Solar power is experiencing a period of rapid expansion. Since the early 2000s, the adoption of solar panels globally has seen exponential growth, a trend projected to continue for decades. By the close of 2015, the world had installed an estimated 222 gigawatts of solar energy capacity. A recent report from the International Renewable Energy Agency suggests this figure could surge to 4,500 GW by 2050.
However, the solar panels that are crucial to this energy generation aren’t designed to last indefinitely. The solar industry generally sets the standard lifespan for solar panels at approximately 25 to 30 years. This means that some of the earliest installations from the current solar boom are nearing the end of their operational life. Each year, an increasing number of panels will be decommissioned – photovoltaic modules made of glass and metal that will soon accumulate into millions, and eventually tens of millions, of metric tons of material.
“It’s not far in the future that these panels will be taken offline, leading to a significant waste management challenge,” noted Garvin Heath, a senior scientist at the National Renewable Energy Laboratory and an expert in solar power. “It’s becoming increasingly recognized as an issue that demands our attention and action soon.”
As photovoltaic panel installations increase, so does the future need for managing end-of-life disposal and recycling.
Recycling is often seen as the primary solution. However, the current infrastructure for recycling the impending volume of photovoltaic (PV) modules is not yet adequate. “Some infrastructure exists,” Heath stated. “But it’s not particularly well-established at this stage.”
One of the main obstacles is the complex nature of solar panel recycling. Solar panels are constructed from numerous materials, some of which are hazardous. They are assembled using adhesives and sealants, making disassembly a complex process.
“The durability of these panels, their construction methods, and manufacturing processes inherently complicate their de-manufacturing,” explained Mark Robards, director of special projects for ECS Refining, a leading electronics recycler in the U.S. The recycling process involves mechanically dismantling the panels and using acids to separate the crystalline silicon, the semiconductor material used in most PV modules. Heat systems are employed to burn off adhesives, and hydrometallurgical processes are used to extract precious metals.
Robards pointed out that about 75 percent of the material recovered is glass, which is readily recyclable into new products but has a low market value. Furthermore, the composition of recyclable materials is constantly evolving. As solar panel technology advances, manufacturers are progressively reducing the use of valuable components like copper and silver.
“Consequently, the inherent commodity value of these panels continues to decrease,” Robards added. Lower material value reduces the financial incentive for recycling.
Despite these hurdles, ECS has been expanding its solar panel recycling capabilities. “It’s showing moderate growth in the near term, but we anticipate explosive growth from around 2020 onwards,” Robards said, referring to the millions of metric tons of panels expected to be retired.
Investments in Recycling and Cost Reduction
The absence of a consistent supply of end-of-life panels makes it challenging for recyclers to dedicate more resources to solar panel recycling. To prepare for the future surge, the solar industry is initiating training programs for recycling companies. These programs aim to educate commercial recyclers about the materials in solar panels and effective disassembly methods, according to Evelyn Butler, senior director of codes and standards at the Solar Energy Industries Association (SEIA). SEIA is a trade organization representing solar power companies and PV manufacturers.
Butler mentioned that SEIA is also collaborating with recyclers to share data on processed components and materials, aiming to track and predict waste streams.
“We are still in the early stages, but we hope to provide comprehensive industry data within five to ten years,” she stated.
A solar recycling facility provides First Solar, a photovoltaic panel producer, a method to reclaim materials from used solar panels for potential reuse.
Some PV companies are taking a leading role in recycling. First Solar, a major PV provider, has long offered recycling services for its products. Sukhwant Raju, the company’s director of recycling operations, notes that their recycling process has been continuously refined over the years.
“Our company has installed over 100 million modules, but most are still 10 to 15 years away from reaching their end of life,” he said. “As time progresses, our technology costs are decreasing, while the volume of scrap will increase. This provides us with economies of scale.”
First Solar’s long-term goal is to make recycling cost-effective and efficient enough to handle the anticipated influx of decommissioned panels.
“The total cost must be so low that recycling becomes the obvious choice. In the last eight years, I’ve observed a significant reduction in these costs,” Raju commented.
Complementing improved recycling methods, First Solar designs its panels to be easily recyclable. Up to 90 percent of the glass and semiconductor material from their end-of-life panels can be reused in new panels or other glass products.
Regulatory Landscape and Future Outlook
In the U.S., much of the progress in solar panel recycling is occurring without federal mandates. Currently, there are no federal standards or requirements for managing end-of-life PV panels that are not classified as hazardous waste – which is typically the case. Similarly, no major state-level regulations exist for these non-hazardous wastes.
Garvin Heath from the National Renewable Energy Laboratory highlighted that Washington state passed legislation requiring manufacturers to finance the recovery and recycling of panels sold within the state. This is the most advanced legislation on solar panel recycling in the U.S. to date, although full implementation of the regulations is expected around 2021. It’s also important to note that Washington is not among the states with the highest solar energy adoption rates. In California, a leading solar state, similar legislation is still likely several years away.
Outside the U.S., the European Union’s Waste Electrical and Electronic Equipment Directive offers a regulatory model. It mandates that producers finance the end-of-life treatment of solar panels sold in Europe.
According to First Solar’s Raju, similar federal regulations in the U.S. are unlikely in the near future. However, given the massive volume of solar panels projected to become obsolete in the coming decades, experts believe that more comprehensive regulations are inevitable.
“I think it’s only a matter of time,” Raju predicted. “I would be very surprised if we don’t have a similar program in place within the next 10 years.”
