Device for generating electricity at night from infrared radiation

The device from the University of New South Wales team uses special semiconductors to collect infrared radiation emitted by the Earth and convert it into electricity.

The idea of ​​generating electricity after the sun sets may seem impossible, but a team at the University of New South Wales has developed new technology to achieve this, Interesting Engineering reported on September 28. They have just tested the device on Earth and are planning to evaluate its feasibility in space. Their technology works on the principle of thermal radiation power generation . The process exploits the temperature difference between the Earth's surface and the coldness of space.

The team took infrared images of Sydney Harbour at night to show the amount of radiation at night. (Photo: University of New South Wales).

All objects, including the Earth, emit infrared radiation . The newly developed device collects this emitted radiation and converts it into electricity. The key part of the device is a semiconductor, which is specially designed to take advantage of this radiant heat. When the Earth emits infrared light, the semiconductor collects the energy and generates an electric current. By converting radiant heat into electricity , the device can essentially generate solar power at night, according to lead researcher Ned Ekins-Daukes.

The semiconductor is a type of thermal radiation diode, the researchers say . The material used to make the device is similar to night vision devices. "In the same way that photovoltaics generate electricity by absorbing light from the Sun, thermal radiation diodes generate electricity by emitting infrared light into a colder environment ," explains Dr. Phoebe Pearce, a member of the research team. " In both cases, the temperature difference is what allows us to generate electricity."

The efficiency of the new technology is currently quite low, but the team is optimistic about future improvements. The output is 100,000 times less than a photovoltaic cell, but it is proof of the feasibility of the device, according to Professor Ekins-Daukes. The team predicts that their technology will have a wide range of applications beyond the limits of current energy sources, such as harnessing body heat to generate electricity.

On a larger scale, Ekins-Daukes and his colleagues are looking to adapt the technology for use on spacecraft. Satellites in low Earth orbit are often shadowed, relying on batteries while in the dark. The thermal radiation diode offers a potential solution for generating electricity even when there is no sunlight. The team plans to launch the thermal radiation diode into space within the next two years. The breakthrough could pave the way for a future where renewable energy is available 24/7.