DIY suspension generator / regenerator

[hansj3]

my vote is for 4 shocks with a central turbine. although the efficiency may be way down with that

[Daox]

According to an article that I got from a coworker, the MIT team calculated the following:

1 cm of suspension travel
1.5 Hz
spring constant of 160,000 N/m
in a 3000 lb vehicle

Add this all together and you get 1.45 kW available from the suspension.

Now, there will be massive efficiency losses of course, but that is a LOT of power to tap into. The average car needs ~300W to run. So, our system would only need to be ~20% efficient to power a vehicle. If we wanted full alternator output (60A for my estimate) it would need to be ~50% efficient. That might be a bit tougher, especially when you lower the weight of the vehicle to what we normally drive here. Obviously, a heavier vehicle will produce more power.

[NeilBlanchard]

Hi,

If this kind of suspension was combined with wheels/tires that do not absorb ~1/2 of the motion (and they would provide much lower rolling resistance), then more of this "bump energy" could be collected.

[Piwoslaw]

Originally Posted by Daox

Extended periods of idling may be problematic without deep cycle batteries, however starter batteries would probably be fine for the majority of drivers.

During idling, the driver (or driver+passenger ) could jump up and down inside the car, working the suspension...

[theunchosen]

I was actually flipping through this month's popular science and it was one of the major articles. I was rather surprised. I guess someone else got their pop-sci before me.

The idea is particularly useful for you EV folks. Electrical drain from ICE engines is a nuisance and eliminating it would increase mpg. . .but in an electric that kind of "free" energy is enormous(especially at such a low cost compared to solar).

[hansj3]

using mit's calculations how far would you get in an ev? i am aware that forever isn't an answer, and a geo doesn't weigh as much as a HMMWV, but say you take an ev geo with a with a 50 mile range and add these shocks what will it amount to on average?... how ever free energy is still free energy and awesome at that.

[theunchosen]

IF you did it the high-teck MITten way you could get an extra 3-4 miles per hour. You'd get roughly an extra KWHr/Hr and as far as I can tell thats 3-4 miles. Its not huge but it really is free, like sunshine.

If you did it the really easy way with coils around the springs and a magnet mounted on a shaft inside the springs you'd probably get about half that. . .but you could do that whereas the hydraulic fluid and. . .would be heavy and not easy. Better off just spending the time and money you would spend on that system and getting a truly enormous magnet for each coil.

I might test this out this weekend. . .depending on what ends up needing fixed at the shop this weekend.

[Daox]

The only problem with the coil and magnet idea is you're still using the shock absorber to dampen the vast majority of the up and down motion. If you use a hydraulic cylinder (as a shock absorber replacement), you can capture 100% of that energy.

[stevet47]

that is cool. I am definitely going to try this ASAP. I just showed my students how to make electro-magnets in class last week, this is the same basic principle.
Electricity into a coil of wire = magnetic field
Magnetic field into a coil of wire = electricity

It would be awesome if we could ditch our alternators with a few of these!

[hansj3]

so... if you had these and a solar roof panel you might be able to net 4-5 miles given that you park in a sunny area... over several days... if we take the high end that would give an ev 10% in range... i know that wont translate into a longer range vehicle, but thats cool