Methods for recycling photovoltaic modules and their impact on environment and raw material extraction

Abstract

This work deals with methods of recycling of photovoltaic modules and evaluates contribution of recycling to the environment and reduction of raw materials extraction. The article describes the materials needed to manufacture photovoltaic modules and energy intensity of production processes. Three methods of recycling were used - thermal, chemical and mechanical. The experiments have shown that the recycling of PV modules by thermal method is more advantageous than using a chemical method. The length of the process is significantly shorter and there are lower financial costs. The disadvantage of thermal treatment is the formation of emission gases during evaporation of the EVA copolymer and also a risk of waffer damage. In mechanical recycling process it is very important to know which technologies and devices are suitable to creation of crushed material. If the PV modules are bigger than 1 x 1 m, it was necessary to divide them into two parts because the chain crusher must be able to crush the pieces as effectively as possible. From the entire mechanical recycling process it can be seen that the silver-containing crushed material up to 0.07 % is not economically advantageous to process chemically. The silver content does not cover the cost of basic operations during recycling process. Based on obtained data was also theoretically calculated the amount of saved material due to PV module recycling until year 2025. Recycling could save up to 351 500 tons of glass, 51 500 tons of aluminum, 13 567 silicon and 425 tons of silver.This work deals with methods of recycling of photovoltaic modules and evaluates contribution of recycling to the environment and reduction of raw materials extraction. The article describes the materials needed to manufacture photovoltaic modules and energy intensity of production processes. Three methods of recycling were used - thermal, chemical and mechanical. The experiments have shown that the recycling of PV modules by thermal method is more advantageous than using a chemical method. The length of the process is significantly shorter and there are lower financial costs. The disadvantage of thermal treatment is the formation of emission gases during evaporation of the EVA copolymer and also a risk of waffer damage. In mechanical recycling process it is very important to know which technologies and devices are suitable to creation of crushed material. If the PV modules are bigger than 1 x 1 m, it was necessary to divide them into two parts because the chain crusher must be able to crush the pieces as effectively as possible. From the entire mechanical recycling process it can be seen that the silver-containing crushed material up to 0.07 % is not economically advantageous to process chemically. The silver content does not cover the cost of basic operations during recycling process. Based on obtained data was also theoretically calculated the amount of saved material due to PV module recycling until year 2025. Recycling could save up to 351 500 tons of glass, 51 500 tons of aluminum, 13 567 silicon and 425 tons of silver.