Researchers at the University of New South Wales have made a breakthrough for renewable energy production, demonstrating for the first time the ability to produce electricity from radiant infrared heat sources.
Moonlight isn’t bright enough to generate power, but harvesting renewable energy through infrared light might be the key to powering your home through the night.
An emerging technology which generates night-time solar energy could be powering our home appliances while we sleep within five years.
The The UNSW team was nominated for the ANSTO Eureka Prize for Innovative Use of Technology. (Supplied)
Radiant infrared heat sources are surfaces which emit infrared radiation to directly heat objects or people, without heating the surrounding air.
The new device allows scientists to capture the heat difference in the atmosphere before it would have otherwise been lost into outer space.
The process of building the device
“What we did was we made a semiconductor device … it takes advantage of that radiant heat that’s leaving the Earth, and as that light is emitted, it generates some electricity,” team lead Ned Ekins-Daukes told ABC News.
The device is the size of an entire laboratory at UNSW and is still in its infancy and can only generate about 100,000 times less than that supplied by a solar panel.
“What we’ve done at the moment, could power a wristwatch from your own body heat,” Professor Ekins-Daukes said.
“If you wanted to put this on your roof and power meaningful appliances, then you’d be able to maybe power your Wi-Fi at night from this.”
Thermal imaging cameras capture how much radiation there is at night.
“In the same way that a solar cell can generate electricity by absorbing sunlight emitted from a very hot sun, the thermoradiative diode generates electricity by emitting infrared light into a colder environment,” study co-author Phoebe Pearce said.
The research team took infrared photos  inside a lab. (Supplied)
“In both cases the temperature difference is what lets us generate electricity.
“Because this was really the first experimental demonstration, it wasn’t that we’re trying to reach the maximum possible efficiency.”
Professor Ekins-Daukes said due to physics it was expected the technology would always collect about a 10th to a 100th of the power of solar.
“But it does give us a bit of electricity when we’re asleep, and we tend to use electricity when we’re awake,” he said.
Future plans for the technology
The team’s inspiration for creating “night-time” solar energy was largely fuelled by technologies used in high-end night-vision goggles.
“Using kind of those same material systems in reverse, emitting the thermal radiation rather than absorbing it, is how we generate power,” experimental demonstration lead Michael Nielsen said.
A thermoradiative diode has been shown to be able to generate power from the emission of infrared light. (Supplied)
At the moment the new device can only be used within a laboratory.
“There’s a little more optimising to do before maybe it’s used terrestrially, but we are working to get these on a spacecraft to satellite in the next couple of years,” Dr Nielson said.
Using this technology to power satellites in space is set to be the next phase, which will help fund further development for use in everyday appliances.
The UNSW team was nominated for the ANSTO Eureka Prize for Innovative Use of Technology.
It’s considered the ‘Oscars of science’ awards by Australian scientists and saw 55 finalists nominated for 19 different awards.