PROJECT DESCRIPTION
BACKGROUND
The stock of photovoltaic (PV) panels has been rising sharply in recent years and is currently estimated at some three million tonnes in the EU. However, sustainable solutions for the recovery of PV waste are still not well developed, and if not disposed of correctly, this waste can cause both environmental and human health problems. It is forecast, for example, that from 2015 onwards, 30 000 t/year will be disposed in Europe, and over the next 20 years this amount could reach 500 000 t/year, including: c. 390 000 t/year of glass; 55 000 t/year of aluminum; 35 000 t/year of plastics; and 11 500 t/year of crystalline silicon cells.
Since 2012, PV has been included in the EU WEEE Directive, which requires manufacturers and importers to facilitate and finance the take-back and recycling of their discarded end-of-life products. Current technologies recycle glass in low-value industries, such as glass fibre and insulation. They do not allow for recovery of metals, especially crystalline silicon, which is used in more than 90% of PV cells worldwide. Silicon production implies energy costs that are equivalent to three years of PV energy production, which represents a serious drawback in terms of its environmental performance from a life-cycle approach.
OBJECTIVES
The LIFE FRELP project aimed to test and develop innovative technologies for 100% recycling of end-of-life PV panels in an economically viable way. Two main environmental solutions were proposed:
- The recovery of high quality extra clear glass, to be used in the hollow and flat glass industry, thus implying very significant energy and CO2 emission savings in the glass melting process;
- The recovery of (metallic) silicon, to be used as ferrosilicon in iron silicon alloys or, if pure enough, transformed into amorphous silicon for the production of thin films, thus greatly reducing energy consumption and CO2 emissions associated with the production of primary silicon.
RESULTS
The LIFE FRELP project did not achieve any of the foreseen objectives. However, partial results have been achieved with the design of the prototype for detaching the EVA polymer back sheet from glass and of the robotic system for the detachment and recovery of the aluminium frame and connectors from the PV panels.
The project constructed a pre-prototype, not foreseen in the original concept, to test the technology for the detachment of the EVA film from the glass. This mini plant did not work very well, but was useful to implement the design of part of the project prototype.
Two out of three technologies foreseen to be implemented, i.e. the thermal cracking of the plastic material obtained from the dismantling of PV panels and the leaching treatment process with sulphuric acid, proved not to be viable when tested at the laboratory scale. These innovations could not be applied in the construction of the foreseen prototype, so that the project demonstration value is null.
