Australian scientists discover a way to capture solar energy at night

Australian scientists discover a way to capture solar energy at night

By Laura Chalk  May 26th, 2022

You’d be forgiven for thinking that solar energy can only be captured during the day when the sun is out. However, a breakthrough discovery is proving this may not be the only opportunity.


A group of researchers from the School of Photovoltaic and Renewable Energy Engineering at the University of New South Wales has recently found it’s possible to conduct infrared radiation on its way out of Earth at night, rather than just during the day on its way in. This has the potential to significantly increase the overall amount of energy that we can harness from the sun once technology develops enough to exhaust daytime supply.

Here’s how it works (in layman’s terms): heat, a form of energy, travels from hot to cold areas. Every day, the earth absorbs heat from the sun. At night, this heat leaves the earth in the form of infrared light and is sucked out into the freezing ether of space. This process is needed for Earth to maintain a temperature cool enough to support life.

UNSW scientists use a ‘thermoradiative diode’ - a type of semiconductor also used in night vision goggles - to capture the infrared radiation as it leaves earth. This radiation is then converted into electricity.

“The flow of energy from hot to cold zones is how solar energy works,” Ned Ekins-Daukes, the teams’ lead researcher said in a media release.

“The solar panels are cool whereas the sun beaming on them is hot. At night, the earth becomes the source of heat and the icy temperature of space is the cold absorber.

“By the same principles of thermodynamics, it is possible to generate electricity from this temperature difference too: the emission of infrared light into space.”

The amount of power generated by ‘night solar’ remains very small – around 100,000 times less than that supplied by a standard solar panel. However, the researchers believe with enough investment, the technology could one day generate around 10 per cent of the power produced by a solar powered cell. 

“This could mean being able to achieve the ultimate dream of renewable energy: power generation uninterrupted by the setting of the sun,” the researchers claim.

The team also believe the technology could have a range of other uses in the future by helping to produce electricity in new and innovative way, for example powering bionic devices (such as artificial hearts) via body heat.

Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.


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Laura Chalk

With a background in Teaching English as a Second Language and Communications, Laura joined Planet Ark in 2016. Laura has a passion for the environment and behaviour change, and is excited about using social media to help people take positive environmental actions everyday.

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