I'm an EE by schooling and I've worked in both gas turbine and wind power. Photovoltaics blow my fucking mind. Everything else is just spinning magnets to extract power. PVs are insanely cool
Yeah, it's a super rad tech! A bit pricey but a neat renewable that almost generates opposite to solar in a way, in that if it's raining you're getting some energy in the form of fresh water
Can you ELI10 an intuitive explanation on why the salinity gradient provides energy? It doesn't make intuitive sense to me and never has. Like why is fresh water mixing with salt water energy positive?
It doesn't. It's the thermal energy that is converted to electricity.
The salinity gradient provides an entropy dump. The dialysis machine is built in a way that the only possible way for that entropy to increase is by generating some electricity.
when you dissolve salt in water, then salt splits into ions and each can hold up specific number of water molecules, which means that this water can't do water things. so on top of salt's physical presence, there's a fraction of water that can't water, or salt water is less watery in a sense than fresh water. now it turns out, if you put a membrane between these two that allows water through but not salt, water goes to higher salinity on its own, because it's less watery there. how hard it happens is quantified as osmotic pressure and it can be in tens of atmospheres. reverse electrodialysis is just a clever arrangement that avoids energy recovery from low volume of high pressure liquid, like how reverse of reverse osmosis would work
I actually don't know why people get so hung up on this. When you are making energy it's easiest to make heat, and boiling water through a turbine is a really efficient way to turn heat into motion and we're really good at doing it and turning motion into electricity. The fact that multiple ways of making heat exist is not surprising, the fact that different methods of making heat use the same, most efficient, well understood method for turning heat into electricity is even less surprising.
If we develop a more efficient way to turn heat into electricity it won't be "a new way to make energy" it will be "a new more efficient heat engine"
We also have developed solar panels, wind turbines, hydro-electric dams as well as tidal/wave energy devices in the intervening years - so adding another method to boil water just feels “outdated”.
I’m not trying to cast judgement myself, just trying to explain that it feels like it’s just “vibes based”.
Take a look at a modern supercritical steam turbine, this thing can run on 600C steam. there's nothing archaic about it (it can be more efficient as a part of combined cycle)
I had an idea for a dumb Star Trek meme, based on the episode where they explain how Romulan warp drives work, but extrapolating that to "it boils water and spins a turbine". Maybe one of the Star Trek memers can take this and run with it?
No, wind is spinning magnets. Everything except photovoltaics and fuel cells is spinning magnets. (Everything with boiling water is also spinning magnets)
There's peltier devices, too, which use heat traveling via different metals and maybe some sort of sorcery to generate a voltage.
Also teslacoils use a different mechanism (friction I believe), though that's a static voltage.
In theory, you could translate a magnet through a coil instead of just rotating it to produce a current. Lol spinning a ring magnet through a rounded coil could be a different way of using spinning magnets (assuming it isn't already done).
yeah but its waaay less efficient than a turbine. the only reason to use internal combustion is because its cheaper and better able to handle variable rotation rates. grid scale power generation will always favor efficiency over initial cost, at least to a point, and a generator is preferred to spin at one speed anyway.
66 Comments
ininewcrow@lemmy.ca · 85 pts · 81d
The idea .....
Send water on a 150 million kilometer pipeline to the sun to super heat it ... then pipe the steam back to power a turbine
nightwatch_admin@lemmy.world · 48 pts · 81d
Baby Dyson Sphere go brrr
lime@feddit.nu · 57 pts · 81d
dyson tube
Skullgrid@lemmy.world · 16 pts · 81d
I don't know why you made me laugh so much, thanks for that post.
I think it's because it turns the concept into something so low tech and banal
lime@feddit.nu · 14 pts · 81d
right? like a potato gun for space
BonsaiBoo@lemmy.world · 12 pts · 81d
You just described every rocket ever made by man.
lime@feddit.nu · 4 pts · 81d
potato guns are not typically self-propelled. i'm thinking more like HARP
diabetic_porcupine@lemmy.world · 3 pts · 81d
There could be a whole industry of Dyson Dudes that run back and forth with the tubes
aeronmelon@lemmy.world · 12 pts · 81d
Dyson Straw.
tempest@lemmy.ca · 18 pts · 81d
What if the pipeline already existed... But it was made of light
JoShmoe@ani.social · 13 pts · 81d
Shut up science
danekrae@lemmy.world · 9 pts · 81d
Clent@lemmy.dbzer0.com · 5 pts · 81d
Wouldn't even need to run it out that far and we don't have the material science to handle temperatures near the sun.
applebusch@lemmy.blahaj.zone · 3 pts · 81d
this is just the inverse of concentrated solar. you bring the pipe closer to the light rather than bringing the light closer to the pipe.
ininewcrow@lemmy.ca · 5 pts · 80d
You're not invited to the team building the Solar Dyson Tube Project
_stranger_@lemmy.world · 1 pts · 80d
new idea, we bring the sun closer to the Earth, run everything on boiling rock.
myotheraccount@lemmy.world · 2 pts · 81d
The pipe can double as a space elevator
FauxPseudo@lemmy.world · 55 pts · 81d
Nuclear power is just steampunk with magic rocks.
4am@lemmy.zip · 26 pts · 81d
Spicy rocks
Lost_My_Mind@lemmy.world · 10 pts · 81d
Too spicy for Ukraine, circa 1986.
ThrowawayPermanente@sh.itjust.works · 6 pts · 81d
3.6M Scoville. Not great, not terrible
aeronmelon@lemmy.world · 4 pts · 81d
So spicy they make everything around them spicy.
frank@sopuli.xyz · 38 pts · 81d
I'm an EE by schooling and I've worked in both gas turbine and wind power. Photovoltaics blow my fucking mind. Everything else is just spinning magnets to extract power. PVs are insanely cool
marcos@lemmy.world · 16 pts · 81d
Take a look at reverse electro-dialysis.
It's pushing thermal energy into electricity directly by the force of entropy.
bitjunkie@lemmy.world · 9 pts · 81d
The what now
marcos@lemmy.world · 7 pts · 81d
Entropy is maximized by turning heat into electricity, so electricity appears on the device, as it gets cooler (by a tiny amount).
EDIT: I just noticed that you may be asking about the "reverse electro-dialysis" part :)
It's a process where fresh and salty water enter a machine, and they get mixed while generating electricity. It's the reverse of this:
https://en.wikipedia.org/wiki/Electrodialysis
That runs on the same conceptual machine.
(And oh, looks like it's written together.)
frank@sopuli.xyz · 2 pts · 81d
Yeah, it's a super rad tech! A bit pricey but a neat renewable that almost generates opposite to solar in a way, in that if it's raining you're getting some energy in the form of fresh water
Can you ELI10 an intuitive explanation on why the salinity gradient provides energy? It doesn't make intuitive sense to me and never has. Like why is fresh water mixing with salt water energy positive?
marcos@lemmy.world · 3 pts · 81d
It doesn't. It's the thermal energy that is converted to electricity.
The salinity gradient provides an entropy dump. The dialysis machine is built in a way that the only possible way for that entropy to increase is by generating some electricity.
rain_enjoyer@sopuli.xyz · 1 pts · 81d
when you dissolve salt in water, then salt splits into ions and each can hold up specific number of water molecules, which means that this water can't do water things. so on top of salt's physical presence, there's a fraction of water that can't water, or salt water is less watery in a sense than fresh water. now it turns out, if you put a membrane between these two that allows water through but not salt, water goes to higher salinity on its own, because it's less watery there. how hard it happens is quantified as osmotic pressure and it can be in tens of atmospheres. reverse electrodialysis is just a clever arrangement that avoids energy recovery from low volume of high pressure liquid, like how reverse of reverse osmosis would work
Lost_My_Mind@lemmy.world · 7 pts · 81d
Your name makes me think you're about to lather your own naked body in vasoline, and hide inside the couch.
frank@sopuli.xyz · 5 pts · 81d
I'm known to lather a bit, as a treat.
Rooskie91@discuss.online · 6 pts · 81d
Personally, I like the mirror plants that use the suns energy to superheat salt.
And then use that to boil water. /s
For real, what China is doing with PVs is pretty fucking cool.
kerrigan778@lemmy.blahaj.zone · 36 pts · 81d
I actually don't know why people get so hung up on this. When you are making energy it's easiest to make heat, and boiling water through a turbine is a really efficient way to turn heat into motion and we're really good at doing it and turning motion into electricity. The fact that multiple ways of making heat exist is not surprising, the fact that different methods of making heat use the same, most efficient, well understood method for turning heat into electricity is even less surprising.
If we develop a more efficient way to turn heat into electricity it won't be "a new way to make energy" it will be "a new more efficient heat engine"
thatKamGuy@sh.itjust.works · 6 pts · 81d
Because it feels archaic and inefficient, maybe?
We also have developed solar panels, wind turbines, hydro-electric dams as well as tidal/wave energy devices in the intervening years - so adding another method to boil water just feels “outdated”.
I’m not trying to cast judgement myself, just trying to explain that it feels like it’s just “vibes based”.
rain_enjoyer@sopuli.xyz · 13 pts · 81d
Take a look at a modern supercritical steam turbine, this thing can run on 600C steam. there's nothing archaic about it (it can be more efficient as a part of combined cycle)
Hydropower and windmills are older than steam
swab148@lemmy.dbzer0.com · 8 pts · 81d
I had an idea for a dumb Star Trek meme, based on the episode where they explain how Romulan warp drives work, but extrapolating that to "it boils water and spins a turbine". Maybe one of the Star Trek memers can take this and run with it?
Tiral@lemmy.world · 2 pts · 80d
You mean black holes as a power source?
Will technically in Balance of Terror in ToS they were using fusion drives still. They vented excess plasma and wraponized it.
swab148@lemmy.dbzer0.com · 2 pts · 80d
Yeah, the black hole one. Like, they use the heat generated by the black hole to boil water, spin thingy. Super dumb, could be funny!
vithigar@lemmy.ca · 7 pts · 80d
Three of your four examples are already outputting mechanical energy of motion so don't need the intervening conversion step provided by steam.
ChickenLadyLovesLife@lemmy.world · -1 pts · 80d
ch00f@lemmy.world · 4 pts · 80d
The problem is there’s an upper limit on how much useful energy you can extract from a heat engine.
1 - Tc/Th
The only 100% efficient heat exchanger has a cold side at absolute zero.
rumba@lemmy.zip · 3 pts · 80d
AND that can maintain absolute Zero on that cold side. Getting heat to leave into the void at those temps is a battle
Proprietary_Blend@lemmy.world · 21 pts · 81d
Where wind
Klox@lemmy.world · 18 pts · 81d
Step 1: boil the ocean
aeronmelon@lemmy.world · 2 pts · 81d
Isn’t that what unchecked capitalism is already doing?
danekrae@lemmy.world · 10 pts · 81d
Boiling water, obviously!
5ibelius9insterberg@feddit.org · 20 pts · 81d
No, wind is spinning magnets. Everything except photovoltaics and fuel cells is spinning magnets. (Everything with boiling water is also spinning magnets)
bumblefumble@mander.xyz · 4 pts · 81d
You could always spin some wire and let the magnets stay still if you wanna be different.
5ibelius9insterberg@feddit.org · 2 pts · 81d
Well… if a wire moves in a magnetic field, a current is induced. If a current runs through a wire, it generates an electromagnetic field.
So in this case: spinning wire = spinning magnet
gnutrino@programming.dev · 3 pts · 81d
Also primary battery cells.
Buddahriffic@lemmy.world · 3 pts · 81d
There's peltier devices, too, which use heat traveling via different metals and maybe some sort of sorcery to generate a voltage.
Also teslacoils use a different mechanism (friction I believe), though that's a static voltage.
In theory, you could translate a magnet through a coil instead of just rotating it to produce a current. Lol spinning a ring magnet through a rounded coil could be a different way of using spinning magnets (assuming it isn't already done).
5ibelius9insterberg@feddit.org · 2 pts · 81d
And wise-ass got outwiseassed. Chapeau
PS: you forgot to mention piezoelectricity
autriyo@feddit.org · 3 pts · 81d
We're kinda just using magnets to push around other magnets remotely.
And then there's other stuff attached to those magnets.
Skullgrid@lemmy.world · 7 pts · 81d
It's also due to water being boiled. Just in a different, many steps removed manner.
pennomi@lemmy.world · 14 pts · 81d
chaogomu@lemmy.world · 5 pts · 81d
Those systems are interesting, but also nightmares to build and maintain.
Supercritical co2 is a powerful solvent and can corrode most metals.this problem is worse when you increase the temperature.
Material scientists are working on it, but so far, the few test systems that have been built can't quite live up to the hype.
samus12345@sh.itjust.works · 12 pts · 81d
"I have an idea for a comic!"
"Is it you getting angry and sulking on the couch?"
cornshark@lemmy.world · 9 pts · 81d
What's the original comic?
rob_t_firefly@lemmy.world · 12 pts · 80d
Source: Pervis Comics by Zach M. Stafford
Return_of_Chippy@lemmy.world · 8 pts · 81d
Boil water and spin magnets
Zwiebel@feddit.org · 2 pts · 81d
Lorents force go wheeeee
ThePyroPython@lemmy.world · 8 pts · 81d
Well when you invent a new way to convert rotational energy into multi-phase AC please let us all know
Goodeye8@piefed.social · 2 pts · 81d
Explosions?
ThePyroPython@lemmy.world · 1 pts · 81d
Fuck I forgot about internal combustion...
applebusch@lemmy.blahaj.zone · 1 pts · 81d
yeah but its waaay less efficient than a turbine. the only reason to use internal combustion is because its cheaper and better able to handle variable rotation rates. grid scale power generation will always favor efficiency over initial cost, at least to a point, and a generator is preferred to spin at one speed anyway.
SubArcticTundra@lemmy.ml · 7 pts · 81d
Skullgrid@lemmy.world · 4 pts · 81d
Turbine go vrrrrrr
snugglesthefalse@sh.itjust.works · 1 pts · 81d
Can't wait for fusion and magnetic hydrogen.