As the solar industry grows, addressing the end-of-life management of photovoltaic (PV) modules is becoming increasingly urgent. According to European industry association PV Cycle, a 10 MW solar site can eventually generate around 700 tons of waste material. This highlights the need for efficient recycling protocols for solar panels to minimize waste and maximize the recovery of valuable materials. However, current recycling methods still face several obstacles, including low material purity and complex regulatory frameworks.
Current State of Solar Panel Recycling
Most of the easily recyclable components of PV modules, such as aluminum, steel frames, and copper wiring, are already being processed by established recycling markets. However, while these processes keep panels out of landfills, they often degrade the quality of recovered materials, making them unsuitable for high-value applications such as manufacturing new solar modules. For example, Longi, a leading solar manufacturer, has successfully integrated recycled aluminum into its frames but acknowledges that incorporating other recycled materials remains a significant challenge.
The need for specialized recycling methods that separate and treat PV module materials independently is crucial. In the European Union, solar panel waste is currently regulated under the Waste Electrical and Electronic Equipment (WEEE) directive. However, industry experts argue that a dedicated legislative framework for renewable energy equipment would ensure that solar panels reach appropriate recycling facilities.
Advanced Recycling Technologies: Moving Beyond Shredding
To overcome the limitations of traditional shredding methods, companies in Europe are developing advanced recycling techniques. One promising approach is pyrolysis, which involves heating solar panels in an oxygen-poor environment. This method is employed by French PV recycler ROSI, which opened its first facility in Grenoble in 2023 and is expanding to Spain. Pyrolysis effectively separates glass and silicon cells from the polymer encapsulant, achieving higher purity levels and more sustainable recycling outcomes.
The emphasis on glass recycling is particularly notable, as glass makes up the largest volume of materials in a solar panel. ROSI estimates that glass constitutes around 70% of the material processed at its facility. The company collaborates with European glass manufacturers to validate the quality of its recycled glass cullet, achieving transparency standards that meet or exceed industry requirements.
Challenges with Recycling Silicon and Other High-Value Materials
Silicon cells, which contain valuable silver, represent another critical target for recyclers. Traditional shredding often yields silicon at only 80% purity, which is insufficient for most high-value applications. Solar-grade silicon requires an extremely high purity of 99.9999% (6N), and even slight deviations can prevent its reuse in new solar cells. ROSI has developed a mild chemical process to separate and purify silicon and silver after pyrolysis, ensuring that these materials maintain their value.
However, the presence of antimony in most solar glass poses another challenge, as few European manufacturers are equipped to process antimony-containing glass for new solar panels. ROSI is advocating for the use of antimony-free glass in future solar installations to make recycling more feasible.
The Cost of Recycling: A Major Hurdle
Recycling PV modules is often cost-prohibitive, and the financial burden of keeping panels out of landfills is a significant challenge for the industry. ROSI and other recyclers currently charge for their recycling services, highlighting the need for clearer regulations and dedicated legislative support to drive down costs and encourage widespread recycling practices. As PV waste volumes increase, the development of efficient recycling technologies and business models will be crucial for maintaining a circular economy within the solar industry.