery red skin of an onion.
Researchers from the University of Turku, in collaboration with Aalto University and Wageningen University, have developed a bio-based UV protection film for solar cells that not only blocks nearly all harmful ultraviolet light but also outperforms commercial plastic films. The key ingredient is a water extract made from red onion skins.
Sunlight can degrade the delicate components in solar panels—particularly the electrolyte inside dye-sensitized solar cells (DSSCs), a type known for their flexibility and low-light performance. To mitigate this, manufacturers typically wrap cells in UV-protective films made from petroleum-based plastics like polyethylene terephthalate (PET). But these plastics degrade over time and are difficult to recycle.
Seeking a greener alternative, the team turned to nanocellulose, a renewable material derived from wood pulp. Nanocellulose can be processed into thin, transparent films that serve as the perfect substrate for UV-blocking compounds.
Their breakthrough came when they dyed these films using an extract from red onion skins, a common kitchen waste. The result was a filter that blocked 99.9% of UV radiation up to 400 nanometers, a feat that outstripped even the PET-based commercial filters chosen for comparison.
In solar cells, preserving visible and near-infrared light is crucial. That’s the part of the spectrum that powers electricity generation. And here, too, the onion-treated filter excelled: it let through over 80% of light in the 650–1,100 nm range—an ideal sweet spot for energy absorption.
Testing under 1,000 hours of artificial sunlight, the CNF-ROE film—short for cellulose nanofiber with red onion extract—held up remarkably well. It exhibited only minor discoloration and preserved the yellow hue of the electrolyte far better than any other filter. Even predictive modeling based on early degradation trends suggested the CNF-ROE filter could extend a solar cell’s lifetime to roughly 8,500 hours. The PET-based filter? Just 1,500 hours.
Google: red onions solar panels
Researchers from the University of Turku, in collaboration with Aalto University and Wageningen University, have developed a bio-based UV protection film for solar cells that not only blocks nearly all harmful ultraviolet light but also outperforms commercial plastic films. The key ingredient is a water extract made from red onion skins.
Sunlight can degrade the delicate components in solar panels—particularly the electrolyte inside dye-sensitized solar cells (DSSCs), a type known for their flexibility and low-light performance. To mitigate this, manufacturers typically wrap cells in UV-protective films made from petroleum-based plastics like polyethylene terephthalate (PET). But these plastics degrade over time and are difficult to recycle.
Seeking a greener alternative, the team turned to nanocellulose, a renewable material derived from wood pulp. Nanocellulose can be processed into thin, transparent films that serve as the perfect substrate for UV-blocking compounds.
Their breakthrough came when they dyed these films using an extract from red onion skins, a common kitchen waste. The result was a filter that blocked 99.9% of UV radiation up to 400 nanometers, a feat that outstripped even the PET-based commercial filters chosen for comparison.
In solar cells, preserving visible and near-infrared light is crucial. That’s the part of the spectrum that powers electricity generation. And here, too, the onion-treated filter excelled: it let through over 80% of light in the 650–1,100 nm range—an ideal sweet spot for energy absorption.
Testing under 1,000 hours of artificial sunlight, the CNF-ROE film—short for cellulose nanofiber with red onion extract—held up remarkably well. It exhibited only minor discoloration and preserved the yellow hue of the electrolyte far better than any other filter. Even predictive modeling based on early degradation trends suggested the CNF-ROE filter could extend a solar cell’s lifetime to roughly 8,500 hours. The PET-based filter? Just 1,500 hours.
Google: red onions solar panels
