A team of researchers from Singapore has developed surprisingly simple but revolutionary technology: transform the rain into electricity thanks to a thin plastic tube and a particular flow of water, said Flow Plug.
It looks like a normal hydraulic system, but acts as one Natural battery powered by the rain. To describe it is a study by the National University of Singapore, where the group led by Professor Siowling Soh He has shown how a plastic tube just 32 centimeters long and 2 millimeters wide can generate electricity simply by scrolling inside the drops of water. The secret lies in the way the water moves: not in a continuous flow, but in columns separated by air bagsthus creating the so -called Flow Plug.
In this intermittent flow, each “cap” of water that crosses the internal surface of the tube generates one separation of electric chargesthanks to a phenomenon called contact electrification. It is the same principle that makes a balloon adhere to the hair: when two materials touch each other, they exchange electric charges. In this case, the contact between the water and the internal coating of the tube accumulates opposite charges to the ends. Of the metal wires connected to the base and at the top of the tube they collect this energy, generating electricity.
A functional “rain battery” also on urban roofs and surfaces, without the need for dams or turbines
The device developed by the team requires neither rivers nor waterfalls: gravity and constant rain is enoughlike the one that commonly falls on the roofs. During the tests, the system managed to feed 12 LED bulbs for 20 secondsusing four parallel tubes.
Unlike hydroelectric dams, which require large infrastructure and certain geographical constraints, this system is suitable for urban contexts And it can be integrated on roofs or rainy areas, where traditional renewable sources are not easily installed. According to Soh, the potential is significant: “The rain is abundant and free. We just have to learn to use it better”.
A particularly interesting aspect of this technology is that manages to overcome a historical barrier of electrochemistry. To date, the devices that tried to generate energy by exploiting the contact between liquids and solid surfaces clashed with the limit of the so -called length of debye: an infinitesimal area in which the charges separate, too small to produce useful energy, especially in channels of a diameter of more than 10 micrometers.
The Flow Plug Instead fully bypasses this limitation. The discontinuous flow of water allows the formation of electric charges well beyond the length of Debye, with one energy yield greater than 10% and one power density of about 100 watts per square meter. In practical terms, there is talk of a performance 100,000 times higher Compared to previous systems based on Current streaming.
It is not hydroelectric, it is not sunny: it is triboelectric
This new method is not based on the turbine movement, as happens in traditional hydroelectric systems, nor on sunlight. Instead belongs to the category of triboelectric generatorsdevices that produce energy from friction, bending or, as in this case, from the flow of drops of water.
To date, most triboelectric technologies have had difficulty overcoming the barriers of efficiency and scalability. However, thanks to this minimalist and ingenious solution, The rain could become a new stable source of urban energyable to support other renewable sources.
Real rain could also produce more energy than expected
The researchers tested the system with different types of water: tap water, salted, warm, cold. In all cases, the device worked. But the real surprise comes from the analysis of potential in real life: i natural raindrop fall at a terminal speed higher than the simulated laboratorywhich could further increase energy production.
This discovery could also provide a physical explanation to atmospheric phenomena Like the Lenard effect, responsible for the negative load of the air near waterfalls or marine waves. According to the researchers, even flows with caps, through splashes, splashes and drops would also be spontaneously formed.
Although the prototype is still in the experimental phase, the results are promising. The next step will be to test the duration of the system over timeintegration with existing systems and the resistance to variable weather conditions.
