When comparing technologies for photovoltaic panel recycling, attention often tends to focus on the machine. How is the panel shredded? How is it delaminated? How many stages does the line include? How automated is it?
These are important questions. But they come before the decisive one: what does the process actually produce?
A photovoltaic panel recycling plant does not simply generate “recovered material”. It generates fractions that must have physical and quality characteristics compatible with a subsequent industrial process. And it is on these fractions that the result should be assessed.
1. Photovoltaic panel recycling: from module to outputs
A photovoltaic module is a composite material. Glass, aluminium, silicon cells, EVA, backsheet, copper and other materials are assembled to stay together for decades. The task of a recycling process is to travel the opposite path: liberate → classify → separate → refine.
The Stokkermill Solar lines for solar panel recycling produce distinct fractions of:
- aluminium;
- glass;
- silicon-containing concentrate;
- EVA and backsheet;
- copper.
But even this list tells only part of the story. Two fractions both labelled “glass”, for example, can have completely different particle sizes, contamination levels and industrial destinations. That is why, in photovoltaic panel recycling, quality must be defined in relation to the next outlet.
2. Aluminium: recovering the frame is not enough
Aluminium is one of the most economically attractive fractions of the panel. In the Stokkermill automatic platform, the entire process does not need to rely on prior manual removal of the frame. During treatment, the aluminium is liberated and then separated to produce a furnace-ready proler fraction, designed for the subsequent metallurgical process.
The difference matters. “Recovering aluminium” describes the material. “Producing a fraction compatible with a smelter” describes an industrial output.
3. Glass: one word, several fractions
Glass makes up the largest share by weight of a photovoltaic module. But the process does not necessarily produce a single uniform fraction: particle-size classification makes it possible to obtain different fractions. In documented Stokkermill configurations, the coarse fraction can be classified, for example, in the 2–8 mm range, while finer material can follow different recovery routes.
This is a fundamental point. The question is not only: “How much glass have we recovered?” But: “What glass have we produced?” Particle size, residual iron, polymer contamination and destination all change the value of the material.
4. The silicon-containing fraction
One of the most interesting fractions in photovoltaic panel recycling is the fine fraction resulting from the liberation of the cells. Simply calling it “silicon” would, however, be inaccurate: it is a fine silicon-containing concentrate, together with residual glass and metal traces, which may include silver.
This distinction matters because the mechanical process does not automatically produce silicon ready to return to the production of a new photovoltaic cell. The material requires further processing when the destination calls for a higher degree of refining. The task of the recycling line is therefore to produce a concentrated, controlled fraction that can correctly enter the next stage.
5. EVA and backsheet
The polymer fraction must also be liberated from the glass and other components. EVA and backsheet are recovered at the end of the process as a separate fraction.
Once again, the point is not just whether the material is present. What matters is how much residual glass it contains. What matters is the particle size. What matters is which industrial destination is available. The Stokkermill technical page also indicates possible destinations for these fractions, such as alternative fuels thanks to their calorific value, depending of course on the context and the destination supply chain.
6. Copper: little weight, high value
Copper accounts for a relatively small share of the panel’s total weight, but it has high economic value. It is found mainly in the conductors and electrical connections. That is why even small losses spread across the other fractions can become significant as the volume processed increases.
It is the same principle we have known for years in cable recycling: it is not enough to look at how clean the recovered copper is. You also need to check how much copper has not been recovered.
7. Recovery and purity are not the same thing
Here we come to one of the most important principles. A very pure material does not automatically mean that the whole process has worked well. Imagine a process that produces one kilogram of extremely pure copper: if a significant amount of copper remains dispersed in the plastic or in the fine fractions, the overall result is not as positive.
Conversely, pushing every separation towards the maximum theoretically possible purity can require additional machines, energy and wear, without the downstream market actually paying for that level of quality. The industrial result must therefore strike a balance between:
- recovery;
- purity;
- particle size;
- energy consumption;
- operating cost;
- material value;
- specification required by the buyer.
8. How much is recovered in photovoltaic panel recycling?
In documented Stokkermill Solar configurations, the recovered fractions as a whole can reach up to 99.8% of the weight of the input material. But this figure must also be read correctly: recovery by weight does not, on its own, tell you whether each fraction has reached the required quality.
That is precisely why the process includes different stages of:
- size reduction;
- delamination;
- screening;
- magnetic separation;
- non-ferrous separation;
- refining;
- particle-size classification;
- and, when required, more advanced sorting technologies.
Not to multiply machines. But to build the required output.
9. From recovery to destination
The final step is perhaps the one discussed least: where does the material go? An output only gains real value when there is a downstream industry capable of using it:
- aluminium to metallurgy;
- glass to supply chains compatible with that specific particle size and composition;
- silicon-containing concentrate to further recovery activities;
- copper to the metallurgical supply chain;
- polymers to destinations compatible with their characteristics.
That is why designing a photovoltaic panel recycling line starting only from the incoming panel is incomplete. Upstream and downstream must be designed at the same time: INPUT → PROCESS → OUTPUT → DESTINATION.
10. At ECOMONDO 2026 we will put outputs at the centre of the discussion
From 3 to 6 November 2026, ECOMONDO returns to the Rimini Exhibition Centre. For Stokkermill Solar, it will be an opportunity to shift the conversation from the machine alone to the result of the process.
Not just: “How do you recycle a panel?” But: “What materials do you obtain, with what characteristics, and where can they be used?” Because that is where a photovoltaic panel recycling process truly proves its value.
11. Frequently asked questions
Which materials are recovered from photovoltaic panel recycling?
Aluminium, glass in different particle-size classes, copper and other metals, an EVA/backsheet polymer fraction and a fine concentrate containing silicon, residual glass and metal traces.
Is the recovered silicon ready to produce new photovoltaic panels?
Not necessarily. The mechanical process produces a concentrated silicon-containing fraction that may require further refining treatments depending on the final destination.
Why is photovoltaic panel glass separated into several particle sizes?
Because particle size, composition and contamination affect the possible industrial use of the fraction.
What does “furnace-ready” aluminium mean?
It means producing a fraction prepared for the subsequent metallurgical process, reducing the need for further cleaning and preparation.
In photovoltaic panel recycling, is recovery or purity more important?
They must be assessed together. High purity with heavy material losses is not necessarily a good result; likewise, increasing purity beyond what the market requires can add cost and energy without creating value.
How much material can a Stokkermill Solar plant recover?
In configurations documented by Stokkermill, the recovered fractions can account for up to 99.8% of the weight of the incoming panel.
19/10/2026