It’s possible, researchers are now showing

When the sun goes down, the solar panels are turned on. But this can sometimes change.

Solar panels are on the rise; More and more surfaces are covered with it. But those panels have a major drawback; They are only able to generate energy during the day. But there is hope. The researchers showed that it is also possible to generate solar energy at night. Not based on sunlight, but based on solar heat radiated by the Earth.

the heat
“All warm objects emit infrared radiation,” researcher Ned Akins explains. Scientias. nl From. “If you point a thermal camera at a person, you can see that person glow, because his or her body is much warmer than the surrounding space. In a similar way, the Earth radiates all the energy it receives from the sun back into space in the infrared.” Ekins and his colleagues have now used that energy to generate electricity.

dual vacume
They use what’s called a thermal diode, which is made from materials you also find in night vision goggles. “A thermal diode is a semiconductor device that can transmit a portion of that radiant energy. Just as a solar cell intercepts the flow of energy from the sun to Earth, a thermal radiant diode intercepts the energy flow from Earth as it radiates into space.” Ekins asserts that this flow of energy comes indirectly from the sun. Sunlight has previously reached Earth and heated it, then this heat is sent back into space by Earth in the form of infrared radiation.

With a diode, a portion of the infrared light can be absorbed and then converted into electricity. “Just as a solar cell can generate electricity by absorbing sunlight emitted from very warm sunlight, a thermodynamic diode generates electricity by delivering infrared light to a cooler environment,” explains researcher Phoebe Pearce. “Either way, the difference in temperatures is what allows us to generate electricity.”

temperature difference
“So the device generates electricity by emitting light,” Ekins added. “It is important to note that we can always generate power if there is a temperature difference. This temperature difference is between the Sun (very hot) and Earth (warm), but also between Earth (warm) and space (very cold). In the case of cells Solar, we have the hot sun and a cold solar cell. But the same effect can be used – with the help of other materials – to generate electricity when the source gives off heat to a cold environment.”

small return
However, the amount of electricity generated using a thermal radiant diode is nowhere near the yield of conventional solar panels. In fact, the amount of energy the researchers can generate at this point with a TRT diode is at least 100,000 times smaller than that from solar panels. But Ekins believes the return could be increased dramatically. “Currently we can generate a very small amount of electricity with a TRD,” says Ekins. “One of the challenges of our research was to discover the electricity generated. But theory dictates that it should eventually be possible to save about one-tenth of the energy generated by solar cells.”

interconnected group
With such a limited yield, thermo-radiative diodes are far from able to compete with conventional solar panels. However, they can be used in addition to solar electrodes. Ultimately, the technologies can be combined with the thermal radiant element behind the solar cell. And for a household, the radiant thermostat should be able to generate enough power in the dark to power devices that also work at night – like freezer, WiFi router, etc. “

body temperature
But there are more possibilities. For example, our body heat can also become a source of energy in a similar way. “Wherever there is a temperature difference, we can generate a thermal radiant current,” says Ekins. “If you take a thermal photo of me, I will glow brightly in the infrared light because I’m around 37 degrees Celsius and my environment is 20 degrees Celsius.” And this temperature difference can be used, for example, to power a smartwatch. “If we scale a current TRD to the size of a watch, the diode can generate enough power based on body heat to power such a watch. And who knows, in the future we may also develop semiconductors that can be incorporated into clothing. In that case, it would be It is possible to generate energy from the infrared rays emitted by our clothing.”

There is work to be done
It’s the music of the future right now. After all, some work still needs to be done to convert the thermal radiative diode that the researchers are now using as part of their research project proof of concept To move to more efficient devices that can harness solar power at night on a much larger scale. Ekins and his colleagues remain cautiously optimistic that this technology will make a difference in the future. “The radiant diode can help by providing power at sunset,” says Ekins.

However, in the future, a major role will be reserved for the business community. We believe we can increase revenue by a factor of 10,000. Once the technology reaches the stage where companies can make money selling the product, we expect the industry to pick up the idea and start helping to scale up costs and bring down costs.” And then it can go fast.” If the industry sees value With that, we can move forward very quickly.”