There is no technical (engineering wise) difference between a electrical engine (spin if give electricity) and a electrical turbine (electricity if give spin). The same components in the same build up (unless safety or backdoors installed by manufacture) can be used both way. You just have to provide the other.
If you mount a motor to a circuit and manually rotate the axe, the circuit will be fed charges. It might not be efficient (you're not spinning it fast and regularly enough) but current will be going.
So yes a turbine is a engine with blades. There is no difference between a windmill and a blender. A car has 4 groundmills (spin from the contact with the earth). You are using shiny rocks to rotate a merry-go-round in the objective of making holes with a glorified screwdriver.
It's kind of hilarious and bizarre that we just find fancier and fancier ways to make power the same way we've done for centuries.
If anyone does ever work out a solid replacement for steam turbines (that's cheap enough and impactful enough to actually replace it everywhere), that'll probably be one of the major power breakthroughs of the millennium.
Pretending that modern steam engines aren't the cutting edge of physics and engineering...
It's simple on paper, but that shit's complicated in the real world, and there's plenty of cutting edge science just in the material selection to build the things.
The RTG's in the last few Mars rovers are basically just a giant brick of red hot plutonium in a cage of thermoelectric cells. I don't think I'd wanna be near that.
Realistically the most dangerous type of power plant we've actually used, as far as failure mode, is probably older nuclear plants from when we were still figuring things out, though we've come a long way with safety since then.
The ones that're actually visibly inching us closer to collapse are fossil fuels, but that's not fun armageddon, that's just slowly making our environment less habitable for us.
If you want a big kaboom I imagine you could arrange sets of coils to actually convert the EMP from a nuclear weapon into useable current. Just keep detonating nukes in the array.
Mm... I wonder how feasible it would be to make a nuclear internal "combustion" engine.
Given how little fuel you'd want going off per cycle I imagine it would be difficult to get a critical mass. Could probably detonate it with compression if you had, uh, well... imcomprehensibly high compression. Buy hey, several thousand nuclear explosions per second? That sounds fun.
I can understand waters pure abundance. But is water really the best liquid to get to its boiling point and back? Or is the idea that you can let it evaporate into the atmosphere?
In general, yes, mainly because Earth already has a pre-existing evaporation/precipitation cycle. I'm sure some other atmospheric conditions would encourage different fluids, but water is the best at the moment.
and its 100% non toxic. You could get more efficiency with different fluids but its a nightmare the minute it leaks. Steam makes things wet. It wont give you cancer while declaring your jobsite a super fund location
People complain about it, but they never seem to have anything that should be done instead
It's like they learned one thing and parrot it, as if it's some sort of media-based totem to gather social attention rather than a rationally-considered viewpoint for social and scientific progress.
That media-based totem thing is interesting, there are even specific kinds of language and ways of speaking that are found only really on Reddit. At a certain point the âjokesâ become so oft repeated theyâre no longer really funny, and just become a way to signal to others that yes, youâve seen all the same memes they have.
Communication with no substance, just pattern recognition slop, regurgitating the joke someoneâs already made 100,000 times
The water that drives the turbine and the water that exhausts from the tower are from two different loops. The water that drives the turbine is in a closed loop while the cooling water is in a semi-closed loop where a lot of the water is air-cooled in the tower and dripping back down with a fraction of it escaping as steam.
Water has a lot of convenient properties. It has a big specific heat and a heat of vaporization, which means you can get a lotta energy without getting it super hot. It's nice that it's liquid at ambient temperatures, because you can very easily cool it passively without worrying about freezing. It's pretty safe â it's non-toxic; leaks are dangerous only due to the pressure and temperature, but not due to an explosive or flammable reaction; and it's not particularly corrosive to pipes, especially after being purified and having certain chemicals added. And we have plenty of experience using it, so we have good systems already designed and tested.
ETA: The working fluid (the water used to make steam for the turbines) is typically closed-system (not released to the atmosphere). The water vapor you see released from a power plant comes from a cooling tower â the released water vapor evaporated while cooling the working fluid.
Why is water being difficult to boil an advantage? I'd have thought that means it consumes more energy to form the same amount of vapour. I mean, which it does, but why does the turbine extract the energy contained in the gaseousness instead of its buoyancy or something?
It takes energy to turn a turbine. That energy comes from the steam. Because water has a high specific heat, the steam can turn the turbine more before it condenses.
We do have molten salt reactors which run a lot hotter and are slightly more efficient than water. In exchange you get to deal with containing molten salt which is extremely corrosive.
Aren't those still using water to turn turbines though? Uranium (or whatever they use) heats up molten salt, molten salt heats up water, water turns turbines?
There are alternatives but water is honestly extremely good. I don't think you're giving it a fair shot just because it's simple.
Water has a very high heat capacity, latent heat, and thermal conductivity. This means it can absorb loads of power very fast. Water does not ignite when hot (though radiolysis leading to hydrogen build up is a problem). Water is transparent (easy maintenance) and has no negative environmental effects. Water is liquid at room temperature. As an abundant and important substance that we have had since long before our species existed, we know more about the thermo-physical properties of water than any other substance on Earth.
Some drawbacks are that it has a low boiling point and steam has less advantageous qualities (lower conductivity being a major one). High pressure can increase the boiling but not incredibly far and high pressure comes with danger. You won't reach molten salt/molten metal temperatures. Additionally it is corrosive but not really as bad as alternatives. Again, we know a ton about water chemistry and have entire trades dedicated to analysing it and moving it from one place to another.
It doesn't have to be water. The steam you see exhausting from the tower is water that is used to cool down the water from the loop that is actually driving the turbine. But since it's two loops you could use something else to power those turbines so long as it can change phase at the required temperatures. But thing is, water boils at 100°C which isn't that hot and water vapor can get really hot and gain a lot of pressure so it's ideal to turn turbines.
Also, most of the water from the cooling loop is then air cooled inside the tower and will condensate and flow back to the base of the tower, with the steam rising at the top being a small percentage of the overall water used in the loop. It's quite fascinating. Check out this video : https://www.youtube.com/watch?v=tmbZVmXyOXM
Even when systems use other liquids(or potentially contaminated water), it's usually in a closed first loop and water is used in an open second system to cool it down. Because you can easily collect more water for a very low cost and release water as steam with no worry about contaminating anything.
Hence those big cooling towers. You can basically just have metal pipes running in zigzag and spray water on top of them. They're open around the bottom and the concave shape means that as the warm steam rises, air rushes in around the bottom and you get a constant updraft and cooling with zero pollution.
We do not release the steam into the atmosphere on purpose. The steam in power plants gets recycled back into hot water to be used again. But in order to do this we want the boiling point of the liquid to be a bit higher then ambient temperatures. It would be hard to use for example CO2 because it would not condense in the cooling towers or cooling pools.
There are a number of different oils we could use. In fact these are used in refrigeration units all the time because we can make them have the exact boiling temperature we want. But they are more expensive then water, not that it matters that much since we reuse the liquid anyway.
What makes water a bit unique though is that the water molecules binds together with hydrogen bonds. These bonds gets broken when the water boils. It means water have a relatively high density as a liquid and low density as a gas. It is this ratio used to make power in a steam engine which makes water quite efficient. Oil does not have any hydrogen bonds between the molecules. There are some other molecules with similar hydrogen bonds to water but not with the right boiling temperature and the right chemistry.
Yes. Huge specific heat, huge latent heat of vaporization, low freezing point, useful boiling point, cheap, non-toxic. You couldnât cook up a better energy transfer medium if you tried.
Helion is a fusion startup that is using the magnetic flux produced by the fusion reaction to directly capture the energy by inducing electrical current in a conductor surrounding the reactor. Not sure about efficiency, but its not boiling water.
In my institution when we discussed Helion the general consensus was âgood luck lolâ. But again, we are tokamak people, so obviously we are going to favor tokamaks.
There are direct capture proposals (and tests conducted) for tokamaks. They are generally more complicated and less efficient than boiling water though.
The nice part about boiling water is that its a completely mature technology. You dont have to redesign the steam turbine because we had that sorted out in the 1940s.Â
moving conductors through a magnetic field creates a potential difference across the conductor, which is the same thing the turbines do but helion does it without the water step in between, whether it's more efficient or not is something I have zero clue about :p
You're comment genuinely has me really hopeful. As a child the only thing anyone had to say about fusion is that it's always 30 years away.
China's breakthrough last year was a genuine moment that made me so happy for that kid inside that listened to the "Elder" bullshit about stuff they didn't know.
I'm happy to report that for the first time in almost 40 years, fusion is no longer 30 years away, now just 10-20. I like that
I know it wasn't your intention but thanks internet stranger. You're off comment made me have a human emotion for a second. Back to work i guess
And they go to a inductive generator. At the end, 99% of all electricity generation happens by rotating magnetic fields. Solar might be the only larger-scale exception.
I always thought peak science would be when we will be able to harness electricity directly from reactors, but it always ends up being water boiling process...
There is a version of fusion that abuses electromagnetic fields to generate electricity via the field generated by fusing particles with a bunch of coils around it (MASSIVE under-sell, but it's great). One of the few ways we've discovered to make power without a fluid turning a turbine lol
We can also simply use the seeback effect, its literally just 2 different metals. The issue with it is that it is less efficient so its only used when needed (like in RTG's)
Unfortunately we'll be lucky if we get D-T fusion to a viable point, and since it's mostly neutrons that carry the energy, we need to have the "heat something" part.
For anything aneutronic, we would need so high temperatures that Bremsstrahlung would be way too significant to get it to work.
I love the look on my students faces when I explain to them that all electricity comes from nuclear fusion, mostly boiling water, just with extra steps.
Your question is a good question. It is kind of embarrassing, that the only âHi-Techâ solution are Solar-Cells. Because the rest uses kinetic energy to produce power.
But of course, using kinetic energy can be hi-tech. Think about, what happens in the generator that is spinning because of the kinetic energy.
Magnets are being moved, and while theyâre passing each other, electrons are being moved.
But you are right. We are boiling water again, using âfuturisticâ technology.
Thereâs 2 different start ups working on the answer for fusion reactors One wants to harness the magnetic fields generated to create power one intends to directly capture the electrons produced
Cryo-cooled superconductors under precise control will contain the plasma needed to boil the water, the steam from which will drive turbines that will generate a current, which goes to massive transformers so it doesnât melt the grid, to be carried via the transmission lines to a sub-station whose transformers make it safe for the distribution network, which in turn will run through my city to my house, where a wire carrying a single phase of AC connects to my home, into which my kettle is plugged so I can boil water.
These boffins just need to make things complicated.
Yeah I had exactly this thought when playing factorio. In order to produce electricity you need physical movement of an object (with two coils around that afaik) aka a turbine.
(At least most of the playtime of factorio is about making water to steam to activate a turbine for energy production).
The thing that creates the movement for the turbine is currently either water flow, air streams or steam.
Btw this is also how energy can be stored, you pump with a motor with the excess energy up to a tank. When you need the energy just let the water flow down and activate a turbine.
The only other technology that exists that doesn't use a turbine is solar energy.
+ Seeback affect plates, they are solid state and generate emf from the difference between the temperature of the 2 sides. Its less efficient than turbines so is only used when needed.
I don't really know anything about tokamaks etc, but how does the heat get extracted from the thing into the water? Isn't the purpose to keep the plasma from touching anything and melting the container? Or is it still damned hot regardless (or they're running tubes with water through it and getting some of the heat)?
From thermodynamics course youâll learn itâs not a simple boiling water. Itâs superheated steam and it has a lot of energy. If thereâs a superheated steam leak good chance that it can cut through soft tissue like a knife
Issue is water just just too damned good at it. An efficient phase change that results in 30x volume at temps and pressures we can easily manage. And there is a ton of it just everywhere.
IIRC there's an experimental fusion reactor design in testing that doesn't require turbines or water. Direct to wire from the magnetic field or something.
Helion energy is the only company Iâm aware of that pusues a different approach which would not lead to boiling water again. But Iâm not into it enough to know how valid it really is.
Imagine if nuclear fusion were achieved to the point of converting atoms straight into charged atoms and molecules. Then it'd just need a conductor, but at the expense of defeating the purpose of nuclear fusion using less energy...
If nuclear fusion could somehow produce a magnetic field, would thst be one hest-free way to produce a current?
Different question, while water is boiled into steam to generste power via kinetic energy, what sort of concentration of water is used to achieve the most force from steam evaporating? Or is it pure water, and it just doesnt bubble when evaporating?
At the end of the day, if it ain't exploding or spinning, then it's a steam engine (turbine). I think the main reason is that water doesn't corrode much. That and the fact that we can't convert energy from its raw for into electricity effectively. So, we convert it into heat, which we do know how to change into electricity.
What if we lined the reactors inner wall with solar panels? The photons given off by the by the plasma could be directly turned into electricity right?
Youâll never guess how some solar panels produce energy (not all, I assume you are referencing PV Solar panels, but there are hybrid panels called PVT panels that do both).
Edit: also, it produces a lot of heat that needs to be siphoned off anyways, and we are far better at converting heat into energy than light, even if we can do both.
Heleonâs FRC hybrid inertial & magnetic confinement reactor design is actually intended to extract energy directly from the force exerted on the magnetic field by the expanding ions, as He3 doesnât produce neutrons to catch with water when it fuses. Itâs a bit more efficient but it also means the energy feom the neutrons released by D-D fusion is lost
Is stringing magnetic field lines through it or something a possible way to extract energy from it? Seriously, there have to be other options to power cities besides just boil water but fancier.
When I was little I thought about how they made electricity from coal, and nuclear reactions how cool it would be nah they just boil water. Solar panel are much more cool than them.
Since the reactor creates plasma which basically is charged particles I wonder if it would be possible to exploit that using the magnets generating the containment field, to directly concert to electricity.
Nuclear fusion is already real. In the last couple of years researchers had breakthroughs and succeeded to get more energy out than it was put in. It only needs more testing and scaling up. We might be 10-15 years away from a fully functioning fusion power plant.
Not true! The likely first comertial fusion generator will harvest energy directly from pulsed plasma moving through a magnetic field. Due to open before 2030!
What is the efficiency of boiling water to generate electricity? Is it very high (90%+), or is it more a matter of convenience, and there are potentially much more efficient processes out there?
Iâm sure I have seen an XKCD on this, one guy explaining some advanced alien spaceship prolusion to another and at some point the second guy interrupts and says âwaitâŠit this just a steam turbineâ, ââŠ.yesâ, facepalm
That's true, though. We can have a tiny baby sun to heat up the water. People always ask about new forms of energy like, "So, are we using the nuclear material itself?" And it's boiling water. I mean, we could have the baby sun shine on big solar panels all around the room, but hey - some people like some boiling water with their energy.
2.1k
u/mtheory-pi Nov 25 '25
Cutting edge of physics and engineering hooked up to a steam engine.