// Development of a recycling process for perovskite modules (PeroCycle)
In terms of circular economy, it is necessary to research the recyclability of a new material right from the initial stage. This also applies to photovoltaic modules made of perovskite, an alternative to classic silicon modules. The ZSW is working with two industry partners to investigate how thin-film solar modules can be reused at the end of their service life. In four steps, the partners in the new “PeroCycle” project aim to develop an industrial recycling process for perovskite solar modules. Perovskite is an attractive material for the photovoltaic industry: as a tandem module with silicon, it significantly increases efficiency, is inexpensive to manufacture, and can be scaled up.
In order to achieve Germany's ambitious expansion targets in the field of renewable energies, it is necessary to act in accordance with the principle of circular economy. This means using finite resources sensibly and utilizing them for a long time. Once a PV module has reached the end of its service life, high recyclability and reuse are more important than ever. The ZSW, Solaveni GmbH from Bönen, and Solar Materials GmbH from Magdeburg are committed to this goal in the “PeroCycle” project. Solaveni contributes expertise in the chemical processing of perovskite materials, while Solar Materials specializes in the purely physical separation of composite materials without the use of chemicals. At ZSW, researchers can draw on over 30 years of experience with thin-film solar modules and over ten years of materials research on perovskite solar cells and modules. The German Federal Environmental Foundation (DBU) is funding the joint project.
Making perovskite modules recyclable
The research team's goal is to develop an industrial recycling process to enable optimal recycling of the modules at the end of their service life. To this end, the ZSW is first producing and encapsulating perovskite mini-modules.
In a second step, the encapsulated perovskite modules are separated at the industrial partner Solar Materials using thermomechanical processes. This involves testing whether the glass-polymer composite, and thus the glass as a whole, can be effectively separated from the perovskite absorber material. In contrast to conventional shredding, this process does not involve mixing with other materials. The glass can therefore be reprocessed into container glass. The perovskite absorber material is collected separately.
After the materials have been separated, step three follows: the development and optimization of a perovskite recycling process at Solaveni. The recycling process uses proprietary, non-flammable, cost-effective, and environmentally friendly solvent systems that eliminate the need for toxic solvents. Extreme conditions, such as high temperatures, are not used. The new approach reduces energy consumption and waste, thereby minimizing costs and environmental impact. The future recycling process will include chemical and physical processing methods. The goal is to recover at least 90 percent of the perovskite material with a purity of 99 percent.
In the fourth and final step, a new perovskite module will be manufactured at ZSW from the recovered materials. The recycled perovskite absorber material and the recycled glass coated with transparent contacts are used for this purpose. The researchers in the materials laboratory aim to achieve at least 90 percent of the efficiency of the freshly manufactured reference samples from the recycled materials.
A report on the current status of PV recycling in Germany can be found here: iea-pvps.org/key-topics/status-of-pv-module-take-back-and-recycling-in-germany/
The ZSW presented the latest developments in PV recycling at the PV Recycling Workshop on October 14 and 15, 2024, in Stuttgart. In addition to scientific presentations and a tour of the ZSW laboratory, participants had the opportunity to talk to stakeholders from industry and research. The next PV Recycling Workshop is expected to take place in November 2025.
