With increased demand for solar panels, there has been tremendous waste generation for the same. Companies are trying methods to economically and sustainably recycle the old panels. Venice-based startup 9-Tech used thermo-mechanic PV panel recycling process to recover materials.
The new thermomechanical method to recycle old PV panels developed by 9-Tech has achieved an 87% recovery rate for materials like copper, silicon, and silver with competitive energy consumption.
The purity of the recovered materials is high enough for reusing in other applications. The process includes manual disassembly for removing the junction box and aluminum frame. Then, panels are cut to remove the encapsulant in a continuous furnace to minimize energy loss. It uses a heat exchanger to reduce the amount of heat required for the treatment.
From 898 kg of PV panels, the following materials in said quantity were recovered.
- Glass – 581 kg
- Aluminum – 146 kg
- Junction boxes – 14 kg
- PV cells – 26 kg
- Copper tapes – 6 kg
- Silver – 0.45 kg
- Dust – 9 kg
Pietrogiovanni Cerchier, CEO 9-Tech said, “The process consists of a first manual disassembly phase, in which the aluminum frame and the junction box, made mainly of plastic and copper, are dismantled.”
“The panels are then cut into 33 cm strips to reduce their size and make them suitable for the next phase. The panel strips are subjected to a heat treatment to obtain complete combustion of the EVA encapsulant,” CEO further added.
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The Process of Thermo-mechanic PV Panel Recycling
Mechanical methods separate the copper strips, glass, and silicon cells. Rollers remove the copper wires and fine particles are eliminated by a vibrating sieve which also separates PV cells from the glass. A fume abatement system with a pocket filter is used in the process along with activated carbon. Finally, the silicon is recovered as small foil pieces under 20 cm2.
Presently, the company is improving the process for scalability and conducting lifecycle analysis. Moreover, they are looking for ways to use the recovered materials, especially silicon.
CEO Cerchier explained, “The recovered glass, aluminum and copper demonstrated that they meet the specifications for end-of-waste status, in accordance with point 1.2 of Annex I to Council Regulation (EU) No 1179/2012 of 10 December 2012.”
Source: Italian startup develops thermos-mechanic PV panel recycling