Electricity from the air sounds too good to be true. But researchers have announced this week they have found a way of harvesting electricity from the thin air. Of course its not coming literally from the air but rather from the electromagnetic radiation passing through it.
This while not exactly a waste material is certainly partly going to waste. We are talking about radio waves mainly. Signals from Wifi and other radio signals. What researchers have done is come up with new materials that can harvest the signals and convert it to a small amount of power. There is nothing new in this and your radio or Wifi works on the same principle using Farady’s theories of electromagnetism . The radio signal is converted to small amounts of electricity which an amplifier uses to convert to sound (in the case of a domestic radio). Some mobile phones can be charged without plugging them in (although by a bespoke electromagnetic beam) and there is talk of charging electric cars in the same way. What’s new is the material can harvest the power and are flexible. One sort of harvester is a sort of table cloth.
Whilst electricity from the air looks interesting it suffers from a couple of drawbacks. The amounts of power are very low and come from conventional electricity sources before they hit the air. It not a free lunch. Presumably the amounts of power you are removing do not interfere with signal quality. It raises some issues you could harvest your neighbours Wifi power in fact in most cases there would be little way of telling where it has come from. But if you think about your Wifi radiates in every direction and most of the time most of its going to waste.