The shift away from fossil fuels has begun and means a much more comprehensive electrification of society – for example, for electric mobility, but also for heating. However, this requires a massive expansion of renewable energy generation. Electricity generation using photovoltaics (PV) is one of the most cost-effective forms of renewable energy generation and will therefore undoubtedly become one of humanity's main energy sources.

 

However, current PV technology contains several critical materials such as silver, lead, and bismuth. It is simply not possible to expand the PV industry on a large scale without developing innovations that replace or eliminate these critical substances:

 

• Lead (Pb) is toxic and already banned in the electronics industry under the RoHS directive. However, the solar industry has been an exception, as it has so far been virtually impossible to completely remove lead from PV modules.
   

• Bismuth (Bi) is a byproduct of lead mining. Furthermore, solder joints containing bismuth are suspected of causing long-term product failure, which is why bismuth has been completely banned in the automotive industry. Replacing lead with bismuth is therefore not a solution.
   

• Silver (Ag) is a rare and expensive element. Although the silver content in a PV module is only about 5–10 grams, it accounts for more than 10% of the material costs. The solar industry already consumes 14% of global silver production—and silver mining is an environmentally harmful process. Eliminating silver is therefore a key goal of the global PV industry.

 

Making photovoltaics more sustainable is one of the central drivers of research and development work at SOLYCO. For years, we have been working on removing critical substances from PV modules. In 2018, we invented a new technology that is now ready for industrial application: TECC-Connect®.

 

TECC stands for "Thermoplastic and Electrically Conductive Coating" – thermoplastic materials with an electrically conductive coating. The technical innovation lies in a special coating on metal wires used to connect the solar cells in the module.

 

TECC technology eliminates soldering in the production of PV modules and enables electrical and mechanical connections to virtually any surface. This technical innovation—replacing the wire coating of solder with a functional plastic—enables a major advance: TECC is the only cell connection technology that makes solar modules completely free of silver, lead, and bismuth. TECC thus lays the foundation for the next leap in PV technology—in terms of sustainability and cost.

 

Furthermore, TECC wire operates at low process temperatures, making the technology suitable for next-generation solar cells, such as those using perovskite tandem technology. All required industry standards have already been successfully passed. The technology is fully RoHS compliant. TECC is also patent-protected.

 

The TECC-Connect® PV modules will be presented to the public for the first time at INTERSOLAR 2025 in Munich. We are currently working with several partners on the implementation of industrial mass production of the first generation of TECC-connect® modules, which will be available from 2026.