Life Cycle Analysis of Solar Module Recycling Process

Abstract

Since June 2003 Deutsche Solar AG is operating a recycling plant for modules with crystalline cells. The aim of the process is to recover the silicon wafers so that they can be reprocessed and integrated in modules again. The aims of the Life Cycle Analysis of the mentioned process are (i) the verification if the process is beneficial regarding environmental aspects, (ii) the comparison to other end-of-life scenarios, (iii) the ability to include the end-of-life phase of modules in future LCA of photovoltaic modules. The results show that the recycling process makes good ecological sense, because the environmental burden during the production phase of reusable components is higher than the burden due to the recycling process. Moreover the Energy Pay Back Time of modules with recycled cells was determined.

The development of a resource-efficient photovoltaic system

“…This leads to environmental benefits (instead of burdens) in most impact categories (Obersteiner et al, 2011). Other studies have also reported minor impacts from the EoL phase, with the major contributor being the module production, followed by the production of the various BoS components and the mounting system (Frankl et al, 2005;Jungbluth et al, 2008;Mü ller et al, 2006;Obersteiner et al, 2011;Saft, 2008;Sander et al, 2007).…”

Recent Advances in TASC (Thermal Activation of Semi-Conductors) Technology for Environmental Issues Focused on the Disassembly and Recycling of Solar Panels and Laminated Glass —A New Technology Characterized by Radical Propagation in Giant Molecules—

“…At present, pyrolysis, which burns wastes at about 500°C in atmospheric pressure, or oxygen-depleted atmospheres is the most common method to separate composite material into its original constituents. 24,25) Although many people still view pyrolysis as a means of recycling composite waste and many trials have been conducted, pyrolysis inevitably accompanies by-product ash such as carbonaceous deposits arising from imperfect combustion of polymers. In addition, unseparable parts often remain that are firmly fixed by polymer binders.…”

“…The effect has been interpreted as arising from the formation of a vast number of thermally generated defect electrons ("hole") in the valence band of semiconductors. 24) This triggers the decomposition of giant molecules such as polymers as shown schematically in Fig. 1.…”

“…Then, the radicals propagate throughout the polymer to make the whole polymer unstable, resulting in the fragmentation of the giant molecule into small pieces such as ethylene and propane, just like a domino phenomenon (step 2). 24) Then, the fragmented molecules react with oxygen in air to give rise to H 2 O and CO 2 (i.e. complete combustion: step 3).…”

Current Trends in Recycling of Photovoltaic Solar Cells and Modules Waste / Recykling Zużytych Ogniw I Modułów Fotowoltaicznych - Stan Obecny

“…Although the energy consumption during the recycling process is essential, the use of recycled wafers for wafer production instead of new ones can halve the Energy Payback Time (EPBT) of a module. Due to the reuse of recovered wafers and the recycling of glass and metals the recycling process of Deutsche Solar AG leads to a decrease of environmental burden by avoidance of the production of new wafers and material like glass [16].…”