Australian researchers developed a technology that uses night-time solar to generate electricity.
“When we use photovoltaic solar cells to collect sunlight [during the day], we have only been exploiting half of the opportunity,” says project leader Ned Ekins-Daukes.
Then why has this breakthrough been so unlikely?
Professor Ekins-Daukes says solar energy is still available long after the sun sets and the day gets dark.
“The sun is the source of our energy – it arrives on Earth, heats it, but the Earth sends back exactly the same amount of energy back to space”, he says.
“As energy is transferred from the Earth to the universe, thermal emissions are released.”
There is “a large and unused spectrum of potential power to be exploited” if Professor Ekins-Daukes and his team can tap into this radiant heat and convert it into electricity.
A study published in ACS Photonics developed a technique for capturing and converting infrared photons into electricity by using a thermo radiative diode (an existing semiconductor sensor used in technologies like night-vision goggles).
As Professor Ekins-Daukes puts it, “you’re interrupting that flow of radiant heat that escapes into the universe every night, and you’re capturing a little electricity from it.”
According to him, the technology enables the generation of energy from the cold, starry night sky, which is a very promising prospect.
What does it mean?
Solar power is one of the most popular forms of energy in Australia. In the past decade, more than 3 million people have installed solar panels. Moreover, Australian households installed rooftop solar systems at a record pace of more than 3,000MW in 2021.
The newest “night-time solar” technology is very much in its infancy according to Professor Ekins-Daukes.
In the beginning, we are able to make a device that consumes very little energy, but that is to be expected when you’re at the very early stages of development,” Professor Ekins-Daukes says.
Approximately 1/100,000th of the energy of a solar cell was produced.
They argue, however, that it is the “proof of concept” that matters.
It will depend greatly on how involved industrial partners are in the development and manufacturing of the Thermo radiative diode, Professor Ekins-Daukes tells PhysOrg.com. “And by engaging industry, we get a chance to lower costs,” he says.
In addition to finding new materials, it will take some time to achieve [widespread use].”
In the future, however, combining photovoltaics, or solar panels, and Thermo radiative diodes could be possible for “night-time solar” power.
It would be possible to use a panel to generate power during the day, but you could also use it to run other devices in your house at night.”