Solar recycling’s glass ceiling – pv journal International

Most of the straightforward wins for PV module recycling have already been achieved. Materials resembling aluminum or metal used for module frames and the copper utilized in wiring may be simply separated from a panel and have well-established recycling markets. The modules may be destroyed at an electronic-waste or different recycling facility and the assorted supplies may be recovered.

While processes of this sort don’t end-of-life modules from the landfill, it results in a discount within the high quality of the supplies obtained and a small probability that they’ll attain the extent of purity required to search out an their means again to a brand new photo voltaic. module or every other excessive worth utility – lengthen the road however fail to create the specified circle. Module manufacturing large Longi has confirmed that it already makes use of recycled aluminum for its frames however sees it as a significant problem to combine different recycled supplies into its provide chain.

To hold the circulation of photo voltaic panel supplies ceaselessly, particular therapy is required, as a substitute of processing them with different waste. In the European Union, PV module waste is presently regulated beneath the Waste Electrical and Electronic Equipment (WEEE) directive. Writing in PV Cycle’s annual report for 2023, managing director Jan Clyncke mentioned that “the WEEE directive isn’t the suitable one for photovoltaic panels. PV Cycle is in favor of a devoted legislative act that solely offers of all renewable vitality tools.”

Such legal guidelines may be vital in making certain that modules go to applicable recyclers. In phrases of expertise, nonetheless, there was encouraging progress from European corporations in the case of changing shredding with a course of that’s extra able to separating supplies.

“We naturally attempt to separate and re-use all of the parts of a module and we discovered that crushing and sequential association isn’t sensible,” mentioned Wolfram Palitzsch, CEO of German photo voltaic recycling firm Luxchemtech. “A sure proportion of the steps within the course of should even be of a chemical nature. Mechanistic processes alone don’t produce pure finish merchandise.”

French PV recycler ROSI is opening its first facility in Grenoble in 2023. It is now planning a second web site in northern Spain, which is anticipated to come back on-line in early 2025, and is working intently with Luxchemtech and companions to can enter the German market. Instead of shredding, ROSI makes use of the method of pyrolysis – heating in an oxygen-poor atmosphere – to interrupt down the polymer encapsulant that holds a module and might extra successfully and cleanly separate the glass cells. and silicon.

Solar glass

Since it makes up the most important a part of the amount of supplies in a PV module, glass will characterize a giant win for photo voltaic producers – ROSI estimates that round 70% of the supplies processed in his Grenoble facility is glass. There can also be a well-established marketplace for recycled glass supplies, which is engaging to producers because of the potential vitality financial savings in comparison with processing uncooked glass materials. The strict high quality and transparency necessities of photo voltaic glass, nonetheless, imply that processing the recycled materials to the required stage is a problem. ROSI has made lots of progress in that path by 2024 and says that the standard necessities for photo voltaic can be a bonus when working with different glassmakers.

“The benefit of photo voltaic glass is that it must be very clear,” mentioned Damien Letort, ROSI’s industrial supervisor. “So if you happen to can separate it properly sufficient, the standard of the recycled cullet glass that we will provide is superb.”

Thanks to its pyrolysis course of, ROSI can separate and ship extremely pure cullet glass again to the glass producers. Letort mentioned the corporate is working with a shopper, a significant European glass producer, to check the standard of its recycled glass materials.

“We made some clarifications with our shopper and we’re very proud of the outcomes,” he mentioned. “We can separate the glass and it is very excessive transparency photo voltaic glass. That’s very attention-grabbing for lots of producers.”

Client ROSI works with manufactures of float glass used within the building business. Letort mentioned that presently, it’s unlikely that the recycled glass materials will likely be utilized in one other photo voltaic panel as a result of a lot of the photo voltaic glass is managed in Asia and transport such a distance isn’t very affordable.

Despite ROSI’s success within the space, Luxchemtech’s Palitzsch warns that the presence of antimony in most photo voltaic glass remains to be an issue in the case of recycling. “I do not know of a single flat glass producer in Europe that may course of a shard with round 2,000 elements per million (ppm) of antimony into PV glass, so it is a problem to know who will purchase extra. antimony glass. sooner or later, and at what value,” he mentioned.

That ought to be a problem for glassmakers relatively than recyclers, Letort mentioned. “We put the photo voltaic panel by thermal therapy and mechanical sorting, and that is the scale of our plant,” he mentioned. “Then it is as much as our shopper to validate that they will take care of the glass and use it of their course of.” He went on to notice that the shopper had made robust progress in working cullets with some antimony, whereas additionally acknowledging the issue.

“ROSI advocates for antimony-free glass in new photo voltaic panels put in in Europe, particularly by the Ecolabel directive, as a result of it opens extra doorways for recycling,” he defined.

Letort regarded on the accountability of ROSI supplying the glass cullet with good transparency, and famous that pyrolysis can harm the transparency if not rigorously managed and that the sorting course of can also be rigorously managed to forestall the stays of silicon or different supplies. “We assure good high quality transparency and shoppers face the transformation of our supplies in their very own course of,” added Letort.

Silver and silicon

Silicon cells are the subsequent greatest goal and are significantly engaging to recyclers because of their silver content material. Here too, a transition from tearing is beneficial. Palitzsch mentioned that shredding and additional processing yielded silicon of about 80% purity. “But 80% purity isn’t actually attention-grabbing for a lot of silicon purposes,” he mentioned.

Solar grade polysilicon producers have very excessive purity necessities – often not less than 6N (99.9999%). And the totally different supplies used for doping and deposition of different layers that make up a working photo voltaic cell can imply that even when ultra-high purity may be achieved, the profile of the remaining impurities could also be totally different from these present in new materials, which requires. additional investigation.

Some high-value silicon purposes have barely much less stringent necessities. Here, ROSI says it is the identical state of affairs as glass.

“We’re at an identical stage for silicon, we’re working with a giant chemical business accomplice that is testing our silicon and proving it really works,” Letort mentioned. “This may be among the finest added values ​​in our course of. We can keep glorious high quality for silicon, it solely goes by tender therapies.

ROSI implements its personal delicate chemical course of to separate the supplies that make up a photo voltaic cell after they’ve been separated, utilizing pyrolysis, from the remainder of the module, leaving it as reusable and high-purity silicon. silver.

Cost problem

The value of PV recycling has lengthy been the largest problem – from convincing undertaking house owners to spend extra money to maintain the supplies out of landfill, to the precise processing and integration of supplies.

Currently, ROSI is paid to offer photo voltaic module recycling as a service, which emphasizes the significance of clear regulation of the sector and the particular laws promoted by PV Cycle and others. As PV waste begins to extend, processes and enterprise fashions for photo voltaic recycling will likely be key to protecting supplies in circulation. “Loads is feasible with the expertise and some huge cash is being invested,” Palitzsch mentioned. “This is likely one of the most vital points: will the expertise funding repay?”