Last month, we wrote a story on solar cells developed by Stanford University that could draw a small amount of power at night, when most would think solar panels would be useless. 

The endeavor to create solar panels that can draw additional power at night is growing. Now, a collaboration of researchers from the School of Photovoltaic and Renewable Energy Engineering at UNSW Sydney and the ARC Center of Excellence in Exciton Science, have developed groundbreaking infrared technology that could lead to nocturnal solar panels. 

The research team ran a successful test on a thermo-radiative diode, a device that converts infrared heat into electricity. It operates on the same technology used in night-vision goggles. 

“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,” Exciton Science associate investigator and lead researcher Nicholas Ekins-Daukes said in a press release. 

“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.”

In initial tests, the amount of energy produced with the thermo-radiative diode was very small compared to daytime solar panel output, about 0.001 percent. While this is a very small start, it does prove that solar panels can in fact produce electricity at night, and the team is conducting more research and creating more partnerships to further the technology.