As countries around the globe push towards net zero emissions targets, new research has highlighted an area of environmental concern in the production of solar panels.
An Australian study has found that to reach net zero milestones, the world will need almost 60 times more solar power, the production of which could cause "concerning" levels of global warming unless steps to reduce emissions during the panel production process are taken.
Photovoltaic engineering researcher Alison Lennon said part of the problem was the emission-intensive production of aluminium, with solar panel components mainly comprised of aluminium frames, inverter casings, rooftop cells and mounts.
However, Professor Lennon said that even if the solar panel production process continued using non-renewable energy sources, a move towards more solar energy would still be of benefit to the climate.
"There's still benefit … [even] having all the elements to build that solar without the green aluminium, there's still a benefit," she said.
"Australia is actually the largest producer of bauxite, and one of the largest producers of alumina — so there's a real opportunity for Australia to play a big role in this growth of renewable energy."
The study revealed that for the global community to reach net zero by 2050, about 60 terawatts of solar power along with 480 megatons of aluminium would be required.
Currently, there is 0.8 terawatts, or 800 gigawatts of solar available globally.
The China opportunity
Professor Lennon said that in coming years, as countries considered possible carbon border taxes, Australia's high-emissions aluminium would not be as competitive on the international market.
But if Australia could produce low-emissions aluminium, it would be a valuable export and manufacturing opportunity.
She said Australia had the upper hand over countries such as China when it came to greening aluminium production due to the location of our refineries.
"In China, where most of the aluminium is currently produced, it's a little bit harder to do that because all their solar farms are way out west," Professor Lennon said.
"There's a lot of solar resources but their smelters and refineries tend to be on the east coast where it's not as sunny.
"In order to convert their smelters and refineries … they would have to build very large transmission lines from west to east."
Professor Lennon said Australia had four smelters, including one in Tasmania which was hydro-powered and produced less than five tonnes of emissions per tonne of aluminium.
She said all of the mainland Australian smelters were powered by coal, producing "well over" 10 tonnes of carbon emissions per tonne of aluminium.
Sector prepares for renewables
Mining company Rio Tinto last year committed to powering its aluminium assets with renewables by 2030, reducing its carbon emissions by 50 per cent by the same year.
The company is already studying the use of hydrogen to replace natural gas in the alumina refining process in central Queensland, while in Canada where Rio Tinto's smelters are hydro-powered, it is commercialising a process to remove carbon emissions from the aluminium smelting process.
The company also signed a statement of co-operation with the Queensland Government to establish renewable energy in central Queensland.
Rio Tinto aluminium chief executive Ivan Vella said the move showed the company's commitment to making its long-term industrial assets greener.
The company has said switching its Queensland-based Boyne Island and New South Wales-based Tomago smelters to renewables would require approximately 5 gigawatts of solar and wind power, as well as having a guaranteed alternative supply which could be from other energy sources.
Solar technology evolves
Dr Nicholas Aberle from the Clean Energy Council said the study showed the value in traditional smelting transitioning to renewable energy sources, and that technology advances could reduce the need for aluminium in solar panels of the future.
"We are already seeing the emergence of thin-film and printable solar cell technology that would help avoid the challenges identified in this research," he said.
Meanwhile, Smart Energy Council president Steve Blume said there was no cause for concern when it came to aluminium production specifically for solar.
He said solar panels were not in the top 10 uses of aluminium and were not predicted to be, even with increased demand for solar technology.
