Improper solar module disposal is a problem – but not a risk to human health

The end-of-life plan for the millions of solar panels installed on rooftops and in paddocks around the country – the other side of the coin to Australia’s world-leading solar success story – is a work in progress.

At this stage, Australia has just one dedicated solar panel recycler – Adelaide-based Reclaim PV – with more and more promising leads emerging from research coming out of various universities and spurred by backing from ARENA.

But what of the PV modules that inevitably wind up in landfill? A new study led by the International Energy Agency has modelled the highly undesirable outcome that significant amounts of solar panels get dumped, in-tact, and it found no significant risk to human health.

The IEA research program, in which Australia has been a participant, compared predicted exposure in soil, air, groundwater and surface water of hazardous chemical elements found in small quantities, such as lead in crystalline silicon modules.

According to the Australian Photovoltaic Institute, or APVI, screening-level methods employed in the report are designed to be used to establish a more complete set of results for any other chemicals of potential concern on commercial PV modules.

Overall, the report found cancer risk and non-cancer hazards to be below screening thresholds for all assessed chemical elements, even in scenarios where large amounts of PV modules were sent to landfill, with no recycling.

“The international team looked at worst-case scenarios to explore maximum possible risk to human health and found no significant hazards with managed disposal of solar modules,” said Dr Jose Bilbao, the UNSW-based Australian expert representative to the IEA on the study.

“Although this report focuses on the potential health risk from disposal of PV modules in landfills, we know that recycling end-of-life PV modules further reduces environmental impacts and resource depletion,” he said.

And the study is careful to stress that this finding is in no way an endorsement of sending used PV modules to landfill.

According to the Australian National University’s Andrew Blakers, the inherent recyclability of solar panels, and their ability to be broken down and separated into existing recycling streams, should make it relatively easy to sustainably manage PV panels at end of life.

“Firstly, the aluminium frame and cables are removed, and join much larger metal recycling streams. A simple method of recycling silicon PV panels is thermal decomposition,” Blakers writes.

“Heat causes the thin encapsulating plastic to evaporate and the panels falls apart. The evaporated plastic is burnt to provide heat and to eliminate emissions of gases (apart from small amounts of steam and carbon dioxide). The glass adds 40% to the existing glass waste and recycling stream.

“The residual silicon and conductive metals are small (one part in ten thousand) additions to much larger existing ceramic and metal waste streams.”