South Australian company Praxis Aeronautics has been developing its solar UAV technology since 2016 and is building a demonstration drone to display at the Australian International Airshow and Aerospace & Defence Exposition from February 26 to March 3.

Early testing has shown the solar wings can extend drone flying time from three hours to more than nine hours.

Praxis is already in discussions with major drone manufacturers in the United States about forming partnerships to supply their solar wings and hopes to have an agreement in place so it can begin manufacturing test wings in the coming months ahead of its first commercial sales by the end of the year.

Praxis co-founder and Director of Innovation and Manufacturing Cameron Donaldson said having the solar cells built as part of the wing rather than affixed to it solved the power to weight and fragility problems associated with previous solar drone designs.

He said improvements in battery technology was needed to allow the solar wings to keep a drone in the air around the clock.

“When you get to that whole day of flying stage then the next milestone will be drones that can fly through the night and that requires a huge jump forward in battery tech,” Donaldson said.

The Praxis wings were initially designed using traditional silicon solar cells but wings using lighter, thinner and more efficient – and more expensive – gallium arsenide cells (GaA) were developed in 2018.

The Adelaide-based company is now working with four cell manufacturers to provide options at different weights, efficiency and price points for potential partners. Initial costs range from $4 a watt at 25 per cent efficiency through to $400 a watt at 32 per cent efficiency.

“The finish is the same regardless of what kind of cells we use, but the weight is slightly different,” Donaldson said.

“What we’re finding is the cost of GaA cells is prohibitive for a number of the commercial uses but with defence it’s not really cost that’s been holding them back, it’s how rugged you can make them.

“It’s a waterproof product so we’re also talking to companies about putting it on unmanned surface vessels, which are the equivalent of drones for the water.

“We also see applications in things like equipment cases with solar cells embedded for charging hardware like drones when they are being carried around.

“Defence has a huge problem with batteries at the moment – everything they have is …