Shock absorbers as GENERATORS

Shock absorbers as GENERATORS

A couple of bright MIT kids recently came up with one of those ideas that makes you go, "Duh! why didn't i think of that?" By simply using the hydraulic action of the shocks to drive micro turbines, they were able to reclaim energy lost to bumps and vertical movement, and increase efficiency by 10%. In the effort to increase battery range as much as possible, this seems like an easy bolt-in component that would boost the Mod S from 300 to 330 miles per charge. Here's the link:

Tesla 1233 | 8 January 2011

According to the article the system is best suited for heavy trucks and could be used to replace the alternator (in heavy trucks). Tesla cars do not have alternators. The battery they talk about recharging is the low voltage lead-acid battery used to start the truck. Tesla cars do not have a lead-acid battery or a starter motor for that matter. I doubt that this system could achieve the voltage necessary to charge the Tesla battery pack. It might be useful for running the electric heaters in a car. However it also might be more economical to recirculate waste heat from the battery and motor to provide cabin heat rahter than add a new system.

In addition to the special shock absorbers this energy recovery system requires hydraulic lines to connect the shock absorbers to a generator and its own electronic control system; all of which would take up space and add weight to the vehicle, not to mention cost.

It might be practical in the future (emphasize future). However, I suspect that improvements in battery chemistry and battery pack design would be more productive and I am sure Tesla is investing in that area.

Douglas3 | 8 January 2011

Actually there IS a small 12V sealed lead battery in front of the front right wheel in a Tesla Roadster. It's a backup power source for some critical car systems.

Timo | 9 January 2011

It doesn't give 10% efficiency boost for road machines simply because there is not enough energy to get that improvement in vibrations which the suspension reduces.

Pretty much same thing as with solar panels. There just is not enough energy there to be worth of the cost and complexity of the system. Not for energy gain. However they could be worth it just because of improvement of suspension (especially smart control they provide), and in that case it would be stupid not to use that energy they generate.

Nicola | 28 January 2011

Yes, obviously, a sedan would have less shock action and generate less power than a heavier vehicle, but it would still produce some. Of course i know electric cars don't have alternators or starters or lead-acid batteries. Do you honestly think anyone on this forum would think those things? Don't be so obtuse. Electric output can be used to charge any kind of battery. No, it would not fully charge the batteries, it would just add a small percentage to the range. It would not require it's own control system, it would just be wired to the existing box. Slight change to the firmware. Weight would be nominal.

qwk | 30 January 2011

Very little gain for the cost. Same with solar panels.

cambrown98 | 5 June 2011

What about an electromechanical actuator based active suspension system similar to what BOSE is doing:

No hydraulics. May not generate that much power, but the performance and ride comfort increases would certainly help Tesla compete with what's sure to be the next big thing in luxury performance sedans.


Kallisman | 30 June 2011

The Bose system uses so much power that they have fitted an extra generator to the ICE of the car, just to power the suspension. So I think it would not be good for the range of an electric car. Except for that it's neat.

Benzman | 6 July 2011

In my oppinion, that the system is useless for gas-powered vehicles, as it is for electric vehicles. For the first type, it generates less power than a usual alternator, for the second type, not enough power to charge the battery, therefore it doesn't justify the investment.

It reminds me of the little fan you put in the window to generate electricity in a car, when you can use the 12V plug...

The power generated from the braking system is not something to waste. The gains are multiple: it minimizes the brake wear (electric vehicles are generally heavier, therfore the brakes wear faster) and it charges the batteries. That is something useful.

There ar so many useless inventions out there, and this goes in the same category...

Hey, I have one: you can generate power each time you sit in the car. You can jam several motors in the seat, so when you seat, it moves and you can generate 1V per 50 pound. Heavier people could make up to 6v... Lol

A.colella | 2 August 2013

Ive been in the industry for a few years and im into electric vehicles and like to give my unbiased opinion...No matter the design, shock generators in a car will generate very small amounts of energy and be insignificant and not even close to worth the investment in research and development....with that said, it would be a great idea to focus on aerodynamics, wheel to ground friction, battery size and weight, vehicle chassis weight etc... these will greatly improve fuel economy and are are easier to implement as opposed to a regenerative shock system...

carlgo | 2 August 2013

Some day suspensions will be electric, no springs or conventional shocks. Sensors will signal the suspension to pick up the wheels and place them back down. It will by like flying, almost.

You can actually program it to do things like make it bank when you corner, like a boat. No dive or squat, load leveling and of course a tie in with various crash preventing technologies like ABS. Tests show that people get confused by this and so you have to build in a little lean and dive simply to give drivers some tactile feedback.

One would think they would draw a lot of power, power being necessary simply to keep the car from collapsing to the ground to start with.

Until the day of truly fast charging, reasonably long range batteries and the facilities to charge them we would have to guess that electric cars will be the last to use this technology.

danielccc | 2 August 2013

Actually I did think about exactly this a few years ago. Instead of small turbines my version had small electric generators/motors, or a static coil and moving magnet arrangement. It would act either as an active suspension or an energy recovery system.

The problem was that I did the math (ballpark) and I came nowhere near 10% energy recovery. For smooth roads it was less than 1%. The suspension doesn't work that hard, so there isn't a lot of energy to recover.

carlgo: An electric suspension would draw no power to keep the car from collapsing to the ground. Shock absorbers don't hold the car, springs do. The shocks simply dampen the oscillations, which is what an electric suspension would do (but more intelligently thanks to sensors). It would not replace the springs.

carlgo | 3 August 2013

Electric shocks alone would have their advantages, but an actual all-electric suspension would have no springs and be more effective.

In practice surely there would be some lock to hold the car up while it is parked. I was just playing with the notion of the car collapsing to the ground like some spent lowrider.

kenarockdedes | 28 August 2015

if able to produce 13~15 Vdc and will charging the 12 Volt battery it will useful for power window, motorized mirror, motorized sunroof, AC fan, lighter, DVD/radio/TV etc all in 12 Volt, because electric car doesn't have alternator, I'll trying to make it, but my design maybe is installed outside the spring, so become an option for car.