| Work Detail |
The French research institute CEA-INES has presented in a scientific article the technical details of its recyclable heterojunction module with a power of 566 W and a carbon footprint of only 313 kgCO2eq/kW.
Researchers from the National Institute of Solar Energy (INES) of France - a division of the Commission for Alternative Energies and Atomic Energy (CEA) - have published an article in which they describe the technical characteristics of the industrial-scale prototype of a heterojunction module of silicon (SHJ) that was announced early last year.
“The article explains all the technical details and complementary results,” corresponding author Timea Béjat told pv magazine , noting that the team used an internal ECO PV tool to perform life cycle analysis (LCA) studies with in order to optimize the design of photovoltaic modules to reduce their environmental impact. Béjat also noted that a key finding of the research was that very low-carbon designs could be achieved with currently available technologies.
The scientists built the panel using a CEA-INES pilot line. They used 130 µm Czochralski M2 wafers, vapor deposition, and transparent conductive oxide on both sides in a 6-bar design cured at 200 C for 15 minutes. The cells bifaciality factor was on the order of 92%, the team noted.
“For a standard photovoltaic module, we identified the main steps to improve to reduce its environmental footprint,” the research team noted. “This guided us to address the components with the greatest impact on the carbon footprint, namely the wafer, the glass front sheet and the aluminum frame.”
At the cell level, the academics reduced the thickness of the wafers, which they claim were purchased through “the European value chain.” Metallization and cell interconnection were optimized to reduce silver consumption. In the module, the thickness of the glass was reduced and the conventional aluminum structure was replaced with a wooden one with a glass and backsheet configuration.
Additionally, we applied a “design for recyclability” approach in the choice of encapsulant and backsheet,” the team says. “The combination of these innovations led us to the realization of a 566 W recyclable module using a mosaic interconnection, cells with an average efficiency of 22.57% with a carbon footprint of 313 kgCO2eq/kWp.”
The carbon footprint of the prototype, at 313 kgCO2 eq/kW, is better than that of current conventional modules, which, according to the team, ranges between 700 kgCO2eq/kWp and 800 kgCO2eq/kWp.
Supposedly, it is also lower than the products of the “pioneer manufacturers” that have achieved modules below 450 kgCO2eq/kWp, such as the Korean Qcells, the Belgian Bisol, the Singaporean REC and the Chinese manufacturers JinkoSolar, Trina Solar and Huasun, according to the research team in a non-exhaustive list.
As for the bill of materials, the group claims to have adopted a “design for recycle” approach, which means choosing a thermoplastic encapsulant, a fluorine-free backsheet, and a thin front glass. Additionally, using a wooden frame instead of aluminum reduced the carbon footprint by more than 50-60 kgCO2eq/kWp, the researchers noted, but they also stressed that qualification of this type of material has not yet been completed. of frame.
The team concluded that, by optimizing technical parameters and selecting environmentally friendly materials, it was “able to develop an eco-designed photovoltaic module with a very low carbon footprint,” and demonstrated the importance of finding a compromise between optimizing environmental impact and module performance and durability.
According to the team, in the future they will try to improve performance and reduce the consumption of materials, such as silver, both at the cell and module level, as well as integrate the content of recycled material in all phases of the value chain. The team also plans to investigate alternative backsheet materials without aluminum or fluoromaterials and work to establish the reliability of the alternative shell material.
The project “ Design for the environment: SHJ module with ultra-low carbon footprint ” was recently published in Progress in Photovoltaics . |
