According to scientists from Macquarie University, solar cell manufacturing and recycling could become more convenient due to a surprising discovery involving the use of commercial microwaves.
Typically, the process of making solar panels involves a heating technique called “annealing,” which requires temperatures above 500°C. Traditionally, this was accomplished using ovens. However, a study published in Applied Physics Letters reveals that microwaves are not only faster and more energy-efficient for annealing, but they also facilitate easier disassembly and recycling of the panels.
The reason behind this lies in the fact that microwaves heat specific substances, such as the silicon in solar panels, without significantly affecting the surrounding materials. Dr. Binesh Puthen Veettil, the lead author of the study, explains that this method simplifies the process, as there is no need for meticulous cleaning.
Additionally, the microwave annealing process presents significant benefits for recycling. Currently, the recycling of solar cells is an energy-intensive procedure that involves crushing the panels and heating them to extremely high temperatures to extract valuable elements. Unfortunately, this method damages some reusable components, particularly the glass covering on top of the panel, which accounts for most of its weight.
However, microwaving the silicon specifically softens the plastic layer beneath the glass, allowing for easy removal without damaging the glass. Consequently, the glass can be reused, making the recycling process more economically viable.
Furthermore, microwaving plastic for recycling purposes eliminates the need for high temperatures and additional chemicals. At present, this technique is limited to solar panels that fit inside commercial microwaves, while initial research involved a laboratory microwave acquired from a US company.
As part of the modification process, these microwaves were adapted locally to withstand the extreme annealing temperatures involved, enabling the swift transition from room temperature to 500°C in just two seconds.
The researchers have filed a patent application for this recycling method and are currently exploring ways to enhance and commercialize it. With the potential for industry collaboration and funding, the aim is to scale up the process, ensuring that microwaved solar panels are both environmentally sustainable and financially viable.
By meeting these criteria, profitable recycling centers may naturally emerge and contribute to an organic growth in the market.
