Sydney: Australian researchers have made a major breakthrough in "night-time solar" technology. For the first time in the world, researchers from the University of New South Wales (UNSW) has demonstrated how to generate power at night using solar panels.

"In a sense, we've only been dealing with half of the opportunity, when we use photovoltaic solar cells to collect sunlight [during the day]," project leader Associate Professor Ned Ekins-Daukes tells.

After the sun sets and darkness sets in, Professor Ekins-Daukes says the potential for harnessing solar energy remains.

"We get energy from the sun it arrives; it warms up the Earth but then the Earth actually radiates the exact same amount of energy back out into space," he says.

Professor Ekins-Daukes and his team contend that if the flow of this radiant heat could be tapped by a power cell device and converted into electricity, there's "a large and unused spectrum of potential power to be exploited."

So, in a new study published in ACS Photonics, the team used a thermoradiative diode (a semiconductor sensor found in existing technologies like night-vision goggles) to capture photons leaving Earth along the infrared spectrum and converted them into electricity.

"What you're doing is interrupting that flow of radiant heat, which is released every night out into the universe anyway, and tapping off a little bit of electricity from that," Professor Ekins-Daukes says.

Australia is one of the world's biggest adopters of rooftop solar panels. Since 2001, the number of customers with solar panels has ballooned to more than 3 million. And in 2021, there was a record uptake of more than 3,000MW of rooftop solar installed by Australian householders.