In view of the growing volume of used modules, photovoltaics recycling has become an intrinsic part of a sustainable PV industry. According to an IRENA study, Germany alone expects 1 million metric tons of electronic waste from PV modules by 2030. To make the solar industry fully sustainable, a circular economy must be set up. PV recycling has become economically feasible through a number of innovative recycling methods.
The number of PV modules that are taken out of service has been growing steadily since the first solar boom in 2007. With a typical life span of 20 to 30 years, we have to expect considerable volumes of used modules soon. By 2050, 78 million metric tons of PV waste are expected to arise. The industry is faced with the task of finding solutions for the sustainable disposal or recovery of the resources used.
Modern recycling processes can recover materials such as glass, aluminum, copper, silicon and silver. There are several reasons why recovering the raw materials and reintegrating them into the material cycle is key. Silver accounts for 10 percent of the production cost of a PV module, and around 30 percent of industrial demand for silver already comes from the solar industry. At the same time, recycling prevents the improper disposal of hazardous substances such as cadmium, arsenic and lead.
Can the recovered materials be reused in the production of new PV modules? At present, glass cannot be recycled at the level of purity required for it to be reused as PV glass. At least in Europe, reusing glass in other industries makes much more sense because transporting recycled materials to China, where most of the world’s PV production takes place, would make neither financial nor ecological sense.
A recycling process can be mechanical, chemical or thermal, or a combination thereof. The most frequent methods are mechanical, where modules are shredded and sorted. In addition, valuable materials are extracted using chemical solutions. Thermal methods use technologies such as laser, light pulses and high-pressure water jets to achieve a more sustainable recycling process.
The profitable operation of PV recycling companies while upholding high quality and maximizing the volume of recovered material remains a challenge, though. The improved coordination at collection points and more efficient transport systems could help save costs. In addition, processes must be optimized to prevent damage to functioning modules when installations are dismantled.