The sun’s enormous energy could soon be harnessed in the dark of night thanks to a significant advance in thermal capture technology.
Solar radiation significantly heats the earth’s crust during the day, but this energy is lost in the coldness of space when the sun goes down.
Now researchers from the School of Photovoltaic and Renewable Energy Engineering at UNSW Sydney have successfully tested a device that can convert infrared heat into electrical energy.
The team, including members of the ARC Center of Excellence in Excitation Science, used a power-generating device called a “thermo-radiative diode”, which is similar to technology in night vision goggles.
Exciton Science associate researcher Nicholas Ekins-Daukes, the leader of the research team, said: “In the late 18th and early 19th centuries it was discovered that the efficiency of steam engines depended from the temperature difference across the engine and from 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 helps generate electricity.
“However, when we think of Earth’s infrared emission in outer space, it is now Earth that is the relatively hot body, with the vast vacuum of space being extremely cold.
“By the same principles of thermodynamics, it is also possible to generate electricity from this temperature difference: 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 by 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 light emission as something that consumes energy, but in the mid-infrared, where we all glow with radiant energy, we have shown that it is possible to extract electric power,” Nicholas said.
“We don’t yet have the miracle material that will make the thermoradiative diode an everyday reality, but we’ve done a proof-of-principle and are excited to see how much we can improve on that outcome in the years to come.”
The team is now excited to move on to the next phase of research by creating and perfecting their own devices to harness the power of the night and welcome potential industry partners.