Solar Panel Recycling: A Second Life for Sustainable Power

Have you ever wondered what happens to solar panels once they can no longer generate photovoltaic power? While they produce electricity without emissions or waste for decades, they eventually reach the end of their lifespan and become waste themselves—the only waste they generate.

That’s where solar panel recycling comes in, the icing on the cake that strengthens the sustainability of renewable energy. More than 90% of a solar panel’s composition consists of highly reusable materials such as glass, aluminium, and plastic. In the energy transition, even what’s considered obsolete can find a new purpose. Here’s how.

What will you learn in this article?

• The current state of solar panel recycling
• The three stages of the recycling process
• The different recycling methods

The current state of solar panel recycling

Global solar photovoltaic (PV) capacity continues to rise. According to the International Energy Agency's (IEA) Solar PV Global Supply Chains study, an estimated 400,000 to 600,000 tonnes of solar panel waste will be generated by 2030, increasing to between 11 and 15 million tonnes by 2040. This makes it crucial for governments, industries, and stakeholders to implement circular economy strategies to manage these materials.

The current rate of solar panel recycling varies significantly by region. In the United States, for example, less than 10% of discarded solar panels are recycled. Meanwhile, the European Union—where strict regulations enforce recycling—boasts a figure closer to 95%, according to the same IEA report.

The three stages of the recycling process

Recycling solar panels plays a vital role in ensuring the sustainability of renewable energy. While these devices generate clean electricity for decades, they will eventually need to be processed. Without proper recycling, they could end up as waste, missing the opportunity to be reused.

The IEA’s Roadmap to Net Zero by 2050 indicates that, if solar panels were properly collected at the end of their useful life, recycled materials could supply more than 20% of the photovoltaic industry’s demand for aluminium, copper, glass, and silicon, while meeting nearly 70% of its silver demand between 2040 and 2050.

The process unfolds in three critical stages:

1. Collection and sorting

The first step is gathering defective or end-of-life solar panels, typically after 20 to 30 years of use. These panels may come from residential, commercial, or large-scale solar farms. Once collected, they are sorted by type and condition to determine the most effective recycling approach and maximise material recovery.

2. Dismantling

Next, the solar panels are disassembled to separate their main components. Large parts, such as aluminium frames, are removed first. Then, the glass layers and photovoltaic cells are carefully taken apart to prevent damage to reusable materials. Precision is essential in this process to maintain material quality for reuse..

3. Material separation

Once disassembled, the materials are processed separately. Glass, which makes up around 75% of a panel, is cleaned and crushed for use in new panels or other products. Aluminium is melted down and repurposed in various industries. Plastics can be recovered to manufacture new products. Photovoltaic cells undergo further treatment to extract valuable metals such as silicon, silver, and copper.

Three types of solar panel recycling

When recovering raw materials from solar panels, three main recycling methods are used: mechanical, chemical, and thermal.

1. Mechanical recycling

Mechanical recycling is currently the most common method. It involves shredding and physically separating the components of solar panels. The main steps include:

• Initial disassembly – External elements such as cables and aluminium frames are removed.
• Shredding – The panels are broken down into smaller fragments.
• Separation – Glass and aluminium are separated using techniques such as air currents or vibration. Recovered glass is often reused in new panels or products like fibreglass.

This method is simple and cost-effective, allowing large amounts of glass and aluminium to be recovered. However, it is less efficient in recovering materials such as silicon and rare metals compared to other methods.

2. Chemical recycling

Chemical recycling uses specialised solutions to dissolve certain components, facilitating the extraction of valuable materials such as silicon and precious metals from solar cells. The process involves:

• Initial separation: Metallic elements and glass are removed.
• Chemical treatment: Solar cells are subjected to chemical baths that dissolve polymers and metal layers.
• Purification: The recovered materials are refined for reuse in new solar panels.

This method allows for the recovery of high-purity materials, particularly silicon. However, the chemicals used require careful handling and disposal to minimise environmental impact.

3. Thermal recycling

Thermal recycling involves exposing solar panels to high temperatures to remove plastic materials and adhesives, making it easier to recover key components. The process consists of:

• Controlled heating: The panels are subjected to high temperatures, usually in ovens, to burn off the encapsulating polymers.
• Materials recovery: Extracted materials such as silicon, glass, and metals are collected for reuse.

While this method effectively removes unwanted waste and facilitates raw material recovery, it requires significant energy and must be carefully controlled to prevent harmful emissions.

Solar panel recycling not only closes the life cycle of these devices but also paves the way for a more sustainable future rooted in circularity. Transforming what is no longer useful into new resources demonstrates how even discarded materials can have a positive impact on the planet.