Vehicle: Car: Brake
Brake Energy   (+3, -1)  [vote for, against]
Wasted Brake Energy

Every time you drive your car you convert chemical energy to kinetic enery - in theory you can keep moving for ever on that one energy conversion. Unfortunatley this is only true if you are in a frictionless environment. Cars have moving parts and kinetic energy is converted to heat through friction. Okay there isnt much you can do for a lot of this friction but think about where the majority of friction comes from during a drive. The brakes! That's us deliberatly throwing away energy that we've only just put in! Think how much energy it takes to stop a 1/2 tonne car traveling at 80mph! - this is how much energy we have at our disposal when travelling at that speed - think of all the things we could do with it other than making our brake disks hot.

I propose that at the end of every motorway we install giant syringes full of water - drivers wishing to stop can hit the plunger at full speed - this would squirt water into a high water tower where it will have potential energy that can later be converted to electricity through turbines. Either that or have some sort of energy converting brakes (something like a flywheel or spring that gets wound up when you brake and can be used to get you moving again later).
-- ajwhunter, Nov 13 2002

thats their problem.
-- ajwhunter, Nov 13 2002


Anyway,you should always plan your motorway journeys in advance.
-- ajwhunter, Nov 13 2002


Ha! So bad, yet so original.

Welcome to the HalfBakery.
-- phoenix, Nov 13 2002


The flywheel-based storage of braking energy has been done, in fact someone posted something about it on this site--subways, I think.

The giant syringe part, though, is madcap and very good.
-- bristolz, Nov 13 2002


Ford's been playing with hydraulic boost for take-off; when the vehicle slows down, the energy is diverted to pressurize a storage tank, which in effect is very similar to this idea, and workable. You're on the right track, and the zaniness of the thing while using general engineering principles is a good mix. Croissant from me.
-- RayfordSteele, Nov 13 2002


That's a lot like the idea behind the Honda Hybrid and Toyota Prius, genius. Have you been watching to much TV again? The Honda applies resistance to the brake mechanism controlled by a turbine that generates electricity by turning the turbine with the wheel's kinetic force as it is stopping; thus, effectivly stopping the car and charging the battery. This is how it charges its battery that doesn't need to be plugged in like the total electric car. Once again the Japanese are years ahead of us. Well, you at least. Did you go to public school?
-- DrugStoreCowboy, Nov 14 2002


You missed the giant syringe part, [DrugStoreCowboy], and please be courteous.
-- bristolz, Nov 14 2002


See the idea "Magbrakes" (link on upper right of this page) for a related idea, and a link to an article about the flywheels they use in the New York Subway system to recover the braking energy of trains at each station.

I love the image of the giant syringe! Reminds me of those crash barriers made of plastic barrels--many of these are filled with water that is hurled skyward to absorb the impact of the vehicle.
-- krelnik, Nov 14 2002


what about crashes you wont be able to stop at any time
-- redwheel, Jan 04 2005


Perhaps we can install custard filed syringes in the car and link them via some complicated Vernon-like mechanical linkage to the transmission, in such a way that when braking they skirt the custard into pressurized custard-proof cylinders, changing the kinetic energy into presurized volume of custard. Hard to calculate how many kilocustard/hours we'll need to store, though. Bum, I like the syringes idea.
-- clementedelacuadra, Jan 05 2005


Well, I admit the mechanism suggested here is unique, but the overall Idea, "regererative braking", is quite old. It's even baked by those recent-model hybrid cars that are now on the market.
-- Vernon, Jan 06 2005


Woweee Vernon ! ¿Are you seriously ill? ¿Is that you? ¿Sending a very short annotation? Glad to ear you again. Have a nice Ney Year !. Same for everybody !. Of course regenerative braking is old. First Stone Age wheels stored tremendous kinetic energy on its great mass by mean cdg radius by fast rotation (See Yubba-Dooba- Doo). But none used syringes, hein?. They could have made srynges out of the long hollow bones of Pterosaur's wings, or from bamboo canes, say. But custard is a later invention, I believe the first custard filled syringes were found inside the deepest chamber at the Gizeh piramids. Used for mummification purposes, you know.
-- clementedelacuadra, Jan 06 2005


(Drug Store) : Those very inteligent, small, yellow, slanted eyes Orientals (no offense meant), are very inteligent and slanted-eyed. They manage to sell us underpovered cars with a low mileage (see Toyota Prius specs) when state of the art powerful Audi turbodiesels use drops of fuel. See with your eyes, man !. My forty years old air cooled Citroen is doing 55 miles a gallon or runs a hundred klicks burning only four and a half litres of fuel. Admitedly very slow. What I mean, the problem with hybrids is too many energy conversions with the inevitable losses. Regenerative braking helps, but is not all, as we can plainly see. I say the futur is of the fully electric, or alternatively, solar/steam, that is so much lovely. --PD : When you say "no offense meant" you manage to get away with the most outrageous sayings, eh,eh.
-- clementedelacuadra, Jan 06 2005


Sorry, when driving on highways, most of the energy loss is rolling friction from the tires and aerodynamic drag.
-- Freefall, Jan 07 2005


"too many energy conversions with inevitable losses" -- I agree. The best solution I know of (and mostly mentioned elsewhere by others first, here at the HalfBakery) is to (1) replace the battery of a current hybrid car with a flywheel, and (2) replace the gas engine with something more efficient, like a Stirling. Then you start with best available efficiency of converting chemical energy into mechanical energy, and best available efficiency of STORING that mechanical energy for acceleration purposes. (The flywheel only needs to hold enough energy to accelerate the car up to cruising speed a couple of times. Regenerative braking and the efficient Stirling engine will recharge the flywheel in time for the next needed acceleration. The engine itself only needs to be 20 horsepower or so, sufficient to cruise at highway speed. ALL the extra power that auto engines have is there ONLY to allow rapid acceleration, which the flywheel would do MUCH more efficiently.)
-- Vernon, Jan 07 2005


Take a 10 ton RV. It takes a LOT of energy to get it moving and slow it down. Most of its fuel is burned to get it moving from a start and when climbing hills. How about a big bungee cord to store the energy used to stop or slow down (take advantage of gravity on downhill runs instead of wasting it on braking)? A rubber band enhanced heavy vehicle! Can a flexible, high strength steel rod be 'wound' to store that energy? I imagine that even if its useful lifetime was short, before it broke from stress, that loss would be much more than offset by the savings in wasteful organics even if you don't consider the pollution benefits. That giant syringe idea is great but why not put it on the vehicle so when it needs to stop its just a matter of finding something convenient to run into?
-- mikerants, Apr 30 2005


[+] for the originality. I too had posted idea last year which was found similar to regenerative braking system. but application of syringes would be quite original.

a further advantage (not in 100% cases) would be accident prevention by syringes in case driver is helpless due to failure of brake system.
-- vedarshi, Apr 30 2005


How about a more direct energy conversion?

At each end of the motorway, you have a giant see-saw mounted sideways, straddling the two carriageways. On starting your journey, you back up against the seesaw, put the car in neutral, release the handbrake (this is important) and wait. After an exciting while, a vehicle travelling the opposite way reaches the end of its journey by slamming into the opposite arm of the see saw and - wheeeee! - you're on your way.

Gantry- mounted lever-connected versions would operate at slip-roads.
-- Basepair, Apr 30 2005


[basepair] with see-saw system, safety aspect needs to be looked into considering the difference in weight of vehicles on the opposite ways.

and will the vehicle on opposite way decelerate or put in extra effort while my car would be climbing ?
-- vedarshi, May 01 2005



random, halfbakery