Wanted: Recycling strategies for solar modules

25.03.2024


Source: Energy & Management Powernews

A study by the Helmholtz Institute Erlangen-Nuremberg for Renewable Energies describes how photovoltaic modules should be dealt with at the end of their production cycle.

PV is booming worldwide. And every year, countless modules are added to rooftops and open spaces. By 2050, several million tons of waste from old modules are expected in Europe alone. "Circular recycling strategies are necessary in order to avoid waste streams in the future that are in the order of magnitude of today's global electronic waste," concludes a study by researchers from the Helmholtz Institute Erlangen-Nuremberg for Renewable Energies (HI ERN).

However, current solar modules are only suitable for recycling to a limited extent. This is mainly due to their integrated structure, which makes it difficult to separate the materials easily. "Even though recycling is mandatory in the European Union, PV modules are therefore difficult to reuse in a circular way," it says.

Although there is currently no material shortage for PV modules, the enormous expansion of photovoltaics requires efficient material management. The HI ERN study points the way to a "more sustainable and economically viable future for the PV industry". Future solar modules would have to be designed for an "eternal cycle".

This means that the materials would have to be easier and more efficient to separate from each other, while at the same time improved documentation and characterization of the materials used would be required. Ultimately, the success of the recycling process will depend heavily on its economic feasibility.

PV industry consumes 12.7 percent of silver production

The study cites the processing of glass as an example of the challenge. 75 percent of the module mass consists of solar glass. The glass recovered during recycling is currently only of inferior quality and cannot be used to manufacture new modules. Circular recycling would not only prevent this glass from ending up as waste, but would also strengthen the economic position of the solar industry, according to the study. Similarly, the use of certain polymers competes with other industries such as the footwear industry, which can cause bottlenecks in production. Circular recycling could avoid bottlenecks and recover valuable materials.

Another example is the use of silver in PV systems, with the solar industry already consuming 12.7 percent of annual silver production in 2020. "Future modules will and must manage without silver," says the study. But until then, thousands of tons of silver will be used in modules. Circular recycling makes it possible to "raise this treasure and make it available."

The study "Cradle-to-cradle recycling in terawatt photovoltaics: A vision of perpetual utility" is available on the Internet and can also be downloaded as a PDF.

Author: Stefan Sagmeister