Future Return Flows of Cadmium-Telluride from Photovoltaic Waste——The Use of Dynamic Substance Flow Analysis to Predict Potential Recycling Flows Resulting from the Production and End-of-Life Waste of Photovoltaics

摘要

According to the European Photovoltaic Industry Association, photovoltaic energy has the potential to contribute up to 12.6 % to the global electricity supply by 2040. Part of the electricity produced will come from thin film technologies. Amongst other thin film technologies available on the market today, lowcost cadmium-telluride photovoltaics (CdTe-PV) is the market leader with a 5% share of the worldwide market. However, various studies show that the availability of tellurium can limit the further growth of this technology. Moreover, a possible legal ban of cadmium in photovoltaic modules threatens this technology. Efficient material and equipment use as well as the recovery of CdTe from production waste and end-of-life photovoltaic modules can minimize primary Te demand and prevent the release of toxic Cd emissions into the environment. This paper presents possible scenarios of Cd and Te recycling flows from PV waste, projected to the year 2040. Based on a market scenario portraying future material demand, amounts of recovered materials and material captured in installed modules are estimated. The results of this analysis show that in only 20 to 25 years significant amounts of end-of-life waste will reach the recycling market. Until this phase is reached, production scrap will dominate the waste flows. Due to the long lifetime of the products and the fast growing industry, high amounts of materials are estimated to accumulate in installed modules, thus creating a future urban mine. Tapping this resource by recycling ensures future material supply and avoids environmental burdens caused by the loss of Cd at the end of the modules productive life.