Solar waste is a problem that’s yet to reach us at scale due to the lifecycle of solar panels themselves, but eventually, we can expect a major recycling effort and the good news is that much of their components can already be recycled.
Considering most solar panels have been installed within the last decade and with the average lifespan of a PV (Photovoltaic) solar panel being around 30 years, landfills are yet to fill up with this huge amount of renewable waste.
But with 60 billion tons of PV waste expected by 2050, is it possible to recycle it all?
More importantly, for an industry that’s all about sustainability, how sustainable are solar panels at the end of their life?
Are Solar Panels Recyclable?
Thankfully, up to an estimated 80% of the components of a solar panel can already be recycled.
Silicon solar modules which make up 95% of the market comprise glass, plastic and aluminium, all of which are widely recycled.
There are two major types of domestic solar panels currently on the market, these are silicon-based panels and thin-film panels.
Silicon panels, the more common type, are much easier and less labour-intensive to recycle.
How are silicon-based PV panels recycled?
To avoid overcomplicating things, here is a summary of the steps involved in recycling silicon-based solar panels:
- Separating the panels – the aluminium frame and protective glass frame can be recycled. 100% of the aluminium can be remoulded into a new frame and 95% of the glass can be reused or recycled.
- Thermal processing – the rest of the unit, comprising mainly of solar cells is heated to around 500°C to separate the bindings between cells. Any plastics within this will evaporate at this temperature.
- Finally, the silicon wafers are etched away using acid. These are melted into reusable slabs. Any broken wafers are also melted to be used again. This gives an 85% recycling rate for the silicon within the solar panel.
How are thin-film solar panels recycled?
Unlike silicon panels, thin-film panels are thinner flexible panels and therefore need to be shredded.
Here is a brief summary of the steps involved in recycling thin-film solar panels:
- The panels are shredded – at 4-5mm in size the lamination coating the panels will break and can be more easily removed. This leaves a substance made of both solid and liquid materials.
- The solids and liquids are separated. This is done by putting them into a rotating screw which allows the liquid to drain out and keep the solid parts together.
- The liquids go through a precipitation and dewatering process. This ensures the purity of the liquids.
- These liquids then go through metal processing. This completely separates the different semiconductor materials. On average 95% of the semiconductor materials are re-used.
- The solid materials are put on a vibrating surface. This removes so-called interlayer materials that contaminate it.
- The materials are rinsed. Once rinsed what is left is pure glass and this is relatively easy to re-manufacture.
Why do we need to recycle solar panels?
Other than the obvious reason of not wanting to send huge amounts of waste to landfills we need to consider the precious and finite materials used to make solar panels.
Resources in the future will become more limited and the cost of these resources will continue to rise.
According to the International Renewable Energy Agency (IRENA) by 2050 16% of global electricity will be fuelled by the sun, so the necessary infrastructure to recycle is imperative.
Other reasons recycling solar panels is important
- Increased costs in making panels will ultimately be passed on to the consumer.
- Gallium and indium used in the production of solar panels are steadily depleting resources. Sending such finite resources to landfills is not only toxic but is not profitable and will see us eventually run out of these rare elements.
- Employment opportunities in green jobs in the way our economy needs to go. The solar panel recycling industry is currently a fairly new one. The bigger it gets the more jobs will be created.
Legislation to help solar panel recycling
In the European Union, The Waste Electrical and Electronic Equipment Directive (WEEE) has helped to found a members-based organization called the ‘PV Cycle’ to help build more of this necessary infrastructure.
Under EU regulations your installer is now legally obliged to take back old solar panels or fund a take-back scheme.
The aim of this is to help take the pressure off the consumer to recycle their old panels.
In the UK, similarly, solar panel companies must join a Producer Compliance Scheme (PCS), such as the government-approved PV Cycle to ensure all solar panels are recycled in the correct way.
The typical lifespan of a solar panel
Most solar panels will come with a warranty of 25 years, with a 20% drop in efficiency in that time.
However, if looked after it is very likely a solar panel could live for many years after this, just running at a lower efficiency as the years go on.
According to the IRENA the average solar panel should last for 30-40 years.
Make your solar panels last as long as possible by monitoring their efficiency.
If you see any sudden drops in efficiency, you can get the problem fixed as soon as possible and hopefully avoid more problems down the line.
How much does recycling solar panels cost?
For the consumer, the cost to recycle their solar panels is exactly £0.
This is because installers in the UK and within the EU are legally obliged to have a take-back scheme set up to ensure the efficiency of solar panels being recycled.
For the installers and manufacturers, the cost is about £8-16 per module according to Gavin Heath of the National Renewable Energy Laboratory.
However, there does need to be more research done into this as the industry of recycling solar panels becomes more widespread.
Is recycling solar panels profitable?
The question of whether recycling solar panels is profitable or not is an important one because it indicates if recycling will expand and how quickly that will happen in the future.
We have all been sent a new phone in the past because it is cheaper to make a new one rather than repair and recycle the old one.
The good news is IRENA estimates recycled materials from old solar modules will be worth $450 million by 2030 which would fund around 60 million new solar panels.
Recycling solar inverters
Within your solar system, it’s not just the panels that will need recycling.
The lifespan of your solar system should be around 30 years but the inverter, which is an integral part of harvesting solar energy, has a much shorter lifespan and will need to be replaced. Possibly serval times.
High-quality inverters can last up to 15 years, whereas cheaper versions may only last 5 years. Recycling them too is therefore important.
Solar inverters are recycled by removing the hazardous and valuable materials, and then scrapping the reusable parts.
Metals make up 60% of the inverter, 90% of which can be recycled. This leaves the Printed circuit board assemblies (PCBA) of which 65% can be recycled.