Solar energy is one of the strongest symbols of the energy transition. Over the last two decades, photovoltaic installations have expanded rapidly across Europe and globally. This growth is essential for decarbonization, but it also creates a new industrial responsibility: solar modules must not become tomorrow’s waste problem. They need to become a source of secondary raw materials.
Today, most photovoltaic recycling systems are still focused on the more accessible parts of a module: aluminium frames, glass, cables and junction boxes. These fractions are relatively easy to separate and already have established recycling routes. The more difficult part begins after this first recycling step. Inside the laminate, valuable materials are strongly bonded together: solar cells, polymers, metallization layers and conductive components. These complex residue streams are often difficult to process economically and are therefore still underutilized.
This is where the next step in PV recycling must happen.
At Circular Silicon, we focus on recovering value from the materials that conventional recycling often leaves behind. Our work is centered on silicon-, silver- and copper-bearing residues from PV recycling, especially laminates, flakes, granulates and fine fractions. These streams are technically challenging, but they also contain significant untapped value. In our view, the future of PV recycling will not be defined only by how much glass and aluminium can be recovered. It will be defined by whether the industry can also recover the functional materials that made the solar module valuable in the first place.
Silicon deserves particular attention. It is the core functional material in crystalline solar cells and one of the most energy-intensive parts of the solar value chain. Producing high-quality silicon for photovoltaic applications requires complex industrial processing, high temperatures and significant energy input. The International Energy Agency describes solar PV manufacturing as highly electricity-intensive, with much of the energy demand concentrated in polysilicon, ingot and wafer production.
At the same time, Europe has only limited control over large parts of the global PV manufacturing chain. The European Commission notes that while the EU has strengths in certain parts of the PV value chain, additional capacity is still needed in areas such as wafers, cells and solar glass production. This makes recycling more than an environmental issue. It is also a question of industrial resilience.
If Europe wants to strengthen its position in solar technology, it cannot only look at new manufacturing capacity. It also has to look at the material already installed across the continent. Millions of modules will reach end-of-life in the coming years. Each of them contains materials that required energy, industrial infrastructure and global supply chains to produce. Losing these materials after one use would be a missed opportunity.
The European regulatory environment is already moving in this direction. The Critical Raw Materials Act sets a clear strategic framework for improving Europe’s access to critical and strategic raw materials, including stronger domestic recycling capacity. The European Commission highlights recycling as one of the key pillars for reducing dependency on concentrated third-country supply chains.
For the solar industry, this creates a clear signal: recycling quality will matter more. It will no longer be enough to demonstrate that modules are collected and treated. The question will increasingly be what materials are actually recovered, in which quality, and whether they can be returned to industrial value chains.
This is especially relevant for silicon. Unlike aluminium or copper, silicon from PV modules does not yet have a mature, large-scale circular pathway in Europe. The material is present, but it is embedded in a complex matrix of glass residues, polymers, metals and fine particles. Recovering it requires more than simple dismantling. It requires selective processing, material characterization and downstream upgrading routes.
Our approach at Circular Silicon is to treat these residue streams not as waste, but as secondary raw material sources. The first step is understanding the input: What type of PV fraction is it? How much glass, polymer, cell material and metal does it contain? What is the particle size? Which impurities are present? Only after this material understanding can a realistic recycling pathway be defined.
The second step is aggregation. Many recyclers generate relevant residues, but individual volumes are often too small to justify dedicated high-value recovery. By bringing these material streams together, specialized processing becomes more feasible. This aggregation model is essential for turning a technical possibility into an industrial business case.
The third step is developing reliable output streams. A recycled material only creates circular value if it can be used by downstream industry. This means that quality, consistency and documentation are crucial. For silicon-rich products, this includes purity, particle size, contamination profile and suitability for further upgrading. The goal is not only to separate material, but to create a product that can realistically enter the next processing step.
This is also where silver and copper remain relevant. They are valuable metals and important contributors to the economics of PV recycling. However, the long-term strategic opportunity lies in building a more complete recovery chain where metals and silicon are considered together, rather than treating silicon-rich residues as a low-value side stream.
Europe has a unique chance in this field. The continent was among the early adopters of solar energy and will therefore also be among the first regions facing large end-of-life PV volumes. This creates pressure, but also an opportunity to build the next generation of recycling infrastructure before the waste volumes peak. If Europe develops scalable solutions now, it can become a leader not only in deploying renewable energy, but also in managing renewable energy materials responsibly.
The future of solar must be circular. That means recovering more than the easy fractions. It means addressing the complex materials, the mixed residues and the functional components that are currently not fully used. Silicon recovery is one of the missing links in this system.
For Circular Silicon, the mission is clear: to help close this gap by transforming difficult PV recycling residues into defined secondary raw materials. By doing so, we aim to reduce material losses, support European raw material resilience and contribute to a solar industry that is not only clean during operation, but also responsible at end-of-life.
