Recycling process for photovoltaic solar panels

Recycling solar panels - a growing need

The need to reduce carbon emissions to slow runaway climate change generates demand for renewable energy, and rooftop solar power generation is the most accessible option available to the average homeowner. In 2022, North America was predicted to rise to more than 400 GW by 2030 (source: Association of Solar Energy Industries). But current figures indicate that solar photovoltaic (PV) capacity is approximately 219.8 gigawatts (GW) with the solar industry experienced significant growth in 2023 in the United States, with a total of 26.3 GW of new PV capacity installed, marking a substantial increase compared to previous years and Canada's solar PV capacity has also been expanding.

While rapid growth and continued demand for PV and lithium-ion home solar batteries is good news in terms of reducing greenhouse gas emissions right away, the industry does have an ecological impact that needs to be recognized and managed. 

Because the average solar panel lifespan is between 25 and 30 years, which predates the massive surge in popularity and production, we have not yet had to face the same surge in decommissioning of older solar arrays. As solar panels on homes becomes a more popular choice in North America, the problem is a growing one for finding an effective way to recycle precious resources found in solar panels.

According to the Solar Energy Industries Association (SEIA), currently less than less than 1% of end-of-life solar panels are decommissioned each year. However, as age catches up with those older panels, we will begin to see the same bell curve of waste panels match what we saw in production.

Because of that, photovoltaic solar panels could represent more than 10% of the global tonnage of electronic waste by 2050, which amounts to between 60 and 78 million metric tons. And for the solar power generation industry to continue to be viewed as ‘clean energy’, it cannot leave a trail of toxic waste such as lead and heavy metals in its wake.  

The recycling process for photovoltaic solar panels

The current market is dominated for the most part by two types of photovoltaic panels: those with silicon-crystalline modules and panels with thin-film modules. Silicon-crystalline modules are the most widespread, accounting for 90-95% of global production. The latter generally use a mixture of materials consisting of glass (76%), polymer (10%), aluminum (8%), silicon (5%) and copper (1%).

The vast majority (between 95% and 99%) of these components can be recycled. Glass recycling is already a well-established industry, as is aluminum, copper, and plastic. The challenge for mass recovery of raw materials lies in the profitability, or more accurately - the lack of it.

While aluminum and copper (and to a lesser extent glass) have demonstrated economic viability in recycling programs, plastic has not as it is not currently profitable. And it is questionable just how much of the plastic we send for recycling actually ends up being recycled. It is suspected and very likely, that a lot of plastic we put to the curb in recycle bins is just being shipped to the dump in a more noble looking truck. 

As for other integrated materials and components like inverters, racks and batteries, they can also be recycled with electronic waste or similar scrap metal. Batteries can be processed under existing battery recycling programs.

PV panels contain traces of toxic metals such as silver, lead, cadmium, tin, all of which are more difficult to recycle. Even though such toxic elements represent only a very small amount of materials in PV panels (less than 0.1%), their end of life represents a very real challenge.

What are the benefits of recycling end-of-life solar panels?

The increased stability of the supply chain, the reduction of negative environmental impacts and costs, new and expanded market opportunities, the ‘green’ image and jobs are some examples of the benefits of developing this sector. Recycling PV modules makes it possible to recover high-value materials (e.g. silicon, indium, silver, tellurium, copper) for use in the manufacturing of new panels, or they can be repurposed in commodity markets.

Recycling solar panels means saving space in landfills, limiting potential pollution of soils and groundwater, reducing greenhouse gas emissions, and the recovery of valuable natural resources. The recycling pathway therefore greatly reduces environmental impacts by injecting materials into the market and reducing some need for extraction, refining and transportation of raw materials (Curtis et al. 2021b).

What are the challenges associated with recycling PV solar panels?

While there are many societal advantages to recycling PV panels, economics is the biggest hurdle. The cost of recycling the various components of solar panels tends to be prohibitive, while many landfills charge minimal or even no cost per tonnage for disposal. 

According to Garvin Heath, a senior scientist at the National Renewable Energy Laboratory, it currently costs $20 to $30 to recycle a single solar panel, compared to $1 to $2 to send it to a landfill. So PV recycling in the U.S. is not optimized for cost-effective material recovery, and there are simply no processing facilities in Canada.

In Europe, waste management legislation was amended in 2012 to include photovoltaic modules, which obliges companies in the photovoltaic sector to collect and recycle their end-of-life products. Legislating the recycling of materials removes profit from the decision-making process of what to do with waste materials, and it builds that recovery cost right into the initial purchase price.  

According to experts, the only solution is an aggressive and coordinated effort to establish government regulations and implement private sector investments that enable the recycling of clean energy technologies on a large scale.

Government-funded research and analysis is needed to study the value and markets for recovered materials, module recycling technology and infrastructure needs, permit requirements and responsibilities, and the overall costs associated with recycling PV modules.

What is needed to facilitate the recycling of PV panels in North America?

It will likely take legislation to put in place any meaningful solar panel recycling initiatives in Canada and the US. As in Europe, it either needs to be mandated, or made more expensive to dump panels rather than repurpose them.

 Revenue can also be generated through the sale of recovered materials in commodity markets. In fact, the Environmental Protection Agency (EPA) estimates that by 2030, the cumulative value of recoverable raw materials from end-of-life panels worldwide will be about $450 million, which is equivalent to the cost of raw materials currently needed to produce about 60 million new panels. 

End-of-life management of solar panels:

While regulations exist in several places around the world such as Europe and Japan for example, in the United States and Canada there are no federal laws or regulations that specifically address the recovery of PV modules by recycling. 

Some southen states have systems in place to facilitate the recycling of PV panels under the SEIA's National Recycling Program, which also allows a few Canadian recycling companies to ship waste panels to these recycling facilities. 

In the absence of a truly functional PV recycling policy, North Americans risk sending millions of solar panel components and tons of potentially toxic products to landfill in the coming years. Expanding producer responsibility, which would make manufacturers responsible for the future waste disposal on behalf of their customers, may well be necessary when it comes to recycling. 

In any case, we must focus on the circular economy of renewable energies today. Leaving such important ecological issues to the last minute is not something we can afford to do anymore.