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Implementation of a CirculAr economy Based on Recycled, reused and recovered Indium, Silicon and Silver materials for photovoltaic and other applications

Periodic Reporting for period 2 - CABRISS (Implementation of a CirculAr economy Based on Recycled, reused and recovered Indium, Silicon and Silver materials for photovoltaic and other applications)

Reporting period: 2016-12-01 to 2018-05-31

CABRISS main vision is to develop a circular economy mainly for the photovoltaic, and synergy 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 and at least the same performances (i.e. cells efficiency yield) as by conventional processes and (v) involve EU citizens and industry.
For thin film waste, a new approach using a laser technology has succeeded by opening the thin-film photovoltaic modules without damage, resulting in higher value of the recycled glass.
For Si based PV modules, an innovative water-based technology has been developed (TRL6). Unlike conventional technologies (shredding), this process do not break glass and results on the collection of all materials in Si PV modules (backsheet, EVA and cells).
Several hydro- and ionometallurgical routes have been tested as innovative cost-effective methods for the extraction and the recovery of silver and silicon.

Three sources of silicon waste have been processed in the project: Si from End of Life PV panels, broken Si wafers and cells, and dry powders recovered from kerf loss.
Refining of silicon kerf has already led to metallurgical silicon grades of 3N. Metallurgical silicon has been transformed to solar-grade (5N-grade) by pyro- and hydro- metallurgical processes.
CABRISS was able to demonstrate an ingot with a size up to 156x156mm² from recycled Si powders using hot pressing process. 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 have been done to test recycling silicon at an industrial scale by producing a G5 silicon ingot.

To show the potential for cell manufactured from recycled materials, 2 modules made of 100% recycled materials have been produced, with a power output > 250W. Others 12 mini modules have been fabricated for testing purposes using different cells technologies.
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 <50µm 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 database 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 were continuously either established, if possible by direct measurements. Final reports on LCC and LCA have supported the development of business models for CABRISS. A market and competitive analysis has been produced to estimate available PV wastes and to analyse the economic potential of applications outside of the PV industry to develop new synergy and circular economy.
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 3N.
First efforts to reuse recycled materials in the PV value chain have been successfully demonstrated (ingots, solar cells, PV modules, wafer equivalents from recycled silicon powders, indium, and of recycled silver).

The proof of quality of recycled materials has been shown. Cz-Si/multi-Si wafers made from the recycled Si feedstock have been tested, silicon modules have been produced.
The project’s business model has been developed on 3 promising near to market key exploitable results. 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, silver and high purity glass (new delamination process).

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, silver and high purity glass. 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 world’s technological testbed and recycling leader when it comes to PV materials; and technologies developed within CABRISS—and put into industrial practice within Europe—could put European companies at an advantage when other regions’ PV waste volumes increase.