According to an academic study, scientists have developed a cloud device that can generate clean electricity from air humidity. The fingernail-sized Air-gen device is made of a material with holes less than a thousandth the breadth of a human hair. The nanopores generate renewable energy by capturing energy from electrically charged water in the air that passes through them. The technology basically harnesses the power in clouds that causes lightning.
‘Man-made, small-scale cloud’
“The air contains an enormous amount of electricity,” stated Dr Jun Yao of Massachusetts University in the United States. Consider a cloud, which is nothing more than a collection of water droplets.
“Each of those droplets contains a charge, and when the conditions are right, the cloud can produce a lightning bolt – but we don’t know how to capture electricity from lightning in a reliable manner.”
“We’ve created a human-built, small-scale cloud that generates electricity for us predictably and continuously so that we can harvest it.”
The approach may be scaled up for usage in a variety of habitats, including the Amazon rainforest and the Sahara Desert.
There is clean energy everywhere
“Imagine a future world where clean electricity is available everywhere,” Dr. Yao remarked.
“The generic Air-gen effect implies that this future world is a possibility.”
The same scientists demonstrated three years ago how to continually harvest power from the air using a specialist substance made of protein nanowires generated from the bacteria Geobacter sulfurreducens.
“This is very exciting,” said graduate student Xiaomeng Liu, lead author of the latest work, which was published in Advanced Materials. We’re opening up a new avenue for generating clean electricity from thin air.”
They stated that the breakthrough may be leveraged to address the climate crisis by bringing broad commercialization of electric vehicles closer.
“What we realised after making the Geobacter discovery is that the ability to generate electricity from the air – what we then called the ‘Air-gen effect’ – turns out to be generic,” Dr. Yao added.
“As long as it has a certain property, virtually any material can harvest electricity from air.”
“It just needs to have holes smaller than 100 nm (nanometers) – or less than one thousandth the width of a human hair.”
This is due to a parameter known as the “mean free path” – the distance travelled by a single molecule of water in air before colliding with another. The researchers discovered that a thin layer of material filled with nanopores smaller than 100nm might be used to create an electrical harvester based on this number.
New Opportunities
They would allow water molecules to travel from the top to the bottom of the substance. Because each pore is so small, they would easily collide with the edge as they passed through, resulting in the upper half being blasted with many more charge-carrying water molecules than the lower. It causes a charge imbalance, similar to that observed in a cloud, because the top part increased its charge relative to the lower part, resulting in the formation of a battery.
“The idea is simple, but it’s never been discovered before,” Dr. Yao added, “and it opens up all kinds of possibilities.”
