Des chercheurs de l’université de Nouvelle-Galles du Sud (Australie) montrent comment une diode thermoradiative peut exploiter le rayonnement infrarouge pour produire de l’électricité. © martinlisner, Adobe Stock

Solar energy can be used in the middle of the night!

Let’s say it right away. The amount of electricity generated is very small. About 100,000 times less than you can expect from a conventional solar module. But the idea is perhaps worth considering in spite of everything. Especially since the Researchers from the University of New South Wales (Australia) hope they can improve the technology. To produceenergy on a much larger scale. This technology is the generation of electricity from a infrared radiation. You know, the one that emanates from every hot body. Including our human body.

What relation tosolar power ? It’s just the day, the white light
The wavelengths of visible light range from about 380 nm (violet) to 780 nm (red). The visible spectrum is…” data-image=”” data-url=”https://” data-more=”Read more”>bright The sun is the closest star to the earth, from which it is about 150 million kilometers away. The Sun is 8.5 kParsecs from the center of the Milky Way. In the stellar classification, the Sun is a G2 type star.
The mass…” data-image=”” data-url=”https://news.” data-more=”Read more”>Sunwarms our earth. In response, it cools at night by emitting radiation Infrared. The use of this infrared radiation to generate electricity is – of course indirectly, but still – the result of taking electricity from our sun in the middle of the night. And all this here with a component that is already in so-called night vision.

“Just as a solar cell can generate electricity by absorbing sunlight emitted during the day, our thermal radiation diode generates electricity from infrared light emitted in a cooler environment at night. In both cases it is the temperature difference that allows us to produce electricity.”says Phoebe Pearce, researcher at the University of New South Wales, in a communicates .

Electrical medical devices

To understand this, we must remember that building materials, intelligent materials, ecological materials…
A…” data-image=”” data-url=” .com/sciences/definitions/physics-material-15914/” data-more=”Read more”>material is heated atoms who make it are excited. Her electronsin addition. The phenomenon is small. To channel that excitation and turn it into a useful flow of electrons, researchers at the University of New South Wales came up with the idea of ​​using a diode. Here a diode from General
Symbol: TeNumber…” data-image=”” data-url=”https://news” data-more=”Read More”>tellurium from Mercuryand general
Symbol: CdAtomic number: 48Electrons per energy level: 2, 8, 18, 18, 2Atomic mass: 112,414 uHighest isotopes…” data-image=” /1/ d/5/1d520fc2da_74202_cadmiumccwiki.jpg” data-url=”” data-more=”Read more”>cadmium . And in their conducted experiments it was shown that such a device is able to take advantage of a temperature difference between the ground and the earthAir of about 12.5°C — a temperature difference typically at night – to generate 2.26 milliwatts of energy per square meter. It seems little.

However, the researchers point out that the first solar cell in the 1950s had an efficiency that did not exceed 2%. Today, the top performers are generating returns of 23%. Following the same model, they hope to rapidly advance their new technology by capitalizing on knowledge already acquired in the field and borrowing materials from the designers of mid-infrared photodetectors. Today it has an efficiency of about … 2%. You intend to successfully reach the 1/10 in the futureand Energy that can be generated by conventional solar cells.

The aim would be to focus on the applicationswho could benefit most from this type of power generation. For example, powering medical devices. Because the human body also radiates in the infrared. So researchers envision their technology could recover that energy and convert it into electricity to power a device invented by John Hopps in 1950
Invention of the pacemaker
After studying engineering at the University of…” data-image=” pacemaker-in-hand-02.jpg” data-url=”” data-more=”Read more”>pacemaker . Typically the type of application that conventional solar energy could not be used for.

Solar panels generating electricity at night

The major disadvantage of solar modules is that they can only produce electricity when the sun is shining. But researchers have envisioned a system that generates power even after dark, a kind of solar cell at night.

Article by Nathalie Mayerpublished on 08/02/2020

Solar panels only produce electricity when the Sun is shining . This is obvious and also one of their weak points. but researcher from the University of California in Davis (USA) now claim to have constructed a type of inverted solar cell that can generate up to 50 wattEnergy per square meter under ideal nighttime conditions. According to them, that is at least a quarter of the daily production capacity of a conventional solar module.

What the researchers are exploiting here is the emission propensity of hot objects in relation to their surroundings Heat in the form of infrared radiation . In this case, they use our earth as a heat source, physicists call heat thermal energy. In the international system, it is therefore measured in joules (J). Heat more closely corresponds to a transfer…” data-image=”” data-url=” https :/ /” data-more=”Read more”>warmthand the night sky as a dissipator. Because space is a particularly cold place. And when you point an object toward the sky, it radiates heat.

A system that can produce 24 hours a day

Thermoradiative cells, on the other hand, generate energy by radiating heat to their surroundings. We usually think of the recovery of waste heat in engines, for example. “We imagined that by placing such a cell in a warm place and pointing it towards the sky, we would get a system that produces energy by giving off heat.”explains Jeremy Munday, a researcher, in a Press release from the University of California at Davis .

According to him, the materials used are different, but the theories established by physics apply within a well-defined framework.
Physics…” data-image=”” data-url=”https:// news” data-more=”Read more”>physicallyis the same as for conventional photovoltaic modules. And then the system could work 24/7 as long as it is protected from the sun during the day. An interesting solution to counteract the intermittent aspect that we thought was inherent in it solar power generation .

The universe, a new source of renewable energy?

By aligning a diode to a semiconductor, unlike a metal, it would insulate at a temperature of zero Kelvin (absolute zero).
Semiconductors are widely used in…” data-url=”” data-more=”Read more”>semiconductorInfrared into the sky, researchers say they will soon be able to generate electricity at night. Everything from a kind of “inverted solar panels” that the temperature differences between the Earth and the The history of the universe begins about 13.7 billion years ago in an extremely dense and hot soup. The laws of physics as we…” data-image=”” data-url=”https : //” data-more=”Read more”>universe .

Article by Nathalie Mayer published on 07/05/2019

New energy source.

“L’vastness of the universeis a resource More generally, thermodynamics deals with the study of energy (especially internal energy) and its…” data-image=” 7/9/f79ceecd52_103843_thermodynamics-refrigerator.jpg” data-url=”” data-more=”Read more”>thermodynamics . » That says Shanhui Fan, researcher at Stanford University (USA). In doing so, he and his team confirm that it is possible to generate a measurable amount of electricity thanks to the cold that prevails in the universe. More precisely, thanks to the temperature difference that exists between our earth and space. A piece of news renewable energy source ?

That photovoltaic solar panels produce electricity from the energy sent from the sun to the earth. The idea of ​​Shanhui Fan and his colleagues: to capture the energy in the form of heat that continuously leaves the surface of our planet with an infrared semiconductor photodiode pointed towards the sky.

A technology in its infancy

To do this, you still need a significant temperature difference. And that’s what the researchers found by pointing their system at space. “But we are far from achieving results that approach the theory’s predictions”tempers another researcher, Masashi Ono.

To give us a concrete idea, they state that they can now generate 64 nanowatts per square meter with such an “inverted solar panel”. Findings that the researchers hope to increase by working on the properties optoelectronicsquanta of their materials. In fact, theory predicts that it should be possible to reach 4 watts per square meter. This remains small compared to solar panels, which generate 100 to 200 watts per square meter.

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