According to David Young, the author of the study, recyclers often consider polymers as a significant obstacle in the recycling process. To address this issue, scientists conducted an experiment using a femtosecond laser, which uses short pulses of infrared light to melt glass together and create a strong, hermetic seal. The glass weld produced by the laser can be applied to any type of solar technology, including silicon, perovskites, and cadmium telluride, as the heat is concentrated near the laser focus.
NREL’s research has indicated that glass/glass welds are just as strong as the glass itself. This means that if the glass does not break, the weld will remain intact. While eliminating polymers between glass sheets makes welded modules stiffer, proper mounting and modifications to glass features can ensure that these modules pass static load testing.
The femtosecond laser welding technique is a groundbreaking approach to creating glass/glass welds for solar modules. Previous attempts using nanosecond lasers and glass frit fillers resulted in brittle welds unsuitable for outdoor module designs. In contrast, femtosecond laser welds offer superior strength and hermetic sealing at a reasonable cost, opening up new possibilities for the longevity and recyclability of solar modules.
Young believes that this study points towards a promising direction for future research in extending the lifespan of solar modules beyond 50 years and making recycling easier. Despite being a high-risk endeavor, this experiment highlights the potential benefits of utilizing advanced technologies in addressing pressing sustainability issues related to renewable energy production and waste management.