Solar panel recycling explained

In 2023, there were 229,618 solar panels installed across the UK  – but what happens when they’re no longer in use? In this guide, we explore how solar panel recycling works, and what you need to do to ensure recycling of your panels takes place.

By 2050, it’s predicted that the world’s global installed PV capacity will reach 4,500 gigawatts (GW), up from 222GW at the end of 2015, according to the International Renewable Energy Agency (IRENA). But these solar panels will not last forever – the first generation of solar panels, which were installed in the late 1990s and early 2000s, are expected to reach the end of life in the 2030s. And without recycling infrastructure in place, we could see landfills fill up pretty quickly with defunct panels.

Solar panels can be recycled as they’re made almost entirely from aluminium, silicon and glass – materials that are easily broken down and can be given a new lease of life. However, currently, only 10 per cent are being recycled with around 90 per cent ending up in landfill. 

As the UK – and the rest of the world – moves ever closer to renewable energy sources, it would be a sad fact if those materials were wasted and created yet more climate doom. The solar boom, while positive for the environment, could create an even bigger issue if solar panels were not recycled. It’s believed that retired solar panels are estimated to cover an area equivalent to 3,000 football pitches by 2030.  

Why are 90 per cent of solar panels ending up in landfill? 

Currently, the reason most solar panels are ending up in landfills is due to a lack of infrastructure. Until very recently, the need for solar panel recycling facilities was not necessary. The first generation of defunct solar panels is only just becoming a concern – by 2016 it’s estimated that 4 million tonnes of PV had been installed globally, all with a lifespan of 25 to 30 years. This means that more infrastructure is needed to facilitate the large number of solar panels that will reach the end of life in the 2030s. 

How much solar PV waste will there be in the future? 

According to an IRENA report, by 2030 PV panel waste will reach four to 14 per cent of total generation capacity by 2030 and increase to over 80 per cent (78 million tonnes) by 2050. Though the sheer size of waste sounds worrisome, its financial value could help fund new solar panels. 

The raw materials recovered in 2030 will be worth an outstanding $450 million. This could be used to produce up to 60 million new solar PV panels. By 2050, global PV waste is projected to reach 5 million tonnes annually. The materials recovered are estimated to total $15 billion – this could fund as many as 3 billion new panels.  

This is exactly why solar panel recycling needs to be made a priority worldwide. In an ideal world, solar panels would function forever, but to know that they can be recycled and manufactured into more solar panels is reassuring. 

In the US, it costs around $15 to $45 per PV panel to recycle and only $1 to $5 to discard a solar panel in a landfill. Cheaper processes for recycling processes are needed before these costs can be flipped, but it’s likely this cost will come down over time, just like the cost of solar panels did for a while. It wasn’t until the cost of solar panels decreased and solar grants and incentives, such as the Renewable Heat Incentive (RHI) and the Feed-in Tariff (FiT) schemes, were introduced that the solar boom really started. 

The best solar panels have an average lifespan of 25 to 30 years – this remains the same regardless of manufacturer or company. All solar panels relatively function the same – in a nutshell, they convert sunlight into usable renewable energy – even though they have different power outputs, efficiencies and warranties. But what are the reasons for their end of life? 

According to research conducted by the International Energy Agency (IEA) in 2014, the most common causes for defunct solar panels are: 

• Optical failure (20 per cent of cases)
• Power loss (19 per cent of cases)
• J-box and cable failure (19 per cent of cases)
• Glass breakage (10 per cent of cases)

Although solar panels won’t last forever, on average, homeowners can expect them to pay for themselves within seven years, leaving plenty of time to reap the full reward of installing solar panels. 

All solar panels have a rate of degradation that contributes to their end of life. A panel’s degradation refers to the speed at which the panel loses its efficiency and output over time. With the advancement in technology, most solar panels degrade on average between 0.5 per cent and 1 per cent per year.

The main reason solar panels have a long lifespan is their lack of moving parts – this means there is little need for maintenance to fix broken parts. However, if you do notice a sudden drop in power output, call a professional for a service and maintenance. 

There are two main types of solar panels – silicon-based solar panels (including monocrystalline and polycrystalline) and thin-film panels. They can both be recycled, but the process differs slightly. Silicon-based solar panels are more common as, thanks to their higher panel efficiency, they’re more widely chosen by homeowners. 

A high percentage of solar panel material can be repurposed. Both types of solar panels are made up of similar materials. The reason their recycling processes differ is down to material type, and the percentage of these materials.

Silicon-based solar panels are made up of:

• 1 per cent metal
• 5 per cent silicon
• 8 per cent aluminium
• 10 per cent plastic
• 76 per cent glass

Thin-film-based panels are made up of:

• 1 per cent metal
• 6 per cent aluminium
• 4 per cent plastic
• 89 per cent glass 

Silicon-based solar panel recycling 

There are several steps in the process of recycling silicon-based solar panels. 

1. The process begins by dissembling the solar panel to separate aluminium and glass parts. 95 per cent of this glass can be reused while 100 per cent of the metal parts can be reused to remould cell frames.
2. Next is thermal processing. The remaining materials are heated up to 500 degrees causing the small plastic parts to evaporate, so that the modules can be separated – roughly 80 per cent of the modules can be reused.  
3. The melted plastic can now be used as a heat source for future thermal processing.
4. Now that the silicon wafers are fully exposed, they are etched away using acid, before being melted to be used again for manufacturing new silicon modules – 85 per cent of the silicon is recycled and 15 per cent is lost during the recycling process. 

Thin-film solar panel recycling 

Much like silicon-based solar panels, thin-film panels have several steps in their recycling process but the process is more complex.

1. The first step involves throwing the thin-film solar panels into a shredder.
2. The panels are then put through a hammermill. Particles need to be reduced to 4-5mm, so that the lamination holding them together breaks. 
3. After the above processes, both liquid and solid materials remain – unlike silicon-based panels, where only solid remains. These materials are separated using a rotating screw.
4. Liquids are put through a precipitation process. What remains from this process undergoes metal processing, which separates the semiconductive materials. 
5. The solid semiconductive material is separated using a vibrating surface. 
6. The remaining matter is rinsed and, now, all that remains is glass. 
7. 95 per cent of the semiconductive material and 90 per cent of the glass is reused.

Firstly, recycling solar panels is completely free for UK homeowners and manufacturers are required by law to dispose of the panels.  

Solar panel manufacturers and importers are required to join a Producer Compliance Scheme (PCS) – this ensures solar panels are recycled properly. In the UK and EU, solar panels are classified as e-waste and must comply with the Waste Electrical and Electronic Equipment (WEEE) regulation, which aims to reduce the amount of electrical goods sent to landfills. 

The government-approved PCS scheme, PV Cycle recycles domestic solar panels for free. French waste management company Veolia has teamed up with PV Cycle to bring Europe its first dedicated solar panel recycling plant, which opened in July 2018. 

Domestic solar systems of up to 20 panels can benefit from the free recycling scheme – more than ideal as most UK households install somewhere between 10 and 16 panels. However, if you do have more than 20 panels, PV Cycle will still recycle them, but you will incur a collection fee. 

Homeowners need to do very little, thanks to EU regulations. Your solar panel installer is legally obliged to arrange the removal of your solar panels. They may use the government-approved Distributor Takeback Scheme (DTS) instead of providing a takeback service. Solar manufacturers can join the scheme and the fees they pay go towards financing collections from designated collection facilities. 

Homeowners needn’t worry about any waste being left behind, as your manufacturer will remove all parts including the mounting system. Solar mounting systems are 100 per cent adjustable and reusable too; you should speak to your installer to establish whether you could use your mounting system for a new solar panel system.   

Benefits of recycling solar panels:

• By recycling solar panels, you’re not contributing to landfill which is already a major climate change issue
• The majority of solar panels materials can be reused and repurposed as new solar panels 
• Recycling solar panels creates green job opportunities. In the very near future, the world will need a large infrastructure of solar panel recycling facilities and this will create job opportunities globally