Breakthrough! Extending the lifespan of solar panels to 50 years using lasers

Recently, the National Renewable Energy Laboratory (NREL) under the US Department of Energy has made a revolutionary breakthrough by developing a concept validation method aimed at completely removing polymers from solar panel manufacturing, thereby achieving more efficient and environmentally friendly recycling.

Solar panels have always been praised for their recyclability. However, the thin plastic layer used in the manufacturing process poses challenges that hinder the effective recovery of valuable materials such as silicon and silver.

To solve this problem, NREL's research team has taken a different approach and proposed an innovative solution of directly implementing glass to glass welding in solar cells.

The core of this solution lies in utilizing infrared femtosecond laser technology. By precisely controlling the laser pulse, energy is focused on a specific area of the solar panel in an extremely short amount of time, forming a sturdy and durable glass to glass weld. It is worth mentioning that femtosecond laser technology has been widely applied in the field of medical ophthalmic surgery, such as cataract surgery, and its safety and reliability have been fully verified.

Through laser welding, the demand for plastic laminates in solar panels is completely eliminated, greatly simplifying the recycling process. After the lifespan of the battery panel, these modules made by laser welding can be easily broken, and the glass and metal wires inside can be smoothly recycled, while the silicon material can also be reused.

"Most recyclers generally believe that polymers are the main problem that hinders the recycling process. The emergence of our technology undoubtedly brings new possibilities for the recycling and utilization of solar panels," said David Young, senior scientist at the Efficient Crystal Photovoltaic Group of the NREL Department of Chemistry and Nanoscience.

This research result has been published in the IEEE Journal of Photovoltaics. The research team pointed out that laser welding technology has a wide range of applicability, not only suitable for silicon materials, but also can be used in combination with various materials such as perovskite and cadmium telluride. Due to the highly focused nature of the laser, the heat generated is limited to a very small range and will not cause damage to the battery material. Meanwhile, the strength of the welds inside the glass is equivalent to that of the glass itself, ensuring the long-term stability and durability of the module.

Young further explained, "As long as the glass itself is not cracked, there will be no problems with the weld seam. Moreover, due to the absence of polymers between the glass sheets, the hardness of the welding module has been significantly improved. Our research shows that by appropriately installing and modifying the embossing characteristics of rolled glass, the welding module can become sufficiently hard to meet the requirements of static load testing."

In the past, researchers have attempted to use nanosecond lasers and glass frit fillers for edge sealing, but the results were not ideal. The brittleness of the welds makes them unsuitable for outdoor module design. In contrast, the femtosecond laser welding technology developed by NREL achieves excellent sealing strength at extremely low cost, providing strong technical support for the recycling and utilization of solar panels.

This study is supported by the Durable Module Materials Alliance, which is committed to extending the lifespan of solar panels to 50 years or even longer. Through NREL's innovative laser technology, we are expected to achieve more efficient and environmentally friendly recycling of solar panels in the future, contributing to the sustainable development of renewable energy.

Source: OFweek