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MIT Team Creates Shock That Recharges Your Car
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."
Looks like MIT just gave us a little picklet, will we repair our roads or use the potholes to power our cars?
Is this actually legal since it hurts the oil industry ?
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.
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.
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)
Build it, and they will come^Hplain.
I take it you don't live in a cold weather climate or in a large city. Snow/ice + salt + plows = pot holes. Large cities have notoriously bad roads, it's too hard to repair them with so much traffic.
And it's not just bumpy roads that shocks help with. Every time you turn a corner the shocks are used to keep the car stable.
Personally, I think it's a brilliant idea. The easiest way to become more efficient is to turn the wasted energy into something useful.
"Action without philosophy is a lethal weapon; philosophy without action is worthless."
Cars are brought back to their parents on prom night with a full tank of gas.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Generally speaking you have more handling and fuel performance issues with having too *little* air in the tires. 27% of cars, according to the US DOT, have at least one underinflated tire.
http://www.dot.gov/affairs/nhtsa4601.htm
So what's the problem? Well, as you say, you get a harsher ride from an overinflated tire, but you get far many more problems with underinflation, which is probably far more common. Some of those problems include poor braking, slow steering, poor handling/road grip, and worse fuel economy... worse than can be made up by funky new regenerative shocks.
http://www.straightdope.com/columns/read/225/could-we-conserve-gasoline-by-putting-more-air-in-our-tires
I know lots of people made fun of Barack Obama during the Presidential campaign for his plea to check the tire pressures, but the reality is that drivers the world over could save millions of gallons of oil annually by simply keeping tires inflated properly. In cold climates this also means double checking the pressures when the outside temperature drops by 10 degrees.
Better to pump up the tires than not.
This post brought to you by your friendly neighborhood MBA.
I wouldn't be surprised to see tractor-trailers going hybrid soon. Fuel economy is a HUGE factor for trucking, and they require large engines to maintain speed up large inclines. Additionally, all that weight is very hard to slow down on declines -producing a lot of wear on brakes and power-train (engine breaks). Trains already do it, trucks are next.
"Knowledge is the only instrument of production that is not subject to diminishing returns" -Journal of Political Econom
I've been saying for 5 years now that we should use all the available energy to power electric cars.
I've been saying it for ten! Where the fuck have you been?
I think that this is the way of the future, and MIT did one step.
Now if they take one step back, and one step forward, and one step back... they're doing the cha-cha.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Wonder if I can have this on my bed.
Honey, I know you have a headache, but think of the planet.
I did a ton of shock development as part of my race car engineering job.
We had sensors on the suspension to directly measure suspension travel, with a view towards measuring suspension velocity as part of shock development.
Even on what feels like a perfectly smooth track, there's still a lot of humping and bumping going on.
See http://farnorthracing.com/autocross_secrets6.html for example graphs of suspension velocity pulled right off the car.
DG
Want to learn about race cars? Read my Book
OTOH, if you're running low on fuel/power, just cruise up onto the sidewalk and mow down a few unsuspecting pedestrians. *KaThumpKaThump* *KaThumpKaThump* Presto! Enough juice to make it home (after a quick run through the carwash, of course). Thanks, MIT!!
You do realize that this will only effect hybrid or electric cars right?
Given the specific mention of military hummers, which are most certainly NOT hybrids or electic, it must have some benefit for non-hybrids.
Then again, how difficult would it be to replace the starter and alternator with a motor/generator capable of putting power to the drivetrain? Even if it's only a 5hp sustained, that'd be more than enough to take the 1kw each of the six shocks is capable of putting out(1hp=746W). Switch out the lead battery for a LiIon/NiMH of substantially more capacity. Increased cost, but probably actually lighter than traditional systems. For cold areas, there are LiIon that perform *as rated* at -40C. Not the 'put a bigger battery than you could possibly need in warm weather so you still have enough power to start when the oil is like jelly and the battery has 10% capacity left'.
You'd end up with a mild hybrid that can do stuff like shut off the engine at stops. Oh and stick the energy gained from the shocks back into moving the vehicle.
If they can't get the cost of this stuff under those dollar figures, then they are probably costing more then any savings.
The only problem I see with your figures is that they're explicity talking about trucks and other heavy vehicles. So you might want to redo your figures for 12-20 mpg ranges. Their test mule was a heavy truck with six shocks. Indeed, they also mention that it provides a better ride than traditional shocks, so there's a possible selling point there.
20 mpg/15,000 miles=750 gallons. Save 75 gallons a year(10%), that'd be $150@$2 gas, $300@$4 gas. Ten year timeframe? Could save them $3k, more if they've got a really heavy truck or are driving on particularly bumpy roads.
Then again, I've said numerous times that it makes more sense to make trucks and SUVs hybrid before you start making sub-compact hybrids. More fuel to save, more room to put the components, components end up being a lower percentage of the cost of the vehicle, etc...
I mean, look at the typical UPS/FEDEX panel van. Consider it's usage - stop and go traffic all day in the city for most of them. Right now they have a diesel engine that doesn't get turned off when they stop. How much fuel can be saved if you turn the truck into a hybrid? As a bonus, the heavy battery pack in the bottom of the vehicle would help mitigate the tipping hazards of a tall vehicle like that.
My guess is that their effectiveness is going to go as the shock absorption abilities go and will only be effective for that typical 5 years then severely degrade after that like regular shocks and struts seem to do.
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.
I don't read AC A human right
Let's respond point by point.
...your 2nd paragraph yields number of cars affected...
You do realize that this will only effect hybrid or electric cars right?
Yes. This will only affect some present and most future cars. Sorry to have disturbed you with it.
Ok, let's agree on less than 10% of passenger cars today. I can add that it affects zero% of my car(s) -- an equally irrelevant fact.
The second thing is, if these shocks produce a gain of around 10% in energy recovered, then we can do some math on the economics of it.
We sure can, and the bottom line is that for 5% of the cost of a $20K car, you can get 10% better fuel economy. [2.5% of a $40K car, 1% of a $100K car, 0.1% of one of these] This "spend 5%, get 10%" thing should already be a clue but here is a back-of-the-envelope calculation anyway: over 150,000 miles, a 25mpg car will use 6,000 gallons of fuel. 10% of that is 600 gallons. At today's price, that is about $1,200, FTW. 5 or 10 years from now it will be higher.
Also, 10% more energy translates to a savings in weight somewhere else. For example, the batteries can be 10% smaller, and a 10% battery weight savings could lead to a further 10% gain. Yes, adding a small "Shock Energy Recovery System" to each wheel would add weight, but most likely not equal to 10% of 68KG. And those 68KG only take a Prius for about 5 miles (currently). The next gen is going for 11 miles of electric-only range, so scale the battery weight accordingly. And that is the point -- if you scale the battery range to 50 miles for example, the weight goes to 680KG, and the SERS savings becomes 68KG since it is not necessary to scale the size/weight/cost of the SERS system.
My guess is that their effectiveness is going to go as the shock absorption abilities go and will only be effective for that typical 5 years then severely degrade after that like regular shocks and struts seem to do.
Bad guess -- electrical systems last vastly longer than purely mechanical systems like a shock absorber. SERS could be an induced system, without physical contact, and thus without wear.
And how about just having an extended vehicle range? If you live 5.5 miles from work, your present day Prius will still have to fire up its gas engine. Add SERS and you don't need the gas. If you presently change the oil every 6 months, now you change it every 6.6 months. And unlike engines, and batteries, the SERS can be designed to not wear out at all -- so you extend the total life of your car, bringing further savings.
I think I'd like to let the marketplace decide, rather than choosing to not offer this product because it might just break even in some initial/present day cases. If SERS causes excitement and optimism, people will want to move toward electric and electric/hybrid systems even more -- and that would bring lower prices and more savings.
The future is in plastics, and SERS-like systems. I find your post well reasoned...for a 1900s buggy whip manufacturer.
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