Minimizing contamination between different materials key to efficient PV module recycling

An international team of industry and researchers is developing technology and methods to improve the industry's ability to recycle decommissioned solar panels, avoiding waste and targeting recovery of silicon, silver, glass, and polymers with a purity sufficient for further use in the PV industry or beyond.

A European consortium, coordinated by Norway-based research firm Sintef, aims to achieve a recycling rate of 70 to 90% for key end-of-life (EoL) solar panel materials, including silicon, metals, glass, and polymer recovery at high purity levels. The multi-year Horizon Europe research project, dubbed Quasar, has received €7.1 million in funding.

“Today, mechanical recycling processes dominate the current market, and these processes are optimized for compliance with laws based on recycled weight rather than value and economics,” Martin Bellmann, Sintef Senior Business Developer and Quasar project coordinator, told PV magazine. “The success and profitability of recycling largely depends on the ability to minimize contamination between different materials, isolate hazardous substances, and recover high-purity fractions of valuable and energy-intensive materials.”

The group says it is taking a holistic, or end-to-end circular approach to move from today's limited recycling and recovery, which has typically focused on aluminum frames and glass.

One of the challenges to overcome is how to handle encapsulation polymers. Another challenge is the evolving design of new generations of solar panels, which differ in size, properties, and material composition, which makes it hard to create a one-size-fits-all solution, according to Bellmann.

Launched in September 2023 with a four-year duration, the project has already produced a detailed report quantifying key materials and identifying EoL sources in the European Union for sustainable waste management. It also launched a best practice guide for solar panel field inspection to promote sustainable solar panel handling from inspection to recycling.

The team will build two pilot lines, one using chemical treatment delamination, and the other based on water jet delamination, while the overall process is expected to be improved by applying digital technologies and processes. For example, digital product passports that enable tracking and managing of sensor-equipped solar panels across their lifecycle, capturing information on production, material composition, and condition.

Technology is also being developed to enable rapid, non-destructive testing methods to assess the condition of EoL panels in the field, and at waste treatment facilities to decide if they will be reused, repaired, or recycled.

The Quasar approach reportedly considers the supply chain, including concepts of reverse logistic technologies, machine learning, product lifecycle information management (PLIM) based on digital twin modelling, and best practices for sorting, as well as warehouse operations, testing, repair and reuse.

The research consortium includes PV module manufacturers, utility-scale PV system operators, collectors, recyclers, and end users of recycled secondary raw materials. In no particular order, the participants are Sintef, Elkem, Equinor Energy, Buhck Re.Energy (2ndLife Solar), LuxChemtech, Solitek, Scatec, Rosi, Soren, Dow Silicones Belgium, Dow Chemical Iberica, Institut Photovoltaïque d'Ile-de-France (IPVF), bifa Umweltinstitut GmbH, Hochschule Offenburg, Electric Power Research Institute Inc (EPRI), Renewables Norway, and Norner Research.