Droplet Based Electricity Generator

Though this may be possible, it doesn't sound practical....at all....

Note the word "instantaneous". "Instantaneous power density" without duty cycle information is not very informative when you are talking about a power source. I would like to see average power or efficiency in converting the kinetic energy of the falling drops into electrical energy.

https://scitechdaily.com/new-droplet-based-electricity-generator-a-drop-of-water-can-light-up-100-led-bulbs/

Doesn't appear to be capable of sustained output as the source of the electricity is an electret that must replenish it's charge between discharges...

...."There have been numerous attempt to generate electricity using rain, but this may be one of the more effective solutions yet. Researchers have developed a generator that uses a field-effect transistor-style structure to instantly produce a surprisingly high voltage from water drops -- a single drop can muster 140V, or enough power to briefly light up 100 small LED bulbs. Earlier generators without the structure produced "thousands" of times less instant power density, the scientists said.

The new design mates an aluminum electrode with an indium tin oxide electrode layered with PTFE, a material with a "quasi-permanent" electric charge. When a drop hits the PTFE/tin surface, it bridges the two electrodes and creates a closed-loop circuit. That helps fully release any stored charges. The technology could handle sustained rainfall, too. If there are continuous drops, the charge accumulates and eventually hits a saturation point.

There's still work to be done to translate this to a practical product. A brief burst of energy is easy -- accumulating enough of it for continuous power is another matter. "...

https://www.engadget.com/2020/02/09/raindrop-electricity-generator/

...."An electret can be considered a piece of dielectric material with the presence of quasi-permanent real charges on the surface or in the bulk of the material, or frozen-in aligned dipoles in the bulk. An electret behaves like a battery or acts as an electrical counterpart of a permanent magnet. A piece of poled ferroelectric material can also be an electret. The term quasi-permanent implies that the amount of charges stored in the material does not remain the same permanently, but decays very slowly depending on the situation, and the decay time is normally much longer than the time period over which the electret is in use."....

..."Some electrets can be formed by applying a mechanical pressure to the dielectric material. In this case, surface charges can be acquired simply by contact electrification, deformation, or friction without the application of an electric field.12"...

https://www.sciencedirect.com/topics/materials-science/electrets

All I need to know is, supposing there is too much rain, will the rain generate enough to run a pump?

One might argue that this is a snowflake based generator.

To me, this doesn't pass the smell test. A FET does have an extremely high input impedance and therefore very little of a load on what it is sensing. A FET does not convert one form of energy into another, a transducer like a microphone does that. A FET allows a transducer to modulate another power source without taking much power from the transducer. I know the article says this is FET-like and not an FET but this is one of the fundamental attributes of a FET. It, therefore, should approximate this attribute of an FET.

I'm with you, I don't see how this is "FET-like", other than it is a capacitor, like the gate of an insulated gate FET.

This is the way I'm thinking it works:

The PTFE is an electret, a dielectric with a permanent electric field frozen in, analogous to a permanent magnet. For the sake of argument, assume the top is positive and the bottom negative.

To generate energy, the drop has to move against the electric field force, losing kinetic energy. When the drop lands on top of the PTFE, it contacts the aluminum electrode which is connected to the bottom (negative) side of the PTFE. The drop is now negatively charged and attracted to the positively charged surface of the PTFE. As it falls, it's kinetic energy is transferred to the electric field, increasing its intensity.

It's the same principle as a Van de Graff generator where moving a charged belt against an electric field generates energy.

I like the idea that the PTFE electret property of a permanent electric field can be the root of this but doesn't that just make this an electret microphone? As the link shows, these have been known for a century. They're also available to hobbyists for under $2, in bulk I expect them to be even cheaper.

I understand the cheap electret mics don't have much voltage.

https://www.physicsforums.com/threads/buying-or-making-an-electret.309926/

You can make an electret with a high voltage power supply (e.g. old TV HVPS) and an oven.

http://onetuberadio.com/2019/03/20/how-to-make-an-electret/

Here is some more information for making your own:

https://rimstar.org/materials/electrets/

You would think that good electrets for experiments would be available from scientific supply companies, but that doesn't seem to be the case.

So someone has worked out how falling rain generates lightning and comes up with possible uses. I am thinking this should be included with the magnetic arm bracelets.

Maybe they should experiment with sandblasting where quite large charges can build up while bead blasting.

Then they could put electrodes int volcanic ash blasts which also generate lightning.

The power required to pump the water to generate the droplets or "rain" will doubtless be less than is produced.
Naturally occurring rain probably isn't predictable enough.
Del

Maybe you only need electricity when it rains, like lighting up a "slippery when wet" sign...

Well, the idea is great, but the realization needs some upgrade as this could not work well enough. Creating the alternative source of electricity is the number 1 question in the world for now, but it won't last long, i think we are close enough to invent something that will change our world once and forever. We need to do that or we will pay the bills till the last day of our lives. I am paying nearly 300$ for my electricity plan and this is awful. I think this is a robbery and I need to do something with that. As long as I can't have another source of energy I will have to pay, but I want to pay less, and that's why I was looking for another electricity supplier and I found it. It was really easy to perform the change, I had to sign the document and that's all, this service made it all. Now I will pay less, a lot less than I used to pay. Maybe those guys are using the drop system for the energy generation as the prices are very low

This is the first time I've seen information about such a generator. I'm not saying it's an innovative solution, but still.