MIT Team Creates Shock That Recharges Your Car 281
An anonymous reader writes "If you had a GenShock, you may not mind those potholes in the road any longer because this new prototype shock actually harvests energy from bumps in the road to save on fuel. A team of students at MIT have invented a shock absorber that harnesses energy from small bumps in the road, generating electricity while it smooths the ride more effectively than conventional shocks. Senior Shakeel Avadhany and his teammates say they can produce up to a 10 percent improvement in overall vehicle fuel efficiency by using the regenerative shock absorbers. They also already have a lot of interest in their design, specifically the company that builds Humvees for the army are already planning to install them in its next version of the Humvee."
In this house we obey the laws of thermodynamics (Score:5, Insightful)
I hope you are being silly. The most efficient way to travel would be a perfectly smooth road, one that didn't suck energy out of the vehicle, in the form of a bump, in the first place.
To truly express the dilemma, you have to weigh the amount of energy used to maintain a smooth road versus the new found energy return from these shocks.
Genious and bullshit (Score:5, Insightful)
Recharging the batteries using movement of the shock absorbers is ingenious!
That they would smooth the ride more than conventional shock-absorbers is bullshit. You can get all kinds of traditional shock-absorbers. American ones for instance are typically softer than European which leads to poor handling and increased fuel consumptions. European ones are harder, and sports-models even harder yet, given the cars better handling at the expense of ride comfort.
If the new absorbers are smoother than traditional ones, it just means the car can't corner, and rides like a pimp car.
In this house we obey the laws of thermodynamics.. (Score:1, Insightful)
...you may not mind those potholes in the road any longer...
You mean "as much." The GenShock isn't going to be 100% efficient and even if it was it can only harvest the energy that actually gets to it. Pot holes will still result in a net loss.
Re:In this house we obey the laws of thermodynamic (Score:5, Insightful)
Which is why this makes sense for off-road vehicles, such as military hummers.
But I agree that poor road maintenance is not just a suck on fuel efficiency, but results in increased costs on the upkeep of vehicles as a whole. (and it takes energy to make and ship those new sway-bar struts that I had to have replaced because of hitting too many bumps)
Bad summary (Score:4, Insightful)
should s/shock/shock absorber/ so we know WTF you're talking about right away.
Re:Genious and bullshit (Score:5, Insightful)
"handling" and "softride" are not a zero-sum game. Suspension can be both better handling and softer than conventional systems. /.-er I did not rtfa, but I assume their suspension is active [wikipedia.org].
being a good
Compared to solar power... (Score:4, Insightful)
This is pretty good.
In their testing so far, the students found that in a 6-shock heavy truck, each shock absorber could generate up to an average of 1 kW on a standard road.
The total insolation at the equator is about 1kW per square meter, so if your solar cells are 20% efficient that's the equivalent of 30 square meters of solar panels.
("up to an average", though... wtf does that actually mean? Oh well, your solar cells only get "up to an average" of 1kW too...)
Re:In this house we obey the laws of thermodynamic (Score:3, Insightful)
I'll take the "poorly modified" up-armored vehicles over a canvas passenger compartment on my patrol of Baghdad any day. When we were in Iraq in 2004-5 my brigade lost a few soldiers, but at least as many and probably more were saved by vehicle armor as were lost. The armor provided some maintenance headaches for sure, but I'd rather (and the mechanics, would rather, especially since they ran in the same vehicles when they went outside) the mechanics have to work a bit harder than having the fatality rate double. Would it have been better if we have an existing light armored fighting vehicle deployed to all of our troops? Yeah. Was the solution a damn sight better than the problem it fixed? Ohh yeah.
1st law of thermal dynamics says . . . (Score:2, Insightful)
"a shock absorber that harnesses energy from small bumps in the road"
It doesn't create energy, it only recovers a certain percentage that would have been lost otherwise.
As such, it'll only be practical on rough terrain, poor quality roads, or when you intentionally drive over potholes . . .
There's no energy IN those bumps to be harvested (Score:1, Insightful)
Sit your car on one all day and you'll get nothing out. That's a crappy way to put it. As an MIT alum, I'd hope the inventors don't describe it that way.
The energy to compress your shocks comes from your gas tank. At best, this is a topping cycle that increases the efficiency of your car engine, not a new source of energy. You could just as well put a piezo transducer on every loose flange and vibrating hose in the engine compartment, and another on the MIT banner flapping off your antenna, and "harvest" the energy from that. It all starts in your gas tank. It's just another variation on harvesting the waste heat from the catalytic convertor.
Given the inevitable losses in energy conversion, I bet you're better off having smooth roads that save you from expending gasoline to oppose the work the bump does on your car to slow it down.
Re:In this house we obey the laws of thermodynamic (Score:3, Insightful)
Might last longer due to the nature of the energy absorbtion, but you're right. A lot of cost and durability issues need to be resolved.
Think along the lines of the shake-charged flashlights. The only things added to a regular shock are a coil and a magnet. The magnet isn't going to wear out in any reasonable time-frame, and a properly insulated and protected coil won't either (unless the temperature starts to affect the insulator - unlikely, and can be mitigated with engineering). I suspect they would last about as long as regular shocks unless they completely replace the standard shock-absorption part. That seems unlikely - a wire breaks (or nothing needs to be powered) and your shocks turn into springs. The mechanical parts will wear out faster than the electrical parts.
The other thing the GP forgot to mention is, current-technology shocks aren't free. They can be more expensive than current shocks, so long as they pay for themselves in a reasonable time-frame, say 2 to 5 years or their lifespan, whichever is shorter.
Re:Repair the roads or fuel our cars? (Score:5, Insightful)
Crappy highway conditions aside, you aren't pulling up to a stopsign/red light that often on the highway. THUS, the regenerative braking can't work.
bottom line, if we keep making little features that add up, we can make an extremely efficient vehicle. Braking and shock absorption have always been energy transfer mechanisms that have just turned energy into waste heat before, now, we can do something with that energy and that is amazing!