No, really, it is:
Harvesting electricity from the air
Dr Yao said: “What we realised after making the Geobacter discovery is the ability to generate electricity from the air – what we then called the ‘Air-gen effect’ – turns out to be generic.
“Literally any kind of material can harvest electricity from air – as long as it has a certain property.
“It just needs to have holes smaller than 100 nm (nanometers) – or less than a thousandth of the width of a human hair.”
This is because of a parameter known as the “mean free path” – the distance a single molecule of water travels in air before it bumps into another.
The researchers found they could design an electricity harvester based around this number made from a thin layer of material filled with nanopores smaller than 100nm.
They would let water molecules pass from the upper to the lower part of the material.
Each pore is so small they would easily bump into the edge as they pass through – meaning the upper part would be bombarded with many more charge-carrying water molecules than the lower.
It creates a charge imbalance, like those found in a cloud, as the upper part increased its charge relative to the lower part, creating a battery.
And now the question not answered here. How much? Sure, a cloud can produce lightning and that’s a lot. But clouds are also pretty big. So, how much usable power can we get here? Inswhatever it is we use to measure power, watts, amps, grannies or stones?