Finding new life in dead solar panels

Australians know a thing or two about solar: we have more panels per person than anywhere else in the world. But what happens when they stop working?

Most panels are viable for 20-odd years, meaning early installations are already turning to waste. One million tonnes worth of dead panels could enter the waste stream by 2050, and that’s just in Australia.

But those panels are full of precious and critical minerals, including silver, copper and especially silicon. How do we keep them out of landfill?

For Swinburne’s Professor Akbar Rhamdhani, the answer is simple: recycle them to make new panels. 

“Silicon is a critical mineral, and we need very high-grade versions of it to produce more solar panels, along with many other technologies,” he says.

Recycling has the added benefit of using less energy and carbon to produce panel-grade silicon. 

“In a traditional process, we use carbon and extremely high temperatures to reduce raw silica to metallurgical-grade silicon. It’s very energy intensive and takes a lot of time. Recycling can bypass this,” says Professor Rhamdhani.

But recycling is not without its challenges. It still requires a lot of energy and time, and the silicon must again be made extremely pure—up to 99.99999%. It also requires manual labour to dismantle the panels and remove wires. 

Professor Rhamdhani and his team are working towards a future where much of this work is done in bulk by robots, with processing powered by green energy and electricity.

“We are developing a process that is quite clean, with a no or very low carbon footprint,” he says.

Tackling a global problem

Professor Rhamdhani won't be working alone. He will manage the project together with a consortium of partners across four countries: Australia (Swinburne), India (IIT Hyderabad), Indonesia (Gadjah Mada University and BRIN, the country’s national research agency), and the USA (Sadoway Labs Foundation). The international program is known as Zero-Carbon and Circular Solar PV Recycling (Si-Zero).

“This research program is the first of its kind in the world. It brings together international expertise to develop zero-carbon processes for recovering high-purity silicon and other valuable materials from end-of-life solar panels, strengthening the foundation for a sustainable and circular solar industry,” says Dr Bintang Nuraeni, a Swinburne researcher involved in the program. 

International collaboration is critical, because the global waste stream for solar photovoltaics (PV) is set to reach 78 million tonnes by 2050. In countries like Indonesia and India, the efforts could make solar more accessible at lower prices.

“Recycling end-of-life panels can reduce import dependency, cut production costs and lower environmental impact,” says IIT Hyderabad’s Ashok Kamaraj.

“Establishing silicon recovery infrastructure will support a circular economy, strengthen domestic manufacturing, and align with India’s Make in India, clean energy and sustainability goals.”

Drawing on international know-how

IIT Hyderabad brings deep technical expertise in high-temperature processing. Along with local industry partner Greenko, they will develop new methods like electro slag refining.

The project also aims to help partners become regional leaders in solar panel production and recycling, according to BRIN’s Professor Widi Astuti.

“Regionally, [this initiative] positions Indonesia as a hub for PV recycling technology in Southeast Asia, strengthening the Indo-Pacific collaboration in renewable material recovery,” she says. 

“Through collaboration, Indonesian institutions gain access to frontier knowledge, advanced instrumentation and experimental methodologies,” adds Gadjah Mada University’s Professor Himawan Tri Bayu Murti Petrus.

The collaboration builds on innovations coming out of Swinburne, too. A novel, electrically enhanced refining process developed there allows for the selective removal of impurities in silicon. 

That aligns with a key strength of the project’s US partner, Sadoway Labs. The not-for-profit foundation uses extreme electrochemistry—at temperatures above 540°C—for industrial decarbonisation.

“There is no formula or recipe for generating creative solutions, so we must cast our net as wide as possible. This means bringing together researchers from diverse backgrounds into a collaboration where all are valued,” says Sadoway Staff Scientist Dr Matthew Humbert.

With funding secured, foundational work is set to commence. The project will bring in 10 PhD students and five research fellows across the four countries. 

Prof Rhamdhani’s initial focus will be on fundamental research, ensuring the process is optimised in theory before scaling up demonstrator technology. 

“It’s very exciting to be working on such a big project. We have the potential of making significant changes in the industry, and we’re up to the challenge.”