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MIT's solar car takes a trip in the wind tunnel. The car has an ultra-low drag coefficient of 0.11.  (Source: MIT Solar Team)

MIT's new solar car, shown here under construction, is a wonder of modern engineering, pushing body, battery, solar, and electrical automotive techonology to its brink. The car can travel at speeds up to a maximum 90 mph.  (Source: MIT Solar Team)

A front view of MIT's solar car, Eleanor  (Source: MIT Solar Team)

You can get a good idea of the car's size based on this shot of it with MIT's Solar Team.  (Source: MIT Solar Team)
While highly concept-driven, MIT's new solar car is pushing the limits of battery, motor, and power management technologies

It may look like an Ikea reject, or something from outer space, but according to George Hansel, a freshman physics major at the Massachusetts Institute of Technology and a member of MIT's solar car team, the school's new solar car is a dream ride.  He raves, "It drives beautifully.  It's fun to drive and quite a spectacle."

MIT recently pulled the wraps off its latest solar car, which it plans to enter in the World Solar Challenge, a one-of-a-kind week long race held every year in the Australian outback.  MIT's car shows some real power, offering speeds of up to 90 MPH.  And while unlikely to be coming to a dealership in the next several decades, the school is pushing the latest electrical automotive systems and solar research, which should help to power up the next generation of hybrids and electric vehicles, as well as fueling new utility and solar electronics developments.

Technology from the World Solar Challenge indeed has a way of finding its way into real-world offerings.  General Motors' Sunraycer, which it built with AeroVironment and Hughes Aircraft in 1987, smoked the competition in the race's first year.  And today, the upcoming Chevy Volt, which GM is betting its future on, is the Sunraycer's direct decedent.

Jon Bereisa, a longtime member of GM's advanced-propulsion team and key engineer on the Volt project states, "The unexpected success of the Sunraycer made GM leadership take notice as to what might be technologically possible.  It finished the race across Australia a full three days ahead of its competitors, powered by an electric motor that consumed as much power as a hair dryer, at speeds up to 45 mph, and the solar-powered batteries were still fully charged."

The Sunraycer project was transitioned to the Impact concept car, which then became the EV1.  Despite the EV1's 2003 demise at the hands of a GM crushing crew, the legacy lives on in the Chevy Volt.

For MIT, legacy is equally important.  The 2009 competition will mark MIT's 10th car.  MIT, which competed against GM in the inaugural race, is hoping to sweep the competition this year with its new design, which it has named Eleanor.  The team had to do extensive redesign work due to rules changes in the competition which require the solar cars to have drivers sitting up, rather than reclining, as in past designs.

Despite this obstacle, the team's finished product has a mere 0.11 drag coefficient, compared to a drag coefficient of 0.29 for the current Toyota Prius, or 0.195 for the EV1.  The car features 6 square meters (64.5 square feet) covered in 580 silicon solar cells from Sun Power.  The cells generate approximately 1,200 watts -- about enough power to run a hair dryer or a couple of desktop computers.

However, in the new solar car, that's enough juice to propel the car with a passenger at speeds up to 90 MPH.  The power is stored up in a 6-kilowatt-hour advanced battery pack from Genasun, which features 693 lithium-ion cells.  The battery weighs about 32 kilograms (about 71 pounds) and could give the car enough juice, without solar input, to fuel a trip from Boston to New York.  A hub-mounted motor drives the lone rear wheel.  Two other wheels are unattached to the motor and provide balance.

Why the three wheel design, you ask?  MIT's Hansel describes, "A three-wheel vehicle simplifies suspension design.  It's also traditional."

The vehicles body is built from a chrome-moly steel frame.  This frame is wrapped in carbon-fiber-and-Kevlar paneling to deliver a top half body weight -- with solar cells -- of a mere 40 pounds.  In total, with the battery, the car weighs just under 500 pounds.

The new car will cruise through the Australian desert at a steady speed of approximately 55 MPH. 

Will the drivers take it faster, up to the 90 mph maximum speed?  Some serious limitations apply.  The car's stiff suspension and hollow body will likely start to shake as it reaches high speeds, creating a rumble that can alarm even seasoned drivers.  Describes Mr. Hansel, "Our previous car, Tesseract, was very fast. It was taken up to 85 mph before the driver got terrified.  You reach the driver limit before you reach the motor limit."

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By Regs on 3/3/2009 8:35:01 AM , Rating: 5
Now that is one nerd mobile. Solar panel tech needs to improve a little more so that we don't need much surface space to capture the radiant energy.

But three cheers to the MIT students who sacrificed their week ends (and possibly their sex lives) building this.

By V3ctorPT on 3/3/09, Rating: 0
By suryad on 3/3/2009 10:53:29 AM , Rating: 2
I think that would compromise the aerodynamics of the car would it not if they hacked off the roof?

By Thorburn on 3/3/2009 10:58:27 AM , Rating: 3
Roadsters are awful for drag :)

By chmilz on 3/3/2009 10:56:44 AM , Rating: 5
Sweet ride, but if I can't park the fat chic I picked up at the country bar in the back seat, it's a no-go.

By kontorotsui on 3/4/2009 4:19:44 AM , Rating: 2
With the gas savings, you can afford a motel with king size beds. Enjoy.

By SirMikan on 3/3/2009 12:33:25 PM , Rating: 2
As an alum of another Solar Car team (U. of Michigan Momentum '05) I'm happy to see MIT is back in it after a hiatus for one project cycle. They were some of the best competitors we had.

By Suntan on 3/3/2009 1:13:31 PM , Rating: 3
But three cheers to the MIT students who sacrificed their week ends (and possibly their sex lives) building this.

As a person with an engineering degree, that had classes with some of the nerds that participated on these solar car projects back in the day, I can assure you that no sex lives were forfeited for this endeavor.


By freeagle on 3/4/2009 4:58:48 AM , Rating: 4
I can assure you that no sex lives were forfeited

Because there were none to forfeit?

By albundy2 on 3/4/2009 5:43:51 AM , Rating: 2
why do you say that? is it like band camp?

Then Redesign the Suspension
By ralith on 3/3/2009 9:00:00 AM , Rating: 2
If it is going to shake itself apart due to a known suspension issue before you can the hit top speed doesn't that indictate you need to spend a bit of time redesigning the suspension? Either that or it would seem to indicate they don't expect to run at those speeds in which case they could save themselves some weight by putting in a weaker engine and less batteries.

On a separate note I wonder if they are using the new shocks that generate power in this thing?

RE: Then Redesign the Suspension
By MozeeToby on 3/3/2009 11:15:15 AM , Rating: 2
I would think they know what the issue with the shaking is and how to fix it but that the fix would add weight. Remember, the car is designed for a 7 day marathon not a 2 hour sprint, the top speed really isn't that important and every extra pound is going to hurt your efficiency. I guarantee you, the driver is the lightest person they could find, and he'll be on a diet a couple weeks before the race starts to trim off a few extra pounds.

RE: Then Redesign the Suspension
By FormulaRedline on 3/3/2009 11:25:19 AM , Rating: 2
Also keep in mind the students build this in their free time, which they don't have much of at MIT. Why would they fix the "problem" if they don't need to?

RE: Then Redesign the Suspension
By ralith on 3/4/2009 10:19:00 PM , Rating: 2
Because they are annoyed at not coming up with a optimum solution.

RE: Then Redesign the Suspension
By ralith on 3/4/2009 10:17:54 PM , Rating: 2
If you're not going to run at 90 mph then don't give it a engine that will run 90 mph and get the reduced weight from less motor and batteries. Also if they use the new shocks the other MIT group invented that generate power from the suspension then it seems like they could get the best of both worlds.

RE: Then Redesign the Suspension
By calyth on 3/3/2009 5:45:02 PM , Rating: 2
The extra weight and additional points of failure would be the disadvantages of shocks.

They're not unlike bike parts or camping gear. Light, Durable or Cheap are qualities you want, pick 2.

Sure, in a competition like this, Cheap is relative, but then they'll start finding that making light and durable parts are no easy either. There's a reason why those 11lb bikes are so damn expensive, and a lot of times, stripped down.

RE: Then Redesign the Suspension
By ralith on 3/4/2009 10:27:07 PM , Rating: 2
See other replies I posted.

One thing that did come to mind though is the roads in the Australian outback are essentially wash board dirt roads so maybe it really doesn't matter how much time they spend on the suspension because it would vibrate itself apart due to the darn road if you go to fast. Although all the dirt roads I drove as a teenager got better the faster you drove them (as long as you could still control the car that is).

By afkrotch on 3/3/2009 8:36:17 AM , Rating: 3
Let me take a ride. I bet I can get that car flying apart or airborne. All I need is a helmet and some sports body armor.

RE: Pansies
By FITCamaro on 3/3/2009 10:11:59 AM , Rating: 1
I'm sure the ladies would love it too.

Solar powered cars will never be a reality. There isn't enough surface area on a car that would actually be useful.

RE: Pansies
By suryad on 3/3/2009 4:54:31 PM , Rating: 2
Never is too long a time. I am sure there is plenty of research going on into producing much more efficient solar cells that wont require the whole car to be painted with solar cells :)

RE: Pansies
By FITCamaro on 3/4/2009 9:40:25 AM , Rating: 2
Even if they were 100% efficient its doubtful that you could build a car that would be useful. You'd need a light car. And for it to be light it has to be small. And if its small, there's little surface area to put the cells on.

Take the SMART car for example. It doesn't get much smaller than that for a car people will actually buy. I doubt you'd be able to get enough solar cells on one to make it be able to go any kind of decent speed.

RE: Pansies
By Steve1981 on 3/4/2009 9:50:40 AM , Rating: 2
I also have glaucoma when it comes to a solar powered car for real world use: I just don't see it happening anywhere in my lifetime. the case of something like the Volt, I won't discount the possibility that solar cells could potentially be a cost effective supplement to plugging in, eg that the power they generate would more than offset the cost of the cells.

By Oregonian2 on 3/3/2009 4:27:54 PM , Rating: 2
But does it have room for the groceries when going back home?


RE: Room?
By superkdogg on 3/3/2009 5:06:33 PM , Rating: 2
If you had a slick looking solar car that can drive literally all day long, why would you go shopping or go home?

Just drive that baby until the sun goes down, then call for a ride.

RE: Room?
By tedrodai on 3/4/2009 11:59:10 AM , Rating: 2
Or until you're run over by an SUV, then that's that.

How about a hybrid version?
By shin0bi272 on 3/3/2009 3:16:51 PM , Rating: 2
How about we take the hybrid concept and add solar to it? We can get what 75mpg in the new prius' which is gas/electric. Why not add solar to that too? It wouldnt keep the batteries charged as you drive but you could charge them while the car sat at work or home all day and you might only need to use the gasoline engine when accelerating for a long time or going up a hill. Locomotives use diesel electric engines and go hundreds of miles on a gallon of diesel fuel by using the concept of the electric engine being the primary drive system and the diesel engine is just used to run long enough to recharge the batteries.

By InsanityIdeas on 3/5/2009 8:29:04 AM , Rating: 2
That is not how a diesel electric locomotive works, the only batteries it has are to power auxiliary systems and to start the engine. The electric motors are used to provide much higher torque at low speeds or when starting off than could be obtained from a diesel engine directly driving the wheels. The diesel engine is directly coupled to a generator which is electrically wired to the electric motors that drive the wheels, power is controlled by adjusting the throttle on the diesel engine and the speed controller for the motor. Modern diesel electric locomotives use more sophisticated systems to improve efficiency and reliability but the basic concept is the same. They certainly don't go hundreds of miles on a gallon of diesel, but trains are by design more efficient than road transport when directly comparing the quantity of what can be moved.

The concept of a car that charges itself at work is a good one considering most cars spend long periods idle outside. I doubt it would make a significant contribution to the power required to propel it given the weight of current vehicle designs. The prius might eek out 75mpg, but you can get that from a smaller lighter car without using any hybrid technology, all hybrids provide is small car economy in a big car. Most of the time I am following a prius on my bicycle it is using the engine the moment it speeds up, demonstrating the relatively small contribution of the electric drive. It's just shaving small savings off the problem not making radical cuts.

By Shadowmage on 3/4/2009 12:12:19 AM , Rating: 2
They basically copied the University of Michigan's design...

RE: Copycats!
By FormulaRedline on 3/4/2009 2:22:45 PM , Rating: 2
Are you kidding me? Do you know anything about the solar car competition? Those are about as different as modern entries get. They aren't even the same chassis configuration, MIT has a single drive wheel in the rear with a reverse tricycle layout while Michigan has a regular tricycle layout.

MIT has had a car with this same basic look for fourteen years , since 1995:

Please do your research before you make ridiculous claims. Both MIT and Michigan have long solar car histories and I'm sure the designs were arrived at individually as a result of their evolution.

UMs cars:

Shop Space
By FormulaRedline on 3/3/2009 10:06:06 AM , Rating: 2
The solar geeks were always taking up our shop space at MIT where we were building our Formula SAE car (now that's a real car ;D ). Glad to see they designed a new body though, they had just been reusing the same design when I was there. Of course, they were forced to by the rules, but hey, who's counting?

By TheFace on 3/4/2009 11:06:29 AM , Rating: 2
As in Gone in 60 seconds Elenor? Is it their unicorn?

Crash test
By axias41 on 3/4/2009 4:18:29 PM , Rating: 2
5 starts at crash test...

Trade anyone?!
By bigbubba on 3/4/2009 10:14:54 PM , Rating: 2
Anyone going to go trade their Prius for this?! :p

1990 Called
By iFX on 3/5/2009 3:50:56 AM , Rating: 2
They want their solar car back.

Yeah but...
By FaceMaster on 3/3/2009 6:22:50 PM , Rating: 1
...Can it run (over) Crysis?

By nah on 3/3/09, Rating: -1
RE: ah...
By Parhel on 3/3/2009 10:39:08 AM , Rating: 4
. . . or maybe decendent?

RE: ah...
By superkdogg on 3/3/2009 5:05:27 PM , Rating: 1
The car is neither a dead participant of a court hearing nor a participant in self-indulgence nor in decay/decline.

Decendent is where it's at. ; )

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