Researchers at the University of New South Wales have achieved a breakthrough in renewable energy production, showcasing for the first time the capability to generate electricity from radiant infrared heat sources.

Moonlight isn't sufficiently bright to produce power, but harnessing renewable energy through infrared light could be the solution to sustaining your household through the night.

An emerging technology that produces night-time solar energy might be capable of powering our household appliances while we slumber within five years.

Radiant infrared heat sources are surfaces that emit infrared radiation to directly warm objects or individuals, without heating the surrounding air.

The new device enables researchers to capture the heat variance in the atmosphere before it would otherwise dissipate 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 early stages, capable of generating approximately 100,000 times less power than that provided 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.

"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 highlighted that due to physics, it was expected the technology would consistently gather around a tenth to a hundredth of the power of solar energy.

"However, it does provide us with some electricity while we're asleep, and we generally consume electricity while awake," he added.

Future prospects for the technology
The team drew inspiration for creating "night-time" solar energy mainly from technologies utilised in top-tier 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.

Currently, the new device is solely operational within a laboratory setting.

 

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