Atmospheric moisture as a promising source of renewable energy
Due to climate change, not only scientists, but also politicians are concerned about the study of renewable energy sources. In addition to the development of solar panels, wind turbines, hydroelectric dams and geothermal wells, researchers are also looking for new promising sources. In recent years, there have been developments related to the generation of energy through atmospheric moisture..
Energy from the air
Water has many special properties, including the transfer of electric charge when molecules collide with each other and the creation of a kind of static electricity due to their friction.
We have all observed powerful bursts of energy during a thunderstorm in the form of lightning, which are formed only due to water in its different phases. The cloud formation process clearly demonstrates how, in about 20 minutes, atmospheric moisture and raindrops can generate huge electrical discharges of several kilometers..
Harnessing the energy released in this way is very difficult, and capturing it would require the installation of a huge number of rods with the appropriate infrastructure. The efficiency and productivity of such systems would depend only on the whims of nature..
However, back in the 19th century, English physicist Michael Faraday discovered that water droplets can also charge metal surfaces as a result of friction between them. What’s more, recent research has shown that some metals spontaneously build up an electrical charge when exposed to moisture..
We are accustomed to the fact that static electricity occurs in dry air, for example, when a doorknob is shocked. Water is usually considered a good conductor, not something that can build up a charge on the surface. However, things change when the relative humidity exceeds a certain threshold, according to the researchers..
In the course of experiments, scientists from Tel Aviv University found that in dry air conditions, the voltage between two metal surfaces (one of which is grounded) is completely absent, but when the humidity level rises above 60%, a potential difference arises between the insulated metals. They observed this in the laboratory and in the natural environment..
Subsequent measurements showed that moist air can serve as a source of charging surfaces to a voltage of about one volt. In comparison, current small AA batteries have a nominal voltage of 1.2 V to 1.6 V. So scientists have already begun to develop special batteries that can be charged by moisture in the air..
In the long term, the development of this technology can lead to an expansion of the list of renewable energy sources used by mankind. However, such systems will work most effectively in regions with a tropical climate..
A team of researchers from the University of Massachusetts Amherst recently unveiled their own development related to the extraction of energy from atmospheric moisture. Their device is an air generator with electrically conductive protein nanowires, which does not need special environmental conditions, can work around the clock and even indoors. Scientists named their system Air-gen.
The main element of the generator is a thin film less than 10 microns thick, located between two electrodes. In this case, the upper electrode only partially covers its surface..
The principle of operation of the device is based on the fact that the film adsorbs water vapor from the atmosphere, and then, due to the chemical composition and surface structure, generates an electric current between two electrodes..
The existing prototype can only power small electronics, but it can function even in the desert. In the future, the development team plans to create large-scale systems for industrial needs.
text: Ilya Bauer, photo: ccacoalition, Shutterstock