Australian researchers have created a device that can produce power from heat radiation using a similar mechanism to night-vision goggles.
Following a significant advancement in thermal capture technology, the sun’s immense energy may soon be captured even in the dead of night. During the day, solar radiation greatly warms the earth’s crust, but when the sun sets, that heat is lost into the icy depths of space.
Researchers from the University of New South Wales’s School of Photovoltaic and Renewable Energy Engineering have now successfully tested a device that can convert infrared heat into electrical power. The team, which included individuals from the ARC Centre of Excellence in Exciton Science, used a power-generation tool called a “thermo-radiative diode,” which is comparable to the technology found in night-vision goggles. The study was published in ACS Photonics on May 9th.
Exciton Science Associate Investigator Nicholas Ekins-Daukes, the leader of the research team, said: “In the late 18th and early 19th century it was discovered that the efficiency of steam engines depended on the temperature difference across the engine, and the field of thermodynamics was born.
“The same principles apply to solar power – the sun provides the hot source and a relatively cool solar panel on the Earth’s surface provides a cold absorber. This allows electricity to be produced. However, when we think about the infrared emission from the Earth into outer space, it is now the Earth that is the comparatively warm body, with the vast void of space being extremely cold. ”
“By the same principles of thermodynamics, it is possible to generate electricity from this temperature difference too: the emission of infrared light into space.”
Norwegian researcher Rune Strandberg first explored the theoretical possibility of such a device, and researchers at Stanford University are investigating alternative approaches to capturing thermal energy at night.
The amount of energy produced through this new test is small (roughly equivalent to 0.001% of a solar cell), but the proof of concept is significant.
“We usually think of the emission of light as something that consumes power, but in the mid-infrared, where we are all glowing with radiant energy, we have shown that it is possible to extract electrical power,” Nicholas said.
“We do not yet have the miracle material that will make the thermoradiative diode an everyday reality, but we made a proof of principle and are eager to see how much we can improve on this result in the coming years.”
The team is now excited to move to the next research phase in creating and refining their own devices to harness the power of the night, and welcome potential industry partners.
Reference: “Thermoradiative Power Conversion from HgCdTe Photodiodes and Their Current-Voltage Characteristics” by Michael P. Nielsen, Andreas Pusch, Muhammad H. Sazzad, Phoebe M. Pearce, Peter J. Reece and Nicholas J. Ekins-Daukes, 9 May 2022, ACS Photonics.