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Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - CABRISS (Implementation of a CirculAr economy Based on Recycled, reused and recovered Indium, Silicon and Silver materials for photovoltaic and other applications)

Teaser

Summary

CABRISS main vision is to develop a circular economy mainly for the photovoltaic, but also for electronic and glass industries. It consists of the implementation of: (i) recycling technologies to recover indium (In), silver (Ag) and silicon (Si) for sustainable PV technology and other applications. The originality of the project relates to its novel cross-sectorial approach associating Powder Metallurgy (fabrication of Si powder-based low cost substrate), PV industry (innovative PV Cells) and the recycling industry (hydrometallurgy and pyrometallurgy).

Five research institutes and 11 companies from 9 EU countries work together to implement a pioneering approach towards a PV circular economy demonstrating the re-usability and recyclability of key PV materials for PV and other applications like electronics, metallurgy and glass industries.

CABRISS five main objectives are to (i) develop industrial symbiosis by providing raw materials as feedstock for other industries, (ii) collect up to 90% of the PV waste throughout Europe (as compared to the 40% rate in 2013), (iii) retrieve up to 90% of the high value raw materials from PV cells & panels (silicon, indium & silver), (iv) manufacture PV cells and panels from recycled raw materials achieving lower cost (25% less) and at least the same performances (i.e. cells efficiency yield) as by conventional processes and (v) involve EU citizens and industry.

Work performed

Two sources of silicon waste have been processed: broken silicon cells still with the anti-reflection coating, and dry powders recovered from kerf loss. A novel, economically and ecologically effective method was developed for silver recovery. In addition, several hydro- and ionometallurgical routes have been tested as innovative cost-effective methods for the extraction of silver and silicon from different sources of PV waste.
For thin film waste, a new approach using optical nanotechnology has succeeded by opening the thin-film photovoltaic modules without damage, resulting in higher value of the recycled glass. After that, metals were extracted using novel methodologies.
Refining of silicon kerf has already led to metallurgical silicon grades of > 99.5%. Metallurgical silicon has been transformed to solar-grade (5N-grade) by pyro- and hydro-metallurgical processes.
CABRISS was able to demonstrate an ingots with a size up to 156 mm-x-156 mm from recycled silicon powders using hot pressing. Several ingots have also been produced from recycled silicon by conventional crystallization approaches. In addition, silicon wafer equivalents have been directly processed by the thermal spraying of silicon powders. Further work will be done to test recycling silicon at an industrial scale by producing a G6-size silicon ingot.
To show the potential for cell manufactured from recycled materials, simulation models have been built. Al-BSF solar cells were fabricated on both reference and recycled silicon multi-c wafers. Efficiencies above 17% have been achieved.
A conductive bonding solution for gluing epifoil cells onto conductive silicon carrier substrates was developed and demonstrated. A high-efficiency cell process for thin silicon epitaxial foils was developed, resulting in >17% efficiency on freestanding epitaxial foil cells < 50 Âµm thick using HJ technology.

Recycled silver was processed and used to produce conductive pastes/inks.Several indium -based products (sputtering targets, bonding material) were fabricated and used in thin film manufacturing.

A data-base has been built to manage the circulation of material samples and to allow comparison of specific characterization techniques.
Life Cycle Analysis and Life Cycle Costing (LCC) data are continuously either established, if possible by direct measurement. A first report on LCC, available in January 2017, will support the development of business models for CABRISS. A first market and competitive analysis has been produced to estimate available PV wastes and to analyse the economic potential of applications outside of the PV field.

Final results

Progress beyond the state of the art: dismantling, extraction, recovery, recycling and reuse of materials from PV products
Several novel methods for the separation of materials prior to recycling or reuse have been developed in CABRISS. Recovered silicon from broken wafers and cells has been purified to solar grade silicon from lower quality metallurgical grade silicon, and Si kerf has been refined to 2N.

First efforts to reuse recycled materials in the PV value chain have been successful (ingots,wafer equivalents from recycled silicon powders, indium, and of recycled silver).

Expected results
The proof of quality of recycled materials needs to be shown. Cz-Si/multi-Si wafers made from the recycled Si feedstock have to be tested, silicon modules will be produced and the design for a smart module architecture adapted for recycling will be delivered.
The projectâ€™s business model will be intensified. The waste recycling companies involved in the CABRISS project already believe that end of life photovoltaic crystalline modules can generate a positive commercial value. Analysis carried out within the CABRISS project highlights that a considerable amount of value resides in the solar materials not currently recycled as a matter of routine, namely in the silicon and silver.

Potential impacts
CABRISS aims to make measurable reductions in the level of PV waste generation and in resource use in the medium term by developing and optimizing better recycling processes for critical materials such as silicon, silver, and indium. The project will have a considerable societal impact by improving resource efficiency, and avoiding dangerous wastes. In addition, CABRISS aims at reducing the environmental impact of the recycling process itself, optimising recycling procedures according to results of the LCA.
By 2018, the WEEE directive 2012/19/EU requires the recovery of 85% of PV waste, with the recycling and reuse of 80%. The obligations for PV manufacturers and distributors brought about by the new legislation create a need for new technology developments that are addressed by CABRISS. The project helps to transform legal obligations into new business opportunities. Economically viable processes to recycle silicon wafer kerf would be beneficial to ingot and wafering companies as they would gain value from selling their silicon powder. The economic recycling of broken or out-of-specification cells and modules would provide additional revenue to these companies and could help to offset the declining profitability against Asian competitors. More generally, a circular economy in recycled PV materials would prevent European PV manufacturers from importing a significant part of their needs for raw materials and could help insulate them from future price volatility.

Recycling companies could enhance their profit through the recovery of valuable materials like silicon and silver. The companies involved in the consortium have a very high interest in applying the developed innovations in their field of business, thereby creating new jobs and even new fields of economic activity. Europe has the potential to be the worldâ€™s technological testbed and recycling leader when it comes to PV materials; and technologies developed within CABRISSâ€”and put into industrial practice within Europeâ€”could put European companies at an advantage when other regionsâ€™ PV waste volumes increase.