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This is an article written by someone who has no idea what they're talking about: > Until now, previous attempts to convert evaporation energy into electricity

This is an article written by someone who has no idea what they're talking about: > Until now, previous attempts to convert evaporation energy into electricity have suffered from a low-conversion efficiency. But using the drinking bird method, scientists have managed to generate an output of 100 volts using just 100 millilitrers of water, enough to power small electronic devices. I would take it with a huge grain of salt.

zackkatz 3y ago
Agreed. This article makes it sound like this is a perpetual motion machine.
- BobaFloutist 3y ago
  The laws of thermodynamics apply in closed systems, and our planet is not a closed system. Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes. Heat pumps kind of violate the "you can't get something for nothing" principle too, since you can get >100% return on the electricity you put into them. The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us. There's no thermodynamic reason you couldn't have a small device on your desk that uses ambient heat, moisture, light, etc to store energy that you can use to do work, just engineering and chemical reasons it's hard to do this on a scale that's relevant. https://en.wikipedia.org/wiki/Crookes_radiometer https://en.wikipedia.org/wiki/Crookes_radiometer is over 100 years old and, if kept in sunlight, can provide "perpetual motion" for "free".
  - thaumasiotes 3y ago
    > The laws of thermodynamics apply in closed systems, and our planet is not a closed system. > Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes. I get solar power and hydro [also solar] power, but isn't geothermal power a closed part of the system? Where does solar input feature in that? > The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us. This is also a closed part of the system. If the argument you're making is "the planet is not a closed system", then you need to be using energy that comes from outside, not energy that is already contained in the system.
    - BobaFloutist 3y ago
      The sun is arguably ultimately responsible for geothermal. Even if geothermal is part of the closed system, it's still functionally perpetual motion for our purposes. The main argument I'm making is that perpetual motion* is, for all practical purposes, possible, as long as you're willing to be specific, and you're unconcerned with the heat death of the universe (none of us should be concerned with the heat death of the universe).
recursive 3y ago
Among whatever other problems there are here, volts are not a measure of energy or power. The units don't make sense.
- bilsbie 3y ago
  Plus the water isn’t an input/consumable.
- mrguyorama 3y ago
  At least that confusion is a "normal" one in terms of pop-literature talking about energy. Every "new" energy scam talks about the voltage gradient generated as if it is meaningful, with zero information about the state of the circuit generating that voltage. I will never understand how insanely ignorant the average person is about electricity when every single electrical object in the US comes with label that concisely and accurately describes how much voltage and current it uses, and you get billed by the kWh, and the equation that pulls all this together is literally a simple multiplication, and I've struggled to put two transistors together in a circuit every single time I've tried to learn analog electronics! It feels like watching that early internet video of the lady that couldn't figure out that if you are driving 60 mph, you drive one mile a minute. I want to be clear, I'm saying this as someone who struggles with doing basic dimensional analysis in high school physics. I cannot comprehend the willful and purposeful ignorance that most people seem to carry throughout their lives. I don't think people do enough recreational math or unit conversions. My STEM trained friend recently expressed surprised at how much chicken "2 kg" is, and I just don't get it. 1 pound is close enough to 500 grams as to not care about the actual conversion! Same as 1 meter = 1 yard, and 1 qt damn near equals 1 liter. I know my brain is broken compared to most, but how do you live without figuring these things out?
  - deleted 3y ago
    [deleted]
  - williamcotton 3y ago
    2.2 lbs to kg. 39 inches to the meter. 3.79 liters to 4 quarts. 1.6 km to the mile. * 9/5 and + 32 for C to F. I think those are correct? I think I was made to memorize those at some point, but of note, I am also an immigrant to the US from a wacky metric system nation.
gertrunde 3y ago
For me it was this line: > In the natural world, evaporation occurs when sunlight warms the surface of the Earth, breaking the bonds which hold water molecules together. Which is... sort of not inaccurate, but feels like it implies a misleading concept, and makes me think the author copied it without understanding it.
- thaumasiotes 3y ago
  > Which is... sort of not inaccurate Really? Do puddles not dry up at night? My impression was that evaporation occurs because that's just the way liquid behaves. It's more important that water molecules are really small than that they experience sunlight. Temperature-based evaporation is "boiling", and sunlight doesn't make a meaningful difference there, as far as water goes...?
  - Turing_Machine 3y ago
    The phrase "breaking the bonds which hold water molecules together" can be interpreted two different ways. 1) Breaking the covalent bonds that hold individual water molecules together, preventing them from splitting into two hydrogen and one oxygen atom. That's clearly not true. 2) Breaking the hydrogen bonds that stick one water molecule to another, keeping the water in liquid form. That's true. In any case, it's poorly phrased.
    - thaumasiotes 3y ago
      Is that right? Molecules with no polarity can still form liquids. It happens all the time; we call those liquids "hydrophobic" (or, most commonly, we call them "oils"). The hydrogen bonds aren't what's keeping the water in liquid form. Cooking oil, notably, will not evaporate the way water will -- if you spill it somewhere, the oil will mostly just stay wherever you left it until you clean it up -- but my understanding was that this is because oil molecules are huge and heavy while water molecules are tiny.
      - thedanbob 3y ago
Turing_Machine 3y ago
Right. I can generate an output of tens of thousands of volts by scuffing my feet on the carpet, but I won't be replacing Hoover Dam any time soon.
sonicanatidae 3y ago
The size of the salt "grain" required would crush any mortal man/woman/LargeAnimal and leave a 100m wide, 50m deep, divot in the ground.
quickthrowman 3y ago
> This is an article written by someone who has no idea what they're talking about: Agreed, ‘output of 100 volts’ is meaningless without knowing the current. Edit: Looks like it puts out 3.6 microwatts (0.0000036 watts) at 100v, or (assuming single-phase) 0.000000036 VA

zackkatz 3y ago

Agreed. This article makes it sound like this is a perpetual motion machine.

BobaFloutist 3y ago
The laws of thermodynamics apply in closed systems, and our planet is not a closed system. Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes. Heat pumps kind of violate the "you can't get something for nothing" principle too, since you can get >100% return on the electricity you put into them. The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us. There's no thermodynamic reason you couldn't have a small device on your desk that uses ambient heat, moisture, light, etc to store energy that you can use to do work, just engineering and chemical reasons it's hard to do this on a scale that's relevant. https://en.wikipedia.org/wiki/Crookes_radiometer https://en.wikipedia.org/wiki/Crookes_radiometer is over 100 years old and, if kept in sunlight, can provide "perpetual motion" for "free".
- thaumasiotes 3y ago
  > The laws of thermodynamics apply in closed systems, and our planet is not a closed system. > Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes. I get solar power and hydro [also solar] power, but isn't geothermal power a closed part of the system? Where does solar input feature in that? > The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us. This is also a closed part of the system. If the argument you're making is "the planet is not a closed system", then you need to be using energy that comes from outside, not energy that is already contained in the system.
  - BobaFloutist 3y ago
    The sun is arguably ultimately responsible for geothermal. Even if geothermal is part of the closed system, it's still functionally perpetual motion for our purposes. The main argument I'm making is that perpetual motion* is, for all practical purposes, possible, as long as you're willing to be specific, and you're unconcerned with the heat death of the universe (none of us should be concerned with the heat death of the universe).

recursive 3y ago

Among whatever other problems there are here, volts are not a measure of energy or power. The units don't make sense.

bilsbie 3y ago
Plus the water isn’t an input/consumable.
mrguyorama 3y ago
At least that confusion is a "normal" one in terms of pop-literature talking about energy. Every "new" energy scam talks about the voltage gradient generated as if it is meaningful, with zero information about the state of the circuit generating that voltage. I will never understand how insanely ignorant the average person is about electricity when every single electrical object in the US comes with label that concisely and accurately describes how much voltage and current it uses, and you get billed by the kWh, and the equation that pulls all this together is literally a simple multiplication, and I've struggled to put two transistors together in a circuit every single time I've tried to learn analog electronics! It feels like watching that early internet video of the lady that couldn't figure out that if you are driving 60 mph, you drive one mile a minute. I want to be clear, I'm saying this as someone who struggles with doing basic dimensional analysis in high school physics. I cannot comprehend the willful and purposeful ignorance that most people seem to carry throughout their lives. I don't think people do enough recreational math or unit conversions. My STEM trained friend recently expressed surprised at how much chicken "2 kg" is, and I just don't get it. 1 pound is close enough to 500 grams as to not care about the actual conversion! Same as 1 meter = 1 yard, and 1 qt damn near equals 1 liter. I know my brain is broken compared to most, but how do you live without figuring these things out?
- deleted 3y ago
  [deleted]
- williamcotton 3y ago
  2.2 lbs to kg. 39 inches to the meter. 3.79 liters to 4 quarts. 1.6 km to the mile. * 9/5 and + 32 for C to F. I think those are correct? I think I was made to memorize those at some point, but of note, I am also an immigrant to the US from a wacky metric system nation.

gertrunde 3y ago

For me it was this line: > In the natural world, evaporation occurs when sunlight warms the surface of the Earth, breaking the bonds which hold water molecules together. Which is... sort of not inaccurate, but feels like it implies a misleading concept, and makes me think the author copied it without understanding it.

thaumasiotes 3y ago
> Which is... sort of not inaccurate Really? Do puddles not dry up at night? My impression was that evaporation occurs because that's just the way liquid behaves. It's more important that water molecules are really small than that they experience sunlight. Temperature-based evaporation is "boiling", and sunlight doesn't make a meaningful difference there, as far as water goes...?
- Turing_Machine 3y ago
  The phrase "breaking the bonds which hold water molecules together" can be interpreted two different ways. 1) Breaking the covalent bonds that hold individual water molecules together, preventing them from splitting into two hydrogen and one oxygen atom. That's clearly not true. 2) Breaking the hydrogen bonds that stick one water molecule to another, keeping the water in liquid form. That's true. In any case, it's poorly phrased.
  - thaumasiotes 3y ago
    Is that right? Molecules with no polarity can still form liquids. It happens all the time; we call those liquids "hydrophobic" (or, most commonly, we call them "oils"). The hydrogen bonds aren't what's keeping the water in liquid form. Cooking oil, notably, will not evaporate the way water will -- if you spill it somewhere, the oil will mostly just stay wherever you left it until you clean it up -- but my understanding was that this is because oil molecules are huge and heavy while water molecules are tiny.
    - thedanbob 3y ago

Turing_Machine 3y ago

Right. I can generate an output of tens of thousands of volts by scuffing my feet on the carpet, but I won't be replacing Hoover Dam any time soon.

sonicanatidae 3y ago

The size of the salt "grain" required would crush any mortal man/woman/LargeAnimal and leave a 100m wide, 50m deep, divot in the ground.

quickthrowman 3y ago

> This is an article written by someone who has no idea what they're talking about: Agreed, ‘output of 100 volts’ is meaningless without knowing the current. Edit: Looks like it puts out 3.6 microwatts (0.0000036 watts) at 100v, or (assuming single-phase) 0.000000036 VA