Ilaria Rosella Pagliaro Scientists at the University of New South Wales have created a system capable of producing energy during the night by exploiting the Earth's heat
©UNSW
In 2022, a team of researchers from the University of New South Wales (UNSW) made a groundbreaking discovery in renewable energy: a system capable of generating electricity even during the night. While it may sound like science fiction, this innovation has become a reality. The system is based on the conversion of Earth’s heat into infrared light, utilizing the temperature difference between the ground and outer space.
After sunset, the Earth lets go of all that heat accumulated in the daytime to the atmosphere in the form of infrared radiation. Such a process can be exploited with the use of thermoradiative diodes, which can capture and transform this energy into electricity. Materials used in these devices are similar to those used in night vision technology; they are designed to absorb heat and transform it into electricity, even at very low light intensities.
According to Dr. Phoebe Pearce, who heads the project,
“A solar panel captures energy from the sun, an extremely hot body. Similarly, a thermoradiative diode uses the infrared light emitted toward a much colder environment, such as space, to generate energy.”
While the system currently only produces electricity at levels up to 100,000 times lower than traditional solar panels, it serves as concrete evidence of a once-impossible process becoming feasible.
Continuous power for satellites and missions
This technology has great promise for application in space. Satellites orbiting the Earth at low Earth orbit experience cycles of 90 minutes of daylight and darkness. When it is daylight, solar panels can provide the power, but at night, satellites rely completely on bulky, expensive batteries.
With thermoradiative diodes, electricity can be generated even during darkness, reducing the dependence on large batteries. Professor Ned Ekins-Daukes, the project leader, highlights the historical significance of this innovation:
“The first silicon solar panels were demonstrated in 1953 and, by 1958, they were powering satellites in space. Today, these panels provide energy for homes worldwide. Our goal is to bring thermoradiative diodes into space within two years.”
This technology could not only enhance the efficiency of space missions but also contribute to their long-term sustainability.
Harnessing human heat: battery-free wearable devices
Beyond space missions, this innovation could revolutionize energy production on Earth. The UNSW team is working on developing new materials to make the diodes more affordable and accessible. This could lead to wearable devices powered by human body heat.
Imagine watches, bracelets, or any other form of wearable having the ability to work without battery. According to Professor Ekins-Daukes,
“This could one day abolish the need to replace batteries in many devices and create devices that automatically recharge themselves.”
Due to such research, solar power is inching toward being a practical answer for night time and even interior conditions by propelling for an era when solar and other alternatives increasingly become relevant sources of power.
A new era for renewable energy
The UNSW researchers’ invention of the thermoradiative diode heralds a new chapter for renewable energy. From powering satellites in space to wearable devices on Earth, the potential applications are endless.
A source of energy hitherto unexploited by humans has now been tapped using infrared light. The innovation promises not only to make space missions more efficient but also offers practical solutions for a world increasingly in need of sustainable alternatives. With advancements like this, the future of clean energy shines brighter than ever.
Source: UNSW
