Economic PV waste recycling solutions - results from R&D and practice

Total quantities of end-of-life photovoltaic panels in 2050 are anticipated to amount to 9.57 million tones [I]. We are not there yet, but discussions on recycling have already started. So we are preparing for higher waste volumes expected to arrive in the next years. But even today we have to solve some environmental problems: loss of conventional resources (e.g. glass) or loss of rare metals with strategic importance [2]. Cadmium, selenium, tellurium, gallium, molybdenum and indium are some of the major elements used in these photovoltaic cells. We know about the future limits in the availability of these elements. So recycling is required as the most advisable end-of-life strategy and to save the raw materials from production wastes now. On the other hand statutory prescriptions, as e. g. the German "Kreislaufwirtschaftsgesetz" (law encouraging closed-loop economy) are asking for a maximum quota of recycling - and a minimum use of resources (e. g. energy, raw materials). All of the known approaches to the recycle of photovoltaic semiconductor materials seem economically and environmentally inefficient [3], [4]. We report a method for extracting and reclaiming metals from scrap of CIS, CIGS or CdTe systems and associated photovoltaic manufacturing waste (sandblasting dust). We found one universal chemical process for reclaiming the metals from CIS, CIGS or CdTe photovoltaic waste. We also discuss the application of our method to new PV systems, such as substrates other than glass (aluminum or stainless steel foil sheets), and other semiconductors such as GaAs.