- The self-healing coating can repair small cracks in solar glass, increasing strength sevenfold.
- The coating can reduce the weight of solar glass by up to 40%.
- The team is working to apply the coating to full-sized solar panels.
- The new technology has the potential to reduce the raw materials and energy required for solar panel manufacturing.
German researchers have recently unveiled a special self-healing coating that can repair tiny cracks in solar glass, reducing its weight by up to 40% while increasing its strength to seven times the original. This technology was developed by the solar company EXXERGY, based in Gräfelfing, and its subsidiary EXXOSQEL. To achieve this result, the company collaborated with the Fraunhofer Institute for Silicate Research ISC in Würzburg. This innovation could also lead to a 30% reduction in the weight of solar panels. According to the team's report, laboratory tests have shown encouraging results.
The coating increased the strength of glass samples that are 0.08 inches (2 mm) thick by four times. Meanwhile, samples that are 0.04 inches (1 mm) thick exhibited a sevenfold increase in strength compared to untreated non-reinforced glass. The team is currently working to adapt the coating for use on full-sized solar panels.
Strength Enhancement and Application of the Coating
Thomas Sauer, Managing Director of EXXOSQEL, stated, "The transition from laboratory samples to large solar modules requires extensive expertise in material synthesis, application technology, and module manufacturing." Glass is a key component of solar panels as it protects solar cells and other electrical components from weather conditions while allowing sunlight to pass through. The weight of glass accounts for over 80% of the total weight of solar panels. Traditional solar panels typically weigh between 2.3 to 2.7 pounds per square foot (11 to 13 kilograms per square meter).
However, heavier designs can reach up to 3.3 pounds per square foot (16 kilograms per square meter). Using thinner glass may reduce the weight of solar panels but simultaneously increases the risk of damage. Manufacturers typically strengthen glass through thermal treatment, which makes it more difficult for cracks to propagate. However, when the glass thickness is reduced to 0.08 inches (2 mm) or thinner, traditional thermal treatment becomes challenging.
The new coating developed by the German team addresses this issue by forming chemical bonds within the cracks. According to EXXOSQEL, its material creates a three-dimensional (3D) composite structure that establishes covalent bridging at the molecular level. Sauer added, "Specifically, we create a three-dimensional cross-linked composite from multiple components, with the matrix forming covalent bridges in the micro-cracks after the coating is applied." These chemical bonds increase the energy required to break the glass, making thinner glass sheets stronger. EXXOSQEL anticipates that reducing the glass mass by 40% could lead to an overall weight reduction of 30% for certain solar panels.
Production and Technology Readiness Level
The team's current goal is to make the coating suitable for mass production. The Fraunhofer ISC is assisting in producing the coating in batches of up to 100 liters (26.4 gallons). The institute is also working to automate the coating process so that manufacturers can integrate it into existing production lines. Meanwhile, EXXERGY is collaborating with the Fraunhofer Center for Silicon Photovoltaics CSP to test the coating on larger glass panels and solar modules. According to EXXOSQEL, this development is nearing Technology Readiness Level 6 (TRL 6), indicating that a model or prototype has been demonstrated in a relevant environment.
Sauer explained the significance of this progress: "This means we have successfully produced an initial prototype under conditions close to actual application and are conducting stress tests." Their next goal is to reach Technology Readiness Level 7. This category involves demonstrating the technology in an operational environment. If successful, this coating could reduce the raw materials and energy required for solar panel manufacturing.
EXXOSQEL will showcase a demonstration of this technology at Glasstec in Düsseldorf in 2026. The event is the world's leading international trade fair for the glass industry and will take place from October 20 to 23.
Item Specification Glass Thickness 0.08 inches (2 mm) Strength Increase Four times Weight Reduction 40%
Impact of the New Coating Technology on the Solar Industry
The development of this new technology holds significant implications for the solar industry. The self-healing coating not only enhances the strength of the glass but also significantly reduces its weight, which is crucial for improving the efficiency of solar panels and lowering transportation costs. With increasing environmental awareness, reducing the consumption of raw materials and energy during the manufacturing process aligns with sustainability demands. If this technology can be successfully applied to mass production, it could transform market approaches to the design and manufacturing of solar panels, driving further innovation in the industry.