Over the past five years, it’s become more likely to see solar panels blanketing a field or shimmering on a rooftop near you. The industry grew by 33 percent each year on average over the last 10 years, with cumulative solar installations nearly doubling in the last five.
That growth will almost certainly accelerate thanks to a big boost in funding from the federal climate bill, which directs $30 billion toward renewable energy over the next decade.
But what will happen when these photovoltaic panels reach the end of their useful life, 25-30 years in the future? Interest in the panel-recycling question has grown alongside the rise in solar installations, but experts say the industry for solar panel collection and disassembly is still nascent and not evenly distributed across the U.S. And the options for reuse and refurbishment — the more sustainable of the circular economy strategies — are even less accessible.
Making solar panel recycling more commonplace will require a mix of technological advances, economic incentives and smart policies at the state and federal levels. And crucially, experts say, all of that behind-the-scenes work must result in a simple, one-stop solution for solar developers and owners, many of whom currently don’t give much consideration to panel recycling at all.
"Let's not make it complicated, because otherwise people are less inclined to recycle," said Evelyn Butler, vice president of technical services for the Solar Energy Industries Association, a nonprofit trade association.
The commercially available resources for solar panel recycling in the U.S. have not advanced significantly in recent years, according to those interviewed for this article.
"There has been quite a bit of activity, but I would say still very slow going as far as its overall growth," Butler said.
Garvin Heath, distinguished member of the research staff at the National Renewable Energy Laboratory (NREL), said a handful of companies — notably First Solar, Cascade Eco Minerals and Solar Cycle — offer end-of-life services to solar developers, but there isn’t yet enough demand for the service to incentivize more growth.
Until economies of scale kick in, solar recycling remains a low-margin business that doesn’t justify investment in new technologies — some of which are available, but not yet implemented commercially, Heath said.
"The reason you do not see more companies doing solar panel recycling is because the economics don’t make sense," said AJ Orben, vice president at We Recycle Solar, one company focused on this activity. "It costs more to break a panel down and recover the raw materials than what the raw materials themselves are worth."
In fact, Orben’s business generates most of its revenue from environmental consulting and other services; the recycling piece of the company is a money-loser.
With the panels it does receive, We Recycle Solar separates the glass from the metals, sending the metals to refineries and shredding the glass before it goes to a processing plant. The semiconductors are melted down and used in future solar applications, Orben said.
Heath said this is pretty common: The metal and glass are the two most common materials recovered from solar panels, with the smaller items — such as the silicon solar cells — rarely finding a second use. At the end of the day, most recycling companies are interested in a single material, Butler said, which means even the recyclers that do accept solar panels might end up extracting one primary material before sending the rest of the panel to another firm.
Laws and landfills
There’s a big regulatory barrier that gets in the way of some potential solar recycling. In most parts of the U.S., solar panels are classified as hazardous waste. This severely limits the number of recyclers willing to accept solar panels, due to tight regulations and testing requirements.
The state of California two years ago reclassified solar panels as "universal waste," a category that is also home to batteries and lightbulbs. Orben said this opens the door for more waste handlers — already permitted for universal waste — to accept solar panels. They may end up just storing the panels and shipping them to a more qualified recycler, but Orben said it creates more opportunities to divert panels from landfills.
Heath said NREL is also dedicating some of its research muscle to policy matters. For one, it is looking into new standards for waste classification. But Heath said it also wants to develop standards for reuse and refurbishment of panels, especially in grid-connected applications.
"That’s a far larger market than the offgrid use of used solar modules," Heath said, referring to the do-it-yourself use of panels on homes, mobile or otherwise. "There are only so many ‘van-life’ vans to put PV modules on."
In other words: Creating safety standards for refurbished panels could allow them a second life in utility-scale solar projects. "That’s something that needs more attention," Heath said.
A rude awakening
Then there is, of course, the problem that most solar owners and developers are not fully up-to-speed on the end-of-life options for panels.
One common misconception, Orben said, is that solar owners will compare the cost of solar recycling to the cost of landfill disposal — a false choice.
"When people are doing their comparisons in terms of costs, they are not doing an apples to apples comparison," Orben said, because in most places it’s illegal to dispose of panels in a landfill (again, thanks to the waste classification). "In reality what they need to be comparing is the cost of recycling to, say, hazardous waste treatment, which is monumentally more expensive."
Heath and Butler both agree that the public also needs a better understanding of the non-recycling options: reuse and refurbishment.
"Within the space of circular economy, recycling has received by far the greatest amount of attention. Recycling is not the only circular economy strategy," Heath said.
Enel North America, a renewable energy company with a global presence, is one solar developer that is focusing on some of those non-recycling strategies.
"What we look to do is extend asset life for as long as possible," said Peter Perrault, the company’s director and head of circular economy. "Just because a PV panel isn't utility-grade performance doesn't mean it can’t be used in an industrial or commercial application. … We always want to extend the useful life of those materials, prior to considering recycling."
Most of Enel’s installations in North America are nowhere near that point, anyway; the oldest was installed in 2012. But Perrault said Enel is committed to panel maintenance — which extends their life — and secondary applications. The company sees it as an essential part of its scope-three sustainability strategy.
Indeed, there are obvious environmental and economic benefits to extending the life of panels, rather than breaking them down and creating new ones. Heath has done some research on this, but said there needs to be more focus on this area — especially on how to make new technologies commercially viable. One such technology could allow recyclers to make use of the crystalline silicon components in panels, Heath said.
"Developing technologies alone does not ensure that those technologies are adopted in the market. And only when they are adopted in the market do we have an improvement in the outcomes," he said. "We can't just invent technologies, we have to ensure they have the right economics." (And not just economics; these technologies need the right policy environments to succeed, too).
The economics of solar recycling or reuse are likely to be an unwelcome surprise for many solar owners, Orben said, because most do not budget for any kind of end-of-life services.
He’s confident that recyclers such as his own company could scale up as demand for the services increases, but he’s not so sure the public is ready to see the price tag.
"They’re in for a rude awakening," Orben said.