We cover our rooftops with solar panels and encourage everyone else to do so. Australia has the highest per capita take-up of rooftop solar. However, these things have a lifespan, and there comes a time when they need to be replaced by more efficient modules. What happens to old, discarded solar panels? Many are reused, but some are discarded and end up in landfills. This is not an environmentally friendly action, polluting land and water. Many environmentalist are concerned about solar panels ending up in landfills.
A solar panel consists of aluminum, glass, copper, and silicon. Aluminum, glass, and copper are easily recycled, but what of the silicon — ten thousand tonnes a year in Germany alone, and this figure will rise.
Now there may be an answer from German researchers: “The process for recovering the silicon material from discarded solar PV modules was developed by a working group at Fraunhofer CSP, together with Reiling GmbH & Co. KG, and backed by funding from the German Federal Ministry for Economic Affairs and Climate BMWK. The resulting recycling process is able to recycle all crystalline silicon solar PV modules regardless of the manufacturer and origin.
“Crystallisation is carried out with 100% recycled silicon without the addition of commercial ultrapure silicon, and the wafers are then fabricated into PERC solar cells at Fraunhofer ISE’s PV-TEC. The resulting PERC solar cells delivered a conversion efficiency of 19.7%.”
According to Wikipedia, PERC solar cells are: “Passivated emitter rear contact (PERC) solar cells consist of the addition of an extra layer to the rear-side of a solar cell. This dielectric passive layer acts to reflect unabsorbed light back to the solar cell for a second absorption attempt increasing the solar cell efficiency. A PERC is created through an additional film deposition and etching process. Etching can be done either by chemical or laser processing.”
It is expected that this technology will spread and allow greater reuse of the constituent materials of a solar panel, and also reduce the arguments that make some oppose renewable energy (obviously, they have never seen the slag heaps around coal mines and power stations). A lot less solar panels are going to end up in landfill.
I don't like paywalls. You don't like paywalls. Who likes paywalls? Here at CleanTechnica, we implemented a limited paywall for a while, but it always felt wrong — and it was always tough to decide what we should put behind there. In theory, your most exclusive and best content goes behind a paywall. But then fewer people read it! We just don't like paywalls, and so we've decided to ditch ours. Unfortunately, the media business is still a tough, cut-throat business with tiny margins. It's a never-ending Olympic challenge to stay above water or even perhaps — gasp — grow. So ...
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