Australia’s Solar Freakin’ Roadway (Sort Of)

Australian construction materials firm Boral is trialling sand used in concrete that’s derived from the glass of discarded solar panels for a major transport project in Melbourne.

Sand is a crucial material for the building and construction industry. According to the UNEP, 50 billion tons of sand is used each year and it is the second-most exploited resource after water. While there’s a lot of it around, not all sand is equal and the sand that is suitable for construction and other purposes is being used faster than it can be replenished by natural processes in some locations. Sand mining can also damage ecosystems.

“Until now we may have considered sand as a common material; it is time to reassess and recognise sand as a strategic material,” said UNEP’s Sheila Aggarwal-Khan in 2022.

Sand is also used to make glass, and the glass face on a solar panel typically makes up the majority of its weight. Given its nature, this glass can be crushed to produce a good-quality sand.

Boral is trialling this sand in a high-profile project – Melbourne’s North East Link; which incorporates 6.5km of tunnels from Watsonia to Bulleen. The Victorian Government says it will enable trips up to 35 minutes faster between Ring Road and the Eastern Freeway.

Boral has sourced the glass sand from ElecSome, a solar panel resource recovery and “upcycling” firm. The glass was crushed and processed at Elecsome’s facility in Victoria, and subsequently blended with up to 50 per cent natural sand.

Assessment of the concrete’s plastic properties (before it has hardened and is still workable) and hardened property testing for compliance with relevant standards has been carried out by Boral, which says has returned excellent results so far.

“We’re excited to be leading the development of concrete mixes containing solar glass sand, an innovative new product that will be used in Victoria’s biggest project in history,” said Dr Ali Nezhad, Head of Sustainability and Innovation at Boral. “The success of this sustainable concrete mix in a commercial project provides an effective pathway for recycling of end of life solar panels and contributes further to sustainability of the construction and building industry.”

More On Elecsome

Elecsome was launched in 2015 and is backed by Ojas Group, which supplies custom cables for the solar energy, wind power, mining, utilities, transportation and construction sectors.

Elecsome claims to have Australia’s first solar panel “upcycling” plant at Kilmany that turns discarded solar panels into (some) higher value products. Its facility has a handling capacity of 5 tonnes per hour. That’s around 250 panels and hour or 1 million panels per annum. The Kilmany facility has been operating since 2023.

The company has also come up with a pre-mix concrete product incorporating solar glass fines replacing a portion of aggregates called SolarCrete.

I couldn’t see any pricing and there’s only “pre-order” options, so it might not be quite ready for prime time yet.

Elecsome’s resource recovery activities go beyond glass. Once the panels arrive at the processing facility, they are categorised for reuse (where isn’t clear), recycling or upcycling depending on the panel type and its condition. Aside from glass recovery and processing:

• The silicon cells are processed to provide PV grade silicon.
• Conductors are re-used in electrical appliances.
• Silver and copper are recovered for use as raw material for other industries.
• Aluminium frames are repurposed for cans (or used to make more solar panel frames).
• Plastics and polymers enter established recycling channels.

While solar panel waste in Australia is and should continue to be minor compared to the all the other waste Australians produce; it’s waste we could do without. It’s good to see modules being diverted from landfill; but the solar panel recycling business is a tough gig.

The “Freakin’ in this article’s title is a nod to an old Youtube video promoting a controversial project in the USA with the goal of integrating solar panels into road surfaces.

Original Source: https://www.solarquotes.com.au/blog/solar-glass-sand-mb3120/