It’s the end of all sources or energy

In 2022, researchers at the University of New South Wales made a breakthrough in solar electricity generation with a panel that’s capable of operating at night. The concept of a solar power system that works without sunlight may sound impossible, but the technology draws on heat that’s radiated as infrared light after the sun has gone down. Their most recent advancements involve taking the tech to space, and the implications for renewable power are vast.

Australian university team develops nighttime solar power system

Two years ago in 2022, a UNSW (University of New South Wales) team of researchers and scientists revealed that they figured out how to harvest renewable solar power at night, and the technology is being prepared to be dispatched in space. The electricity is produced from the heat radiated into space as infrared light, which is the way the Earth cools after the sun sets.

When looking through a thermal imaging camera, areas of red, white, and yellow can be seen, which indicate the fields of heat from daytime sunlight that is radiating back into space in the form of infrared light. A semiconductor device composed of materials found in night-vision goggles called a thermoradiative diode was used to generate power from the emission of infrared light.

A challenge arose in that the amount of power capable of being generated was small at 100,000 times less than supplied by a standard sunlight solar panel, but according to UNSW team leader Professor Ned Ekins-Daukes, it was an “unambiguous demonstration of electrical power.”

The team’s findings confirm a previously theoretical process, which is an exciting development in the field. Since then, the team has started working on a new material that’s easier to manufacture.

Another technological innovation is being applied in space involving beaming solar power to Earth via a laser for the first time, and the implications for harnessing energy are exciting.

How is the technology going to be used in space?

The new infrared solar technology is being prepared for use in space. The position of the International Space Station, which is an area of low Earth orbit, experiences a day that lasts 90 minutes of half daylight and half darkness. Spacecraft in this area of space need to be powered by solar cells during the day but batteries at night. The new technology is going to make it possible to generate power for the spacecraft to be able to function in darkness.

Professor Ekins-Daukes said:

“The first silicon solar cells were demonstrated in 1953 and by 1958 they were used on the first solar powered satellite. We now generate very large quantities of electricity from solar power for our homes using silicon solar cells, that technology which was first used in space. In a similar way, we intend to fly the thermoradiative diode in space within the next 2 years.”

How does the system work according to thermoradiative principles?

The new technology out of UNSW works on the principle of thermoradiative power generation. This system capitalizes on the temperature difference between the surface of the Earth and the coldness of space. All objects, including the Earth, emit infrared radiation.

The new technology involves capturing this outgoing radiation and converting it into electricity. The integral component of this system is a semiconductor specifically designed to capture this radiant heat energy in the form of infrared light. This then generates an electrical current.

Professor Ned Ekins-Daukes explained:

“What we did was we made a semiconductor device [that] takes advantage of that radiant heat that’s leaving the Earth, and as that light is emitted, it generates some electricity.”

Inspiration was drawn from night vision goggles

The research team explained that the semiconductor device is a kind of thermoradiative diode that uses materials similar to those found in night-vision goggles.

Dr Phoebe Pearce, one of the researchers on the project, offered more information:

“In the same way that a solar cell can generate electricity by absorbing sunlight emitted from a very hot sun, the thermoradiative diode generates electricity by emitting infrared light into a colder environment. In both cases, the temperature difference is what lets us generate electricity.”

Another innovation in the world of solar power systems that’s making waves is renewable energy company First Solar has revealed what it describes as the “world’s first” bifacial solar panel.