Risks and rewards of aluminium in solar panels
Aluminium could become a big PV polluter, but it’s also easy to recycle.
As the price of solar power plummets, the uptake of solar panels and rooftop solar is booming, which will make it easier to mitigate climate change.
But the materials and processes needed to build solar panels (or PV, photovoltaics) are not carbon-free. Research from the University of New South Wales (UNSW) points out that the aluminium in solar panels will need to be made sustainably to minimise panels’ emissions.
“Lots of people get focussed on silicon, and they talk about the silver,” says Alison Lennon, a UNSW researcher and chief scientist at Sundrive Solar.
“But when you actually install a PV system, the modules have got to have frames. And then you’ve got to put the modules onto the roof, and often there’s a tilt, and there’s a lot of aluminium that goes in all that railing.”
Other parts of the kit, such as the casings for inverters, are also often best made with lightweight, waterproof aluminium.
Unlike the case for more precious metals, there isn’t a predicted shortage of aluminium. But the researchers caution that aluminium needs to be found and purified in more sustainable ways than it currently is.
“There’s actually quite a lot of aluminium in the Earth’s crust,” says Lennon. “In Australia, we have enormous amounts of aluminium resources, or bauxite. It’s more a matter of the globalwarming potential of refining all that bauxite into aluminium, because it requires so much energy.”
Currently, a lot of the world’s bauxite is refined in China, using fossil-fuel power. Lennon says localised aluminium production, particularly in Australia, could be much less carbon-intensive.