Recycling of solar panels

How does solar panel recycling work?

Photovoltaic energy Energy transition

Solar photovoltaic energy is the third most important renewable energy source in terms of installed capacity globally, with growth of 22% in 2022, according to data from the International Renewable Energy Agency (IRENA). The same agency estimates that there could be 78 million tonnes of solar panels worldwide by 2050. For this reason, and to ensure that the environmental impact of this renewable energy is as low as possible, photovoltaic panels, which have a useful life of around 30 years, are recycled, although their efficiency is reduced by between 6 and 8% after 25 years.

These panels are mainly composed of silicon, glass, aluminium and semiconductor materials that can be reused and recovered through recycling. In fact, this recycling has been mandatory in the European Union since 2012, which stipulates that solar panel manufacturers must collect and recycle solar panels at the end of their life cycle. This is not the case in all countries; in the United States, for example, this obligation depends on the states.

What is the recycling process of solar panels like?

The solar panel recycling process is not always the same as it can vary depending on the specific technology used to manufacture the panel as well as the available recycling facilities and innovation. However, in general terms, the process usually follows these steps:

• Reception and sorting: The solar panels arrive at the recycling centre, where their condition is checked and they are sorted according to the type of technology and material they contain.
• Disassembly: This is one of the most important parts of the process. The main parts are disassembled, such as the glass, the PV cells and the aluminium frame which, for example, is 100 % recyclable. This can be done manually or with specialised machinery.
• Material separation: Part of this process includes thermal recycling whereby, once the aluminium and glass have been removed, the panel undergoes thermal processing at over 500°C to burn off any remaining plastics that may still be attached. The next step is a series of chemical processes called delamination to remove the polymer layer and separate the metal contacts. Finally, the wafers are etched from silicon, a material that is more than 80 % reusable, before being fused into reusable plates.
• Recycling: Recovered materials undergo specific processes to purify them and prepare them for final reuse or recycling. For example, silicon can be refined for use in the manufacture of new solar panels, as can glass or aluminium. 

Benefits of solar panel recycling

There is no doubt that recycling solar panels brings a number of benefits to the environment, making solar photovoltaic energy an increasingly cleaner energy with less environmental impact. It is important that solar panels are recycled properly, not only to reuse the valuable materials they are made of, but also to minimise the contamination of potentially harmful components such as lead and cadmium. By recycling them properly, the recycling centre will be able to dispose of these materials safely.

Furthermore, the recycling of solar panels is a stimulus for the circular economy, creating new business and employment opportunities in the recycling sector, while reducing dependence on primary resources. And if these materials are reused, it also reduces pressure on the environment and promotes sustainability.

There is no doubt that solar panel recycling is an important driver of the energy transition, contributing to the sustainability and efficiency of the solar energy sector. This is essential in the transition towards cleaner and renewable energy sources, which in turn helps to reduce greenhouse gas emissions and mitigate climate change.