Project partner: SOLYCO TECC GmbH
As we work toward achieving climate neutrality by 2045, photovoltaics (PV) is a key pillar in reducing CO2 emissions. However, we must also aim to minimize the environmental impact of PV module production - especially given the high global installation rates expected in the coming years.
To balance expansion goals with the environmental impacts associated with raw materials, the amount of critical raw materials used per PV module must be reduced. Due to high costs, the PV industry is making a concerted effort to address the raw material challenges associated with silver-based cell metallization and the interconnection of cells into strings. In addition, cell connectors are typically soldered at approximately 200 °C using a tin-lead-silver solder. Lower soldering temperatures can only be achieved with bismuth- or indium-based solder. The ecological and economic criticality of the materials silver (Ag), lead (Pb), bismuth (Bi), and indium (In) requires new approaches.
The problem of critical raw materials and low-temperature interconnection can be solved with TECC-Connect for cell interconnection. TECC-Connect (Thermoplastic and Electrically Conductive Coating) is the world’s only commercially viable cell interconnection technology for PV modules that is completely free of Ag, Pb, In, and Bi. Previous work on TECC-Connect has only marginally addressed the downstream processing steps in module production. Key steps here include removing insulation from the TECC strings at the string ends and the subsequent cross-connection using cross-connectors. Both processes—stripping and cross-connecting without critical raw materials—are technologically challenging and have so far only been tentatively attempted in the laboratory.
Therefore, the goal of PV-Free is to identify alternative processes for sustainable cell metallization and the stripping and cross-connecting of TECC strings for module production. The various options for this are being experimentally tested by the partners. This project does not yet aim to optimize feasible alternatives. Rather, it involves an initial screening of possible alternatives for the processes leading to a sustainable product design.
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