When a vehicle speeds up, it uses energy of fuel/battery. Eventually it comes to a stop, which turns the kinetic energy into the heat of brakes. The brakes then cool down transferring the heat to the environment. So instead of heating up the brakes, can an electrical generator be installed to extract at least a fraction of the used energy? Or it won’t be able to stop a vehicle fast enough?
Edit: turns out it is a thing and called regenerative braking. I won’t delete the post though for anyone with the same question
In: Technology
While we’re at it, why don’t we have stators or some kind of turbine on wheels that can generate electricity from tire rotation?
Also, wildly less efficient but still interesting is dynamic braking. Used in locomotives, among other applications.
https://www.trains.com/trn/train-basics/abcs-of-railroading/dynamic-braking/
Also, wildly less efficient but still interesting is dynamic braking. Used in locomotives, among other applications. https://www.trains.com/trn/train-basics/abcs-of-railroading/dynamic-braking/
We are moving towards electric braking technology – just look at the Boeing 787. For now though, it’s complex and would require more upkeep than it’s really worth.
I like your thinking though, maybe one day!
It is done! The technology is called regenerative braking and it is present on nearly every electric vehicle today.
It has some limitations which prevent us from ditching friction brakes altogether, though.
1. It can provide, at best, peak accelerating force, but vehicles are always capable of braking much faster than accelerating, so peak accelerating force isn’t enough.
2. It is restricted under certain situations, such as when the battery is nearly fully charged.
3. It can only provide a braking force at the wheels that are connected to a motor. This can be non-ideal and sometimes even dangerous.
you’re talking about regenerative braking, which is already a thing.
You still only get a fraction back out of it due to inefficiencies and whatnot. And you’re right, it alone isn’t fast enough, so some of the braking has to be traditional, non regenerative.
This exists and is called regenerative breaking. It is used in conjunction with traditional breaking because it would not be sufficient to stop the vehicle fast enough when it needs to be stopped.
Adding to what others have said about regenerative braking – there’s a related braking system called Eddy Current braking.
When you move a magnet past a larger chunk of metal like copper, silver or aluminum the magnet causes electrons in the metal to move (same as with a generator) but the current doesn’t have anywhere to go so it forms eddies in the chunk of metal, that generate a magnetic field that acts in the opposite direction to the magnet being moved near the metal.
The faster the magnet is moving past the copper (usually) the greater the force the induced magnetic field pushes back against the movement. This results in a very powerful braking force when you have a big enough piece of copper and a strong enough magnet.
This is used as a braking system in things like rollercoasters – the system has no moving parts and no contact or operating system so has a lot of reliability for relatively little maintenance.
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