The Australian Army is just a couple of years away from potentially ditching the burden of heavy batteries thanks to the development of solar-powered backpacks.
Soldiers have recently tested out the flexible SLIVER solar-cell technology on a 72-hour training mission, giving it the go-ahead for commercial sale.
The six centimetre-long silicon cells might be small – at 1.5 millimetres wide they are thinner than human hair – but when combined they can power all sorts of electronics for years, from GPS devices to night-vision goggles.
ANU professor Andrew Blakers – who heads the Centre for Sustainable Energy Systems, which developed the technology – said the "backpacks" could not only lighten a soldier's load but extend the life of a mission.
"If you're carrying fewer batteries you either have a lower weight or you have the same weight but more endurance," he said.
"I've heard soldiers sometimes carry kilograms of batteries. If you can eliminate most of those batteries and replace them with rechargeable ones, you can save quite a lot.
"On a long mission, the solar panel does not wear out, it just keeps going and going, so you can have electric power days into a mission – or weeks or months."
While full sunshine was best, the solar panels could limit or even eliminate the drain on batteries during cloudy weather, he said.
The technology has been developed as part of the $2.3-million Defence Science and Technology Organisation project in collaboration with the CSIRO and defence and security systems company Tectonica Australia.
With testing out of the way the university is set to commercialise the project outcomes with industrial partners.
While the solar cells are likely to hit the military market in the next two to three years, they, like many armed forces resources, are expected to attract a much broader customer base.
"There is a vast number of civilian applications for something this lightweight and flexible," Professor Blakers said.
"Soldiers in the field are not a lot different from bushwalkers in the field – you don't want to carry a glass module in your backpack."
ANU scientists originally developed the cells with glass – but their flexibility got the centre thinking about their potential with plastic.
The result is a flexible, lightweight technology that can be weaved into fabric, such as the wearable backpack-style technology tested by soldiers, or as a material that can be folded akin to a stack of cards and then deployed.
Professor Blakers said the panels could also power remote sensors, like micro cameras, for years.
"You can't do that with a battery."