When it comes to renewable energy, there are many great sources. Whether it’s solar, wind, or something else, though, we need a lot of it. Factories around the globe are rising to the challenge to provide what we need.
We can build plenty of new solar panels, of course, but we need to think about what happens when they reach end of life. As it turns out, with so much solar now out in the field, a major new recycling industry may be just around the corner.
Crunch ‘Em Up
Solar panels are great at harvesting energy from the sun, but they don’t last forever. They can get damaged or smashed, or simply age out. Most panels are rated for a service life of 25 years. The solar boom really took off in the early 2000s, and has gathered steam ever since. That means that we’ll soon face an avalanche of solar panels that are ready for retirement.
Like so much modern tech, solar panels wrap up a bunch of expensive and exotic materials into one fancy product. The photovoltaic cells that produce power from the sun are made using materials like silver, copper, and aluminium, all of which are valuable. The cells also use plenty of polysilicon, which is expensive to produce. Other trace materials can include tin and lead used in solder connections, though hazardous waste regulations have reduced this in recent years.
The problem is that all these fancy materials can be difficult to separate out. Copper wiring can be cut off the back of panels relatively easily, and aluminum frames stripped off. However, all the other materials require more processing.
Currently, the bulk of solar panels that are recycled are basically shredded and treated as relatively impure crushed glass, referred to as glass cullet in the industry. Combined with the copper wiring and aluminium frame, recyclers can expect to get around $3 a panel for their efforts. That doesn’t stack up well against the cost of the process, which can be anywhere from $12 to $25 a panel when transport and processing costs are stacked up.
These high costs mean that many solar panels are simply sent to landfill instead. At the present time, only around 10% of solar panels are recycled in the US.
New Processes are the Key
The trick to recovering more from solar cells is to take more care in the recycling process. One method is known as the FRELP process, for “Full Recovery End of Life Photovoltaic” process. It uses a hot knife to carefully separate out the silicon cells from the glass and plastic of the panel, which lets each component be processed separately. Chemical processes can then be used to separate out high-value silver and copper, rather than leaving these materials churned up with the glass. The hope is that the silicon recovered could be of good enough purity to be reused in solar panel production without requiring expensive repurification steps.
Waste management company Veolia has also been working in this area, running a commercial-scale plant in France since 2018, and a newer test project in Germany this year. Similar to most processes, the wiring, cable panel, and aluminium frame are all removed, in this case by robots. Then, the PV panel itself is chopped into small tablets, ground up, and the glass separated from the metal content with an eddy-current separator. This allows for efficient recovery of the raw materials, rather than simply shredding the whole panel and mixing all the precious metals and silicon up with the glass. Veolia hopes to continue developing its process to the point where it can reliably recover high-purity silver and silicon from the panels, to be reused in the production of new panels. The company hopes to step up its operations to the point where it can recycle all solar panels that are being decommissioned in France.
An Industry Set To Boom
The global solar panel waste stream is set to boom. At the end of 2016, there were around 250,000 tons of waste panels, but that’s expected to balloon to over five million tons by 2050. As more solar capacity is installed, it locks in a larger waste stream for the future.
This giant waste stream is quickly becoming a resource ready to be tapped. Rather than running a silver or aluminium mine, companies will compete to get their share of a waste stream full of precious metals. The trick is in perfecting the techniques to extract and purify that metal in a clean and cost-effective way. Research firm Rystad expects the solar recycling industry to be worth $2.7 billion by 2030, and $80 billion by 2050, up from a comparatively-miniscule $170 million today.
Mastering the recycling of solar panels and wind turbines will be key to ensuring we have the renewable power we need into the future. Thus, if you’ve got some creative ideas on how to recover materials from solar panels, there’s plenty of scope to make money at it in the coming years!
Banner photo: “Installing solar panels” by Oregon DOT.
(Yeah, we know, but “installation is in the reverse order of removal.”)