- While generating solar power after the sun has set may seem impractical, researchers at the University of New South Wales have found a way to accomplish it.
- The newly developed device captures this outgoing radiation and converts it into electricity.
While generating solar power after the sun has set may seem impractical, researchers at the University of New South Wales have found a way to accomplish it. They have developed a new technology that could soon be powering our homes at night. Notably, the researchers have already tested this device on Earth and plan to assess its usability in space as well.
Their technology works on the principle of thermo-radiative power generation. This process capitalises on the temperature difference between the Earth’s surface and the coldness of space. For reference, all objects, including the Earth, emit infrared radiation.
The newly developed device captures this outgoing radiation and converts it into electricity. Its key component is a semiconductor, which has been specifically designed to exploit this radiant heat.
As the Earth emits infrared light, the semiconductor captures this energy and generates an electrical current. By capturing and converting this radiant heat into electricity, the device generates “solar power at night.”
“What we did was we made a semiconductor device … it takes advantage of that radiant heat that’s leaving the Earth, and as that light is emitted, it generates some electricity,” team lead Ned Ekins-Daukes said.
According to a press release by the researchers, the semiconductor device was a type of thermo-radiative diode. Interestingly, the materials used to create this device were similar to those found in night-vision goggles.
“In the same way that a solar cell can generate electricity by absorbing sunlight emitted from a very hot sun, the thermo-radiative diode generates electricity by emitting infrared light into a colder environment,” explains Dr Phoebe Pearce, one of the researchers on the project. “In both cases, the temperature difference lets us generate electricity.”
The efficiency of this new technology is currently low, but the research team is optimistic about future improvements. The amount of power was small, 100,000 times less than that supplied by a solar panel. Still, it was an ‘unambiguous demonstration of electrical power,’ said Professor Ekins-Daukes in the press release.
The research team anticipates that this new technology will have a wide range of applications, going beyond the limitations of current energy sources. Professor Ekins-Daukes even suggests the possibility of harnessing body heat to generate power.
“Down the line, this technology could potentially harvest that energy and remove the need for batteries in certain devices – or help to recharge them. That isn’t something where conventional solar power would necessarily be a viable option,” he remarked.
On a larger scale, the team is actively working on adapting the technology for use in spacecraft. Satellites in low Earth orbit experience frequent eclipses, relying on batteries during periods of darkness. The thermo-radiative diode offers a potential solution, generating power even without sunlight.
“We now generate vast quantities of electricity from solar power for our homes using silicon solar cells, the technology first used in space. Similarly, we intend to fly the thermo-radiative diode in space within the next two years,” concluded Prof. Ekins-Daukes.