In an experiment, one tube produced 440 microwatts. When the researchers used four tubes at once, they could power 12 LEDs for 20 seconds.

  • kitnaht@lemmy.world
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    4 days ago

    We already use rain to produce lots of electricity, it’s called a hydroelectric dam. I wish people would think before they produced stuff like this.

    • friend_of_satan@lemmy.world
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      4 days ago

      The article is talking about an entirely different way to generate electricity from water

      Normally, when we generate electricity from water, we use the movement of lots of it to drive a turbine in a river, the sea or even in drinking water pipes. But water flowing over an electrically conductive surface can generate its own electrical charge through a process called charge separation. This is driven by positively charged protons of the water molecules staying in the liquid and negatively charged electrons being donated to the surface, much as you can generate static electricity by rubbing a balloon on your hair.

      • kitnaht@lemmy.world
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        4 days ago

        Others have explained why this is inefficient and useless elsewhere in the thread, I suggest looking at those conversations.

        • ilinamorato@lemmy.world
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          4 days ago

          Charge separation is a real thing. It’s the opposite of how an LED works. It’s not very efficient in that direction, but it’s real.

          It works with electrons being excited by photons, though.

          What that has to do with the interface of water and air, I can’t figure out.

          • Aatube@kbin.melroy.orgOP
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            4 days ago

            third paragraph:

            Normally, when we generate electricity from water, we use the movement of lots of it to drive a turbine in a river, the sea or even in drinking water pipes. But water flowing over an electrically conductive surface can generate its own electrical charge through a process called charge separation. This is driven by positively charged protons of the water molecules staying in the liquid and negatively charged electrons being donated to the surface, much as you can generate static electricity by rubbing a balloon on your hair.

            charge separation is a lot more than just photoinduced charge separation

            • ilinamorato@lemmy.world
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              4 days ago

              If that was a real thing, at least in charges strong enough to harness for work, surely we wouldn’t ground sensitive electronics to metal water pipes. And metal fuel containers would be spontaneously exploding all the time. I can’t find any evidence of this phenomenon anywhere but in this article. Can you provide a source?

      • HikingVet@lemmy.ca
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        4 days ago

        Unless you are harnessing a box store, factory or warehouse roof you aren’t going to have the throughput to generate any really useful amount of energy. Also hydro works best where there is constant flow. So sewers would be a better place if you could solve the solids issue.

        • ilinamorato@lemmy.world
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          4 days ago

          box store, factory or warehouse roof

          But isn’t that exactly the sort of implementation we’re talking about here? Especially if you deploy this in large farms around the watershed. One problem with dams is that they have limited potential energy, since you can’t really build a hydroelectric dam in the sky. Harnessing additional kinetic energy for free on its way to the reservoir, capturing energy that otherwise would’ve just gone into the “plop” sound on the dirt, seems like a reasonably good idea; especially if it’s cheap.

          Of course, there’s no way it’s ever going to rival solar or wind (or true hydroelectric). But I hope we learned our lesson long ago to not put all of our energy eggs in one basket.

          EDIT: Nah, you’re right, on a large scale this is unlikely to be able to pay its own manufacturing costs. Perhaps this is more useful as a small-scale energy source.

          • HikingVet@lemmy.ca
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            4 days ago

            This isn’t a terrible idea, and it could be useful as a source of emergency power in places that have high rainfall (paired with a battery system). From my background, I just don’t see it as viable for general use.

              • HikingVet@lemmy.ca
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                4 days ago

                Somewhere that has lots of drop, sure. But hydro relies on head pressure. Which is why most dams are a resevoir with multiple turbines.

        • Bronzebeard@lemm.ee
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          4 days ago

          Yeah but think of how many LEDs you could light for 20 seconds once a week if you spent thousands filling your roof with these!

          • Fermion@feddit.nl
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            4 days ago

            The issue is that it’s a waste of resources. A dam is harnessing energy from the rainfall over hundreds to thousands of square miles of land area. So the resources required to build it, even though large, are very efficiently used over decades of use.

            A tiny system uses orders of magnitude less materials but harvests many orders of magnitude less power. A tiny system probably isn’t going to ever generate more energy than it took to manufacture.

            Systems like this are at best a novelty. We need to all be wary of greenwashed scams, and this is one of them.

            • ilinamorato@lemmy.world
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              4 days ago

              Tiny energy sources have a niche to fill. Think about the minuscule solar panels that power calculators, for instance; that tiny little 0.02W solar cell might be useless for broad-scale deployment, but if you’re instead looking to provide energy to something small and specific in a niche situation, it can be really useful.

              I know this article is talking about deploying this on a house scale, and I even bought into that idea (or, rather, a larger one) in a previous comment; but you’re right, this is unlikely to be a good use of resources.

              Instead, what about deploying this as the power source for a remote meteorological test rig deep in a rainforest? When the rain falls, it gathers energy to make its measurements, stores some in a battery, and transmits its findings.

              Or perhaps deploying it for a small community in a monsoon area which doesn’t rely on much electricity but still needs it for communication in case of emergency. Having a wind, solar, and rain energy collector on it, all feeding a battery, could allow them to have access to emergency services when they otherwise wouldn’t (or when it would otherwise be difficult).

              I’m just saying, energy diversification is a good thing.

      • kitnaht@lemmy.world
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        4 days ago

        Yes and the production of millions of tiny plastic tubes to stick everywhere is a wonderful alternative.