What happens when solar panels stop working?
Do solar panels have any opportunity to be reused?
By the end of 2024, the world's solar generation capacity is expected to reach almost 2,000 gigawatts. Each solar panel consists of silicon, glass, various polymers, aluminum, copper, and several metals that capture energy from the sun. Generally, it is estimated that a panel can last up to 30 years, provided it does not suffer damage. However, questions arise about the fate of the materials when current panels become obsolete and whether we are indeed wasting those resources.
Traditionally, solar panels are believed to have a lifespan of about 30 years, although the reality is more complex. According to experts, panels tend to experience a higher failure rate at the beginning of their life, attributed to manufacturing or installation errors. During their mid-life, very few panels experience failures, while the failure rate increases as they approach the three-decade mark. Nevertheless, it is estimated that less than one percent of operating panels fail before reaching that milestone.
Matt Burnell, founder of ReSolar, a British startup, is researching the reuse and recycling of solar panels. During a visit to a solar park that had 40,000 panels, he observed that 200 were damaged during installation. Burnell took around 50 of those panels and found that most were still within the manufacturers' tolerance margins, despite having some minor imperfections.
Weather also poses a significant threat to the longevity of solar panels. Extreme weather events and harsh climatic conditions can cause degradation. Often, when a panel breaks, repairing the damage is not economically viable.
In addition to damaged panels, many are decommissioned after 25 or 30 years, even if they are not in poor condition. The reasons behind this are mainly economic. As panels age, their efficiency decreases; exposure to sunlight can degrade the adhesive layers, reducing energy generation capacity. The manufacturers' warranty covers a 30-year period, during which they commit to ensuring that the panels maintain a minimum performance of 80%. Once that warranty expires, it often becomes more cost-effective to discard and replace the panels.
Solar parks operate with a limited number of interconnections, each with a strict limit on the amount of energy it can send. Therefore, there is a drive for each park to generate as much electricity as possible. Burnell mentions a solar park in the UK that, after 10 years, opted to replace its panels with more efficient versions, leading to waste of panels that are still functional.
Currently, only one in ten solar panels is recycled, and the majority end up in landfills. The lack of a standardized system to track the fate of panels raises serious concerns, especially with the increase in their disposal in places like California. The legal situation regarding the recycling of solar panels is fragmented, with various regulations varying by state. In some cases, discarded panels must be treated as hazardous waste if they contain heavy metals.
The EPA is working to establish rules that standardize the recycling process, but so far, most panels remain in a limbo without a clear fate. In contrast, in the UK and Europe, regulations require companies to collect and recycle discarded panels.
There are two methods for recovering materials from the panels. A mechanical approach, which is simpler but less efficient, and thermal and chemical methods that aim to separate the components in a way that allows for the recovery of rare metals. However, recycling solar panels faces challenges such as variations in the materials used and a lack of information about the exact composition of each panel.
A promising aspect for improving recycling is the removal of adhesive polymers in the construction of the panels. Recent research has shown that it is possible to create a panel that uses lasers to bond its components, which would facilitate recycling at the end of its life. However, the large number of panels produced under the old system will represent a significant challenge in the future.
In summary, while progress is being made in the reuse and recycling of solar panels, there is still a long way to go to address the issue of the panels' fate at the end of their life cycle.
