NREL's laser technology simplifies solar module recycling

Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have developed a new method using femtosecond lasers to create glass-to-glass welds in solar modules, significantly simplifying the recycling process. This innovation replaces the traditional use of plastic polymer sheets, which complicates recycling efforts.

By eliminating polymers and employing laser welds, the solar panels can be shattered at the end of their lifespan, allowing for easy recycling of glass and metal components, and reusing silicon. David Young, senior scientist and group manager at NREL, emphasized that polymers are a major obstacle in current recycling processes. "Most recyclers will confirm that the polymers are the main issue in terms of inhibiting the process of recycling," Young noted.

The study, "Towards Polymer-Free, Femto-Second Laser-Welded Glass/Glass Solar Modules," co-authored by NREL's Tim Silverman, Nicholas Irvin, and Nick Bosco, along with Trumpf Inc., introduces a strong, hermetic seal formed by the laser welds applicable across various solar technologies including silicon, perovskites, and cadmium telluride.

NREL's findings, as Young detailed, prove the laser welds are robust, "As long as the glass doesn't break, the weld is not going to break." He added that without polymers, the modules need to be stiffer, a challenge addressed by modifying the embossed features of the glass to withstand static load testing.

The research not only enhances the durability of the modules but also aligns with goals to extend their operational life beyond 50 years and simplify recycling procedures. This innovation represents a significant advancement in solar technology, potentially reshaping module construction and end-of-life processing.

Research Report:Towards Polymer-Free, Femto-Second Laser-Welded Glass/Glass Solar Modules