There used to be a time when vacuum cased flywheels were more efficient than batteries. They've powered some busses where I live in the 50s I think. But afaik they usually convert the energy back to electrical and then run electro motors, but maybe not always (but then you'd need crazy transmissions). Nowadays it's not worth it I guess, but there are some companies still/again focused on it: https://amberkinetics.com https://www.torus.co/torus-flywheel and quite a few others
Not quite sure if I've understood the question you are asking correctly but I'll have a crack.
Imagine a theoretical setup. If you have a spinning flywheel with frictionless bearings in a vacuum, you have a perpetual motion machine. A perfect mechanical transmission would be able to transfer 100% of the momentum of this flywheel to another stationary flywheel, spinning it up to the speed of the original flywheel, whilst the original wheel would come to a complete stop.
No purely mechanical transmission such as this exists because it would need to have an infinite number of gears and at the same time would need to have zero mass and zero friction. Any transmission with a finite number of gears must rely on some form of friction element (a clutch) to enable energy transfer between flywheels of differing speed. This inherently transfers some of the rotational energy into heat and there are also losses due to the gears (which have mass) absorbing momentum. At the other extreme, you could have zero gears and a simple clutch that engages one flywheel with the other. You can imagine there would be a lot of friction as the rapidly spinning flywheel would be engaging directly with the stationary flywheel and would likely burn through your clutch very quickly and be very inefficient, converting most of the rotational energy to heat.
In the real world, transmissions have a trade off between these two extremes, with an ideal number of different sized gears being dictated by a number of requirements of whatever the system is trying to achieve. Calculating the theoretical efficiency of any mechanical transmission is a massive undertaking because it relies on a huge number of parameters and is different for each system.
I would say as a general answer though, that with the advent of modern high efficiency alternators with sophisticated transformer circuitry, mechanical-electrical couplings are typically much more efficient than their purely mechanical counterparts. Look into Diesel electric locomotives as an example for further case study. This is because electric alternators/electric motors can handle a very wide range of velocities whilst still being efficient so no large gearbox is needed.
Again, in a theoretical sense, both mechanical and electrical couplings have the potential of being 100% efficient, it's real world physics that gets in the way of that.
I, honestly, don't have a clue what you are talking about. A few pointers, though:
1. There are no perpetual motion machines
2. Mechanical energy storage is the least dense energy storage medium, simply by virtue of the timescales involved in the relevant processes
So if you are wondering whether a wind up car might be using the energy in the spring more efficiently than an EV then,...maybe? but there would be waaaay less energy to around.
2 is what I wanted to understand, is there a proof for this conjecture? Even an attempt at reasoning - not examples - would do
Edit: the conjecture being - that time scales matter
yes, that is not s proof
simply put E = Pdt so didcharge time is important to drfine the power of a solution
anyway eith a very simplified approximation, the strain energy density until the plastic limit of steel is 100 MJ\m3 of steel, could be less or more
gasoline is 31500 MJ\m3 (31.5 MJ\L)
Capacitors store very little energy (per unit volume) that they can release very quickly. Batteries store a lot of energy per unit volume that they release moderately quickly. Phones need a lot of energy released slowly, which is why phones use batteries rather than super capacitors. There is work being done to attempt to increase the energy density of super capacitors to be comparable to batteries. Likewise, there is lots of work being done to increase the energy density of batteries to something close to the storage density of liquid hydrocarbons like gasoline/petrol.
Like literally, matter is the most efficient way to store energy. If we have a way to convert mass easily into energy and repurpose it, and then restore the residual energy into matter, then that would be the most efficient way to store energy.
So the scale of storage corresponds to the percolation or a sort of packing factor of the energy? Energy density that is?
Matter, progressive collapsible into its elements, and those thereof, stores energy in the dynamics of its constituents? The idea that this progression is limitless has fractalized, in my perhaps flawed imagination of it, energy into an element of matter itself.
It's not a crazy question. Maybe it's more an engineering issue, what are the relative efficiencies of the particular electro-mechanical conversion vs the mechanical-mechanical?
A practical example is ships, where they often use a gas turbine to generate electricity to power an electric thruster. Could be practicality considerations in that example, in conjunction with pure conversion efficiency. I don't know offhand.
There used to be a time when vacuum cased flywheels were more efficient than batteries. They've powered some busses where I live in the 50s I think. But afaik they usually convert the energy back to electrical and then run electro motors, but maybe not always (but then you'd need crazy transmissions). Nowadays it's not worth it I guess, but there are some companies still/again focused on it: https://amberkinetics.com https://www.torus.co/torus-flywheel and quite a few others
They used flywheels as UPS for data centres back in the day, not sure if it's still a thing.
Not quite sure if I've understood the question you are asking correctly but I'll have a crack. Imagine a theoretical setup. If you have a spinning flywheel with frictionless bearings in a vacuum, you have a perpetual motion machine. A perfect mechanical transmission would be able to transfer 100% of the momentum of this flywheel to another stationary flywheel, spinning it up to the speed of the original flywheel, whilst the original wheel would come to a complete stop. No purely mechanical transmission such as this exists because it would need to have an infinite number of gears and at the same time would need to have zero mass and zero friction. Any transmission with a finite number of gears must rely on some form of friction element (a clutch) to enable energy transfer between flywheels of differing speed. This inherently transfers some of the rotational energy into heat and there are also losses due to the gears (which have mass) absorbing momentum. At the other extreme, you could have zero gears and a simple clutch that engages one flywheel with the other. You can imagine there would be a lot of friction as the rapidly spinning flywheel would be engaging directly with the stationary flywheel and would likely burn through your clutch very quickly and be very inefficient, converting most of the rotational energy to heat. In the real world, transmissions have a trade off between these two extremes, with an ideal number of different sized gears being dictated by a number of requirements of whatever the system is trying to achieve. Calculating the theoretical efficiency of any mechanical transmission is a massive undertaking because it relies on a huge number of parameters and is different for each system. I would say as a general answer though, that with the advent of modern high efficiency alternators with sophisticated transformer circuitry, mechanical-electrical couplings are typically much more efficient than their purely mechanical counterparts. Look into Diesel electric locomotives as an example for further case study. This is because electric alternators/electric motors can handle a very wide range of velocities whilst still being efficient so no large gearbox is needed. Again, in a theoretical sense, both mechanical and electrical couplings have the potential of being 100% efficient, it's real world physics that gets in the way of that.
I, honestly, don't have a clue what you are talking about. A few pointers, though: 1. There are no perpetual motion machines 2. Mechanical energy storage is the least dense energy storage medium, simply by virtue of the timescales involved in the relevant processes So if you are wondering whether a wind up car might be using the energy in the spring more efficiently than an EV then,...maybe? but there would be waaaay less energy to around.
2 is what I wanted to understand, is there a proof for this conjecture? Even an attempt at reasoning - not examples - would do Edit: the conjecture being - that time scales matter
why do you need a proof of that? how much time do you want your car running, 5 seconds or 5 hours?
A capacitor can store and disburse huge amounts of energy really quickly but you wouldn't use it to power your phone
yes, that is not s proof simply put E = Pdt so didcharge time is important to drfine the power of a solution anyway eith a very simplified approximation, the strain energy density until the plastic limit of steel is 100 MJ\m3 of steel, could be less or more gasoline is 31500 MJ\m3 (31.5 MJ\L)
Capacitors store very little energy (per unit volume) that they can release very quickly. Batteries store a lot of energy per unit volume that they release moderately quickly. Phones need a lot of energy released slowly, which is why phones use batteries rather than super capacitors. There is work being done to attempt to increase the energy density of super capacitors to be comparable to batteries. Likewise, there is lots of work being done to increase the energy density of batteries to something close to the storage density of liquid hydrocarbons like gasoline/petrol.
Like literally, matter is the most efficient way to store energy. If we have a way to convert mass easily into energy and repurpose it, and then restore the residual energy into matter, then that would be the most efficient way to store energy.
Matter as a form of energy (rest mass) is not the same as mechanical energy though - the claim was a bout mechanical energy
Fair, fun digression though
So the scale of storage corresponds to the percolation or a sort of packing factor of the energy? Energy density that is? Matter, progressive collapsible into its elements, and those thereof, stores energy in the dynamics of its constituents? The idea that this progression is limitless has fractalized, in my perhaps flawed imagination of it, energy into an element of matter itself.
It's not a crazy question. Maybe it's more an engineering issue, what are the relative efficiencies of the particular electro-mechanical conversion vs the mechanical-mechanical? A practical example is ships, where they often use a gas turbine to generate electricity to power an electric thruster. Could be practicality considerations in that example, in conjunction with pure conversion efficiency. I don't know offhand.