Solar Energy? At Night Time? Aussie Researchers Say It’s More Likely Than You Think

Solar Energy? At Night Time? Aussie Researchers Say It’s More Likely Than You Think
Image: Zhengzaishuru on iStock

Researchers at the University of New South Wales (UNSW) have produced ‘night-time’ solar energy. You know, solar energy when the sun isn’t shining.

That… Is kind of remarkable, and could disarm one of the major criticisms of solar energy, being that it can’t produce energy at all hours, given that solar panels rely on the sun to generate electricity.

A team of researchers from the UNSW School of Photovoltaic and Renewable Energy Engineering were able to create electricity from infrared light, using the energy that radiates off of the Earth at night. They’ve been working on this research for a while, and have now successfully pulled it off. The research is similar to that which we’ve previously seen in the area, but this is the first time we’ve seen it successfully create energy.

“We have made an unambiguous demonstration of electrical power from a thermoradiative diode,” said associate professor Ned Ekins-Daukes, the team leader of the project.

“Using thermal imaging cameras you can see how much radiation there is at night, but just in the infrared rather than the visible wavelengths. What we have done is make a device that can generate electrical power from the emission of infrared thermal radiation.

“Down the line, this technology could potentially harvest that energy and remove the need for batteries in certain devices – or help to recharge them. That isn’t something where conventional solar power would necessarily be a viable option.”

night time solar
Infrared energy is everywhere. Image: UNSW

The thermoradiative diode was instrumental to this process, created specifically for this experiment with materials similar to what you can find in night-vision goggles.

In the most basic terms, as the Earth emits infrared energy (which it builds up during the day and emits back into space at night), the diode is able to use the emission of energy to generate power.

The amount of power that was generated with this test was quite small, said to be about 100,000 times less than what is typically supplied by a solar panel. That being said, you got to start somewhere, right? It’s still rad as (Get it? Cause infrared radiation? Ah, you get it).

Ekins-Daukes added that the original theory for this technology indicated that it could, ideally, produce one tenth of the power of a solar cell. Additionally, he said that progress on the technology could be sped up if industries got involved.

While technically it’s a bit different from typical solar power generation, it’s still generating electricity from a solar energy source. The infrared energy that remains ambient on the Earth is still perfectly useable and harnessable, if a more powerful form of this experiment were to be created.

“Photovoltaics, the direct conversion of sunlight into electricity, is an artificial process that humans have developed in order to convert the solar energy into power. In that sense the thermoradiative process is similar; we are diverting energy flowing in the infrared from a warm Earth into the cold universe,” added Dr Phoebe Pearce, a co-author of the paper.

“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. In both cases the temperature difference is what lets us generate electricity.”

This is a pretty exciting breakthrough, to be honest. If we could produce solar energy at night time then it could be another renewable innovation.

The research has been published in ACS Photonics.