Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Dean Kamen Combines Stirling Engine With Electric Car

timothy posted more than 5 years ago | from the is-there-anything-kamen-can't-do? dept.

Transportation 324

Colin Smith writes "Dean Kamen, (inventor of the Segway) has combined a Stirling engine with a battery-powered electric vehicle based on the Ford Think to provide a fully decoupled electric hybrid car which can run on any fuel which can provide enough heat to run the Stirling generator. Think are also producing a purely battery 'Think City' car which is capable of 62mph and with a range of 126miles." Some stats on the Ford Think: Top speed, 55mph; 0-30, 6.5 seconds; Range, 60 miles on battery.

cancel ×

324 comments

Sorry! There are no comments related to the filter you selected.

stirling engine is a no-go (5, Insightful)

Ancient_Hacker (751168) | more than 5 years ago | (#25697715)

It's been refined for 160 years plus change. So it ought to be really spiffy, right? Well, no. There are definite upper limits to the efficiency of such a device. Most Stirling sites are very cagey when it comes to mentioning the efficiency of what they're selling. For good reason, it's terrible. Like 3 to 6 percent. That kinda explains why it's not in use everywhere, more like nowhere.

Re:stirling engine is a no-go (4, Interesting)

OrangeTide (124937) | more than 5 years ago | (#25697773)

I've seen simple steam boiler engines that are more efficient and more versatile than a stirling engine. And something like the Green Steam engine can be small, compact and cheap and operate in a closed loop system. (I've only seen the Green built up to 10hp, but I think theoretically it should scale to a fairly large size due to the short stroke)

I think the important thing to realize is that people are out there trying new ideas and experimenting with old ideas.

Re:stirling engine is a no-go (2, Interesting)

ScrewMaster (602015) | more than 5 years ago | (#25697991)

I've seen simple steam boiler engines that are more efficient and more versatile than a stirling engine.

You mean like this one [wikipedia.org] ?

Re:stirling engine is a no-go (1)

maxume (22995) | more than 5 years ago | (#25698117)

Doble steamers were way nicer:

http://en.wikipedia.org/wiki/Doble_Steam_Car [wikipedia.org]

The biggest difference was a condenser.

Re:stirling engine is a no-go (4, Interesting)

raynet (51803) | more than 5 years ago | (#25697873)

Actually stirling engine in theory has almost perfect efficiency, unfortunately in practice this is difficult to do. A large, as in huge compared to car engine, stirling engine is easier to make efficient and there are several applications where these are used. And if you run it in reverse you have a great heat pump, often used in cryocooling etc.

Re:stirling engine is a no-go (5, Interesting)

shbazjinkens (776313) | more than 5 years ago | (#25697897)

It's been refined for 160 years plus change. So it ought to be really spiffy, right? Well, no. There are definite upper limits to the efficiency of such a device. Most Stirling sites are very cagey when it comes to mentioning the efficiency of what they're selling. For good reason, it's terrible. Like 3 to 6 percent. That kinda explains why it's not in use everywhere, more like nowhere.

Citation Needed

20 years ago NASA had an automotive Stirling program. Read it and stuff it. [nasa.gov]

They converted a Chevy Celebrity and the results show that the highway gas mileage was increased from 40 to 58 mpg and the urban mileage from 26 to 33 mpg with no change in gross weight of the vehicle. This is NOT a hybrid - it is Stirling only.

By combining the efficiency of the Stirling with the get-up-and go of an electric this is a pretty good thing coming, and I've been waiting a while to see someone to produce it.

Re:stirling engine is a no-go (1)

morgan_greywolf (835522) | more than 5 years ago | (#25698343)

By combining the efficiency of the Stirling with the get-up-and go of an electric this is a pretty good thing coming

I wouldn't describe 0-30 MPH in 6.5 seconds as 'get-up-and-go'. A little known fact is that the Ford Think was actually named after 'The Little Train That Could'. (I think I can, I think I can...)

Re:stirling engine is a no-go (3, Insightful)

fyrewulff (702920) | more than 5 years ago | (#25698869)

I counted it out myself while riding in a car, and 6.5 seconds seems like the normal amount of time to get up to 30mph on city roads, unless you're flooring it every time the light turns green.

Re:stirling engine is a no-go (1)

ChrisMaple (607946) | more than 5 years ago | (#25698523)

According to wikipedia, Stirlings have efficiency equivalent to conventional auto engines, but for the same power they're more expensive and heavier.

As an external combustion engine it's easier to reduce emissions.

Re:stirling engine is a no-go (4, Insightful)

JoeMerchant (803320) | more than 5 years ago | (#25698613)

Too bad that it's being produced by someone who thinks a $20K wheelchair and a $5K scooter are "practical." Maybe he's learned his lesson, but I bet this econobox will come in over $30K to the public.

Re:stirling engine is a no-go (3, Insightful)

CubicleView (910143) | more than 5 years ago | (#25697911)

From TFA

It powers the features that would normally drain huge power from the battery, notably the defroster and heater.

Not much point being efficient at generating electricity etc. if its primary function is to generate heat.

Re:stirling engine is a no-go (4, Informative)

rolfwind (528248) | more than 5 years ago | (#25697955)

I'm no engines expert, but I thought the good part of a stirling engine was that they often are just a few percentage points from theoretical maximum efficiency of a heat engine, about 50%???

http://en.wikipedia.org/wiki/Stirling_engine [wikipedia.org]

I thought the downside is that they take a while to get up to speed. Ford in the 1970s tested a small vehicle with such an engine and they could get it up to speed after 13 seconds. So it should be a natural fit as a battery charger in an electrical car...

At least, that's what I thought when I looked into this a few years back (just as a curiosity, nothing professional mind you).

Re:stirling engine is a no-go (2, Informative)

rolfwind (528248) | more than 5 years ago | (#25698005)

I'd like to add I like Aptera's approach of putting a small engine in an electrical car and letting it charge the batteries. Many vehicles only use a tiny fraction of their horsepower to maintain speed and the rest is for acceleration, so in an car driven by electrical motors - the gasoline recharging engines can be significantly smaller; 5-20hp (? - my civic has 140hp in comparison); probably just a little more than what's needed to maintain targetted top speed (or up-hill considerations).

And a gasoline or better, a diesel engine is plenty efficient already just for this general approach.

Re:stirling engine is a no-go (4, Insightful)

Anonymous Coward | more than 5 years ago | (#25697965)

The efficiency of a stirling cycle engine is a complete NON-ISSUE! for one simple reason.

most stirling engine setups use WASTE heat. And that is the most intelligent use of the stirling cycle. turning waste into power.

so efficient or not. you're getting energy for FREE from something that is complete waste.

even 3% efficient is still 3% you got for FREE and worth it.

Re:stirling engine is a no-go (5, Insightful)

MechaStreisand (585905) | more than 5 years ago | (#25698439)

Nothing is free. There is a cost in weight and a dollar cost to the vehicle itself. 3% efficient doesn't look very good when it's not free at all.

Re:stirling engine is a no-go (0)

Anonymous Coward | more than 5 years ago | (#25698861)

enough heat to run the Stirling generator

I wonder how much it will get slowed down by hauling a ten-foot solar reflector as a power source.

Air Submarines And The Hunky Men Who Love Them (1, Informative)

negRo_slim (636783) | more than 5 years ago | (#25698031)

Like 3 to 6 percent. That kinda explains why it's not in use everywhere, more like nowhere.

'cept for those submarines of the Gotland and SÃdermanland classes... Oh and it helps propel man into the depths of space... here [wikipedia.org] .

Re:Air Submarines And The Hunky Men Who Love Them (1)

JoeMerchant (803320) | more than 5 years ago | (#25698631)

Space, and deep sea, both have a tremendous "cold side" for the Sterling to dump into - which is key to making a Sterling shine.

Even still, the post above quoting 3-6% efficiency is way off base.

Re:stirling engine is a no-go (1)

jacquesm (154384) | more than 5 years ago | (#25698325)

check out the 'whispergen' for something quite a bit better than the figures you are quoting.

Re:stirling engine is a no-go (3, Informative)

JanneM (7445) | more than 5 years ago | (#25698709)

Stirling engines can be fairly efficient if you have the (space and weight) budget to make them big and heavy. For cars they're certainly not a very good idea.

But the main point of Stirling engines isn't efficiency but the fact that they are not only fuel-agnostic; unlike combustion engines or steam engines they don't need any kind of combustion or medium phase-change to operate. Anything that can generate a temperature differential will do. They're also quiet and very reliable (few moving parts).

That makes them well suited for things like backup generators, where you can store them for years on end, then run them on whatever fuel you can get hold of. They're used in submarines too, due to their silent operation and no need for actual combustion to generate enough heat. You could set up a Stirling engine to run on the waste heat from other processes. And they're reversible, so they're used as coolers for certain temperature ranges (overkill for a normal freezer but if you want much colder it's one way to go). Heat pumps are essentially Stirling engines.

Shameless plug ahead: a blog post of mine on Stirling engines here: Stirling Engine [blogspot.com]

Re:stirling engine is a no-go (1)

itzdandy (183397) | more than 5 years ago | (#25698791)

Sterling engines gain efficiency when the delta temperature increases. They are also better at producing a steady "static" power source rather than "dynamic" power source like an auto engine. They should be a efficient way to boost power by converting excess heat for any mechanical system into electrical power.

If the fluid medium is chosen correctly, then the difference between outside air and the engine in a car could be an extra boost to a hybrid system with a small expense in weight because many plastics can handle these temperature ranges and the fluid medium is a near-zero weight gas.

So in conclusion, a sterling engine can suplement an existing cars power but certainly cannot be the primary power source short of a nuclear heat source.

Disruptive technology (4, Informative)

Chairboy (88841) | more than 5 years ago | (#25697719)

When he mentions it being 'disruptive', he's referring to the concept of disruptive technology as written about in The Innovator's Dilemma by Christensen:
http://www.amazon.com/Innovators-Dilemma-Revolutionary-National-Bestseller/dp/0066620694 [amazon.com]

Great read, and the concepts are laid out here:

http://en.wikipedia.org/wiki/Disruptive_technology [wikipedia.org]

If you're not familiar with the concept, it's worth checking out.

Think CITY?? (3, Funny)

caffeinemessiah (918089) | more than 5 years ago | (#25697721)

0-30, 6.5 second

This should have been called a "Think Village", because I doubt any large enough city will have traffic that is forgiving enough to allow a small electric car to reach 30 (either kph or mph) in 6.5 seconds. Seriously, just start counting off 6.5 seconds right now.

Re:Think CITY?? (4, Insightful)

Rei (128717) | more than 5 years ago | (#25697875)

I seriously don't know how Th!nk plans to stay in business with the City versus some of its competitors. Say, the Aptera, for example.

Seating: 2 or 2+2 (Th!nk City); 2+1 (Aptera)
Trunk: 6 cubic feet (Th!nk City); 15.9 cubic feet (Aptera)
Top speed: 60-65mph (Th!nk City); 85-90mph (Aptera)
Accel: 0-30 in 6.5 seconds (Th!nk City); 0-60 in less than 10 seconds (Aptera)
Range: 110 miles (Th!nk City); 120 miles (Aptera)
Charge time: 10 hours at 230V/14A (Th!nk City); 8-10 hours at 120V/15A or 2-3 hours at 240V/30A (Aptera)
Construction: Plastic, aluminum, steel (Th!nk City); Layered composite monocoque (Aptera)
Insurance category: Car (Th!nk City); Motorcycle (Aptera)
Purchase price: $20-25k + $150-$200 per month battery rental (Th!nk City); $27k (Aptera)

Seems a no-brainer to me unless you're one of those people who don't like the Aptera's looks (I think it's one of the most beautiful cars I've ever seen). I'm getting an Aptera :)

Re:Think CITY?? (0)

Anonymous Coward | more than 5 years ago | (#25698123)

except that your aptera looks like an airplane, will be a prime target for thieves (it screams new geeky and expensive) and cant handle bad weather (snow ice high winds etc).

Re:Think CITY?? (1)

Rei (128717) | more than 5 years ago | (#25698167)

Can't handle bad weather? Where's that coming from?

Sadly, I'm legally prohibited from talking about what I know of its drivetrain, but I'm going to have to strongly disagree with you there. But I'd love to know where you're coming from with the whole "winds" thing. It's perfectly smooth all the way around; how are winds supposed to get a grip on it? It may be light, but it's even more aerodynamic than it is light.

Re:Think CITY?? (0)

Anonymous Coward | more than 5 years ago | (#25698297)

You didn't touch the snow/ice part. Where I live I'm lucky to see a snow plow once a year (we have 3 to 4 months of snow). They just don't make it this far out of town.

Either way, it looks like wanna-be futuristic ass.

Re:Think CITY?? (1)

Rei (128717) | more than 5 years ago | (#25698745)

As I said, I've signed an NDA, so I'm legally prohibited from talking about the drivetrain. Which is what this conversation would delve into.

Re:Think CITY?? (0)

Anonymous Coward | more than 5 years ago | (#25698389)

you clearly either have never driven ar or are a complete idiot. drive in a snowstorm with high winds and watch multi ton tractor trailers get thrown around.
your aptera is a toy.

Re:Think CITY?? (0)

Anonymous Coward | more than 5 years ago | (#25698445)

Tractor trailers are big and square. The force imparted by wind is (more-or-less) proportional to the surface area exposed.

I'd rather be in a "toy" than a truck in a blizzard, thanks.

Re:Think CITY?? (1)

Neoprofin (871029) | more than 5 years ago | (#25698537)

You've clearly never driven what amounts to a giant sail on wheels.

Yes, it's much worse with an empty trailer, but even with a full one high winds make for a long day.

Re:Think CITY?? (1)

budgenator (254554) | more than 5 years ago | (#25698957)

I like everything about the aptera, except that one drive wheel rolling in the grease-pit. It just doesn't seem like the greatest idea. Where I'm from the center of the lane is a oily slimy mess in the rain and a pile of icy slush in the snow.

Re:Think CITY?? (1, Funny)

JoeMerchant (803320) | more than 5 years ago | (#25698645)

I have a wife and two small children, which one do I tow behind the Aptera in a trailer?

Re:Think CITY?? (1)

Rei (128717) | more than 5 years ago | (#25698809)

Ah, the "all vehicles must be one size fits all" myth rears its ugly head once again.

I'd wager that half of all of the vehicles in the US see more than two passengers once a month or less. No, it's not a suitable replacement for the other half of all vehicles. But trying to make all vehicles do all jobs is a good way to ensure that they do one or more of those jobs poorly. A commuter or errand vehicle needs to get a passenger or two and some cargo from point A to point B. It doesn't need to be able to haul around a family of Mormons and their bicycles.

Re:Think CITY?? (1)

JoeMerchant (803320) | more than 5 years ago | (#25698929)

My daily driver has 2 seats (Miata), but after taking up one garage slot with that, the other better be able to haul all 4 at one time - if Miatae got 60mpg we could just take two, but sadly, they don't.

Re:Think CITY?? (3, Insightful)

smart.id (264791) | more than 5 years ago | (#25698339)

Offtopic, but related to your sig: AC comments aren't anonymous when logged in. Try posting as AC while logged out, then moderating your comment.

Re:Think CITY?? (1)

ion.simon.c (1183967) | more than 5 years ago | (#25698487)

Heh. 0->30Mph @ ~6.5 seconds is exactly how I drive.
The folks in my American city seem to tolerate it just fine.

*yawn* (0)

Anonymous Coward | more than 5 years ago | (#25697727)

62mph, 126 mile range. *yawn* Unless these things are both safe and ridiculously cheap, who cares? No one will buy one when they can have a "real" car for a few bucks more.

Re:*yawn* (3, Insightful)

OrangeTide (124937) | more than 5 years ago | (#25697809)

stirling engines are ridiculously safe. And if you mass produced them on the scale that typical car engines are mass produced they would have to be a fraction of the price. I don't agree that it's a good design to go with, but I can't argue with the price for the components.

Re:*yawn* (3, Interesting)

zappepcs (820751) | more than 5 years ago | (#25698049)

But here is the deal... this is a START. Better things are coming. There are other ways to hybridize a power train. Several really good ideas for recovering energy that is typically wasted in current vehicles will help, _more_ efficient engines help, better battery technology helps, more efficient solar cell technology helps, more efficient electric motors helps, and most of all a populace willing to accept smaller more efficient vehicles will help. It will take time to put it altogether and make it usable.

You should not be expecting a revolutionary vehicle or power train technology to come along next Tuesday at 2:37 p.m. It will take time. If instant success at the end goal of technology were possible we would not be following Moore's Law at all. We would simply have leap-frogged to the end-game technology. Let's not even go to that thought that alien technology would help if the government would release the information from Area 51. I'm quite happy that there are folk working diffidently to create things that will help us arrive at the end goal - very efficient modes of travel. Note that automobiles are not the only place that improvements can be made.

Safe and ridiculously cheap is what you will not have for a while yet. They will get there. There are private groups working on electric and hybrid cars as well as very cheap cars. The no one you speak of are the same people that think driving a hummer or huge pickup is ok since it only costs a few dollars more. Not everyone has those 'few dollars more' to waste.

Safety? Are motorcycles safe? If there were far fewer SUV's and other big vehicles on the road, safety issues change a bit. No vehicle is safe enough to drive head first into a concrete bridge upright at 70 MPH. Safety is a subjective word and ideal. If you want to drive around in a tank, I'm pretty sure that more than 50% of the populace is okay with you having to pay quite a bit extra for the privilege. Good luck with that.

Re:*yawn* (3, Insightful)

Rei (128717) | more than 5 years ago | (#25698141)

Small and light doesn't have to mean unsafe. Example: rollovers. Not only are big, topheavy vehicles like SUVs more likely to roll over, but they're also more likely to crush their occupants. Big and heavy means more weight trying to crush the roof. Furthermore, more modern materials can reduce weight while *increasing* strength./ I am legally prohibited from stating what I've seen in regards to the Aptera, but I'll just point out that there's a video on YouTube of an Aptera employee slamming a large hammer into the vehicle's shell with absolutely no damage. Go try that with your car sometime and see if you get the same results. Lastly, big and heavy often means less maneuverable which means more likely to get into an accident. There's this strange notion in this country that accidents are inevitable, so you better armour up; however, greater maneuverability and lower stopping distances means lower odds of getting into an accident in the first place.

Re:*yawn* (2, Insightful)

zappepcs (820751) | more than 5 years ago | (#25698583)

Absolutely right on! Safety is not common sense in many cases. Look at F1 racing vehicles. They move at incredible speeds and consequently, when they crash it is a sight to behold, yet because their cockpit is designed with lightweight and very strong materials, drivers survive all but the most devastating of crashes. Those materials push up the cost of the vehicle, but if there are several million vehicles made every year with such materials, the cost of manufacturing with those materials will go down. Not even scifi dreamed materials will stop a guard rail from pushing it's way through the vehicle if you hit it head on. For pretty much everything else, there are safe ways to design a vehicle that will protect it's occupants at the cost of the vehicle's structure. You do NOT need to drive a tank.

I've thought of this quite a bit, and I think that Home Depot has the right idea to reduce some of the need for big vehicles. If you buy huge volumes of stuff from them, they will rent you a truck for $20 to take it home. So you can ride your bicycle to Home Depot and buy a fridge, and supplies to fence in your yard, rent a truck to get it home, then return and get your bike. This is one way to reduce the need for bigger vehicles. There are others that will help design around the problems of delivering bulk materials, transporting many passengers etc. It will take time, but we will get there. Every effort helps.

If one man, or one team should or could have all the answers, Thomas Edison would not have had to spend so much time perfecting his version of the light bulb. With that, here is a hat's off to materials scientists. They will find a material that is almost as light as plastic and has the needed strength to replace steel in vehicles. Situations like that the USA finds itself in right now will help drive the process of finding those materials. Please let's also not forget what kind of contributions that NASA and DARPA have given us, and can continue to give us if they are funded properly.

Fret not, good things will come our way.

Re:*yawn* (1)

Deadstick (535032) | more than 5 years ago | (#25698597)

But here is the deal... this is a START.

-Let me tell you how you can make a ton of money with Amway!

-How much are you making now?

-Hey, we're just starting out.

rj

Wondering what a Stirling engine is? (4, Informative)

mgkimsal2 (200677) | more than 5 years ago | (#25697757)

Wonder no more [wikipedia.org]

"A Stirling engine is a closed-cycle regenerative heat engine with a gaseous working fluid."

As with many of these hybrid and electric car announcements, it'd be great if I could really go buy one, and have it be inexpensive. We're always just "2-3 years" away from these things reaching market, and "eventually" being affordable by regular folks.

Perhaps some Indian or Chinese company will make these and sell them here for under $10k. That would spark a huge revolution. Hybrids at $24k don't change people's buying habits enough to cause a huge shift in demand.

For better or worse, I think we'll see an alt-energy evolution in the US, rather than a revolution.

Re:Wondering what a Stirling engine is? (1)

Rei (128717) | more than 5 years ago | (#25698101)

We're always just "2-3 years" away from these things reaching market,

Name one EV from any remotely serious contender that was 2-3 years away a few years ago that isn't available now.

There were lots of serious commercial EV projects back in the late 90s and early 00s. Once the CARB ZEV mandate was overturned by the courts, however, the programs all disappeared. However, the recent high gas prices, a rising green movement, concern over global warming and an increasingly volatile middle east, and so on has led to a new resurgence even without the old ZEV mandate. 2-3 years ago, however, there were almost no EVs being developed with serious plans for commercial release -- just small-scale testbeds, home conversions, and concept cars. One exception would be the Tesla Roadster, and guess what? It's here today.

Re:Wondering what a Stirling engine is? (1)

TheRealMindChild (743925) | more than 5 years ago | (#25698571)

Not only that, but the mere pittance that you save on fuel efficiency of a hybrid, you certainly make up in the cost of repairing the overly complex system when it breaks.

Diagram (5, Funny)

russoc4 (1223476) | more than 5 years ago | (#25697759)

For those of you who do not know what a Stirling engine looks like, Wikipedia has a very detailed diagram [wikipedia.org] .

Re:Diagram (3, Funny)

Anonymous Coward | more than 5 years ago | (#25697803)

I can't find the vas deferens, is there another diagram?

Re:Diagram (4, Funny)

ScrewMaster (602015) | more than 5 years ago | (#25697909)

I can't find the vas deferens, is there another diagram?

Well, there is a vas deferens between a Stirling Cycle engine and a conventional internal combustion engine.

Re:Diagram (0)

Anonymous Coward | more than 5 years ago | (#25698373)

That's a great joke, but I wonder what the chance is that you are replying to yourself?

Re:Diagram (1)

ScrewMaster (602015) | more than 5 years ago | (#25698747)

That's a great joke, but I wonder what the chance is that you are replying to yourself?

Nah, too much work. I'd have just done it all in one message under my regular nick. I once used that as a pickup line, "You know, there's a vas deferens between us." "Seriously? What would that be?"

And you're right. She wasn't that bright. But it wasn't her frontal lobes that I was interested in.

Then again ... yeah, maybe it was at that.

Re:Diagram (0)

Anonymous Coward | more than 5 years ago | (#25698423)

Who was it? Your great, great grandfather who, when he looked down into the North Valley, said, "Ah,Van Nuys"?

Re:Diagram (1)

Arthur Grumbine (1086397) | more than 5 years ago | (#25698033)

From the Discussion page for that image:

...could this rendering be more phallic?
- Yes. It could be animated.

Wow. More of the same. (3, Insightful)

schnikies79 (788746) | more than 5 years ago | (#25697775)

Great acceleration and no range. I don't care if it takes me 12 or 20 seconds to reach 60mph if I can go 300mi/charge, with the heat, headlights and windsheild wipers on.

Like I just did yesterday.

Re:Wow. More of the same. (1)

ScrewMaster (602015) | more than 5 years ago | (#25697925)

with the heat, headlights and windsheild wipers on.

Forget those. I want a car that can do all that with the air conditioning on full.

Not fast enough (3, Interesting)

MMC Monster (602931) | more than 5 years ago | (#25697781)

Ford Think: Top speed, 55mph; 0-30, 6.5 seconds; Range, 60 miles on battery.

0-60, never. :-(

The problem isn't the top speed being less than 60 mph. The problem is that as vehicles get close to top speed they tend to be less responsive to the accelerator.

With a top speed of 55 mph, this is relegated to situations where you know you will never end up on a highway... Heck, most cities have some highways in them (I know that Manhattan, New York, has a couple where you can legally go 50mph and sometimes see people hit 75mph).

Re:Not fast enough (3, Interesting)

OrangeTide (124937) | more than 5 years ago | (#25697851)

If you want to go less than 60mph, excluding yourself from highway travel in the US (and most other countries). Then it seems like it would be easier to just get a scooter, a gasoline one can get over 150mpg these days. Electric ones exist too, but so far I have been unimpressed. But scooter might only cost you $3000 new, and one that is less efficient might only cost $300 used (but in good shape).

Re:Not fast enough (2, Interesting)

Cyberax (705495) | more than 5 years ago | (#25697947)

Scooters are the most unsafe road vehicles. It's damn too easy to get yourself into a road accident. Most cities are just not planned for scooters or bicycles.

I used a scooter for about two months and then sold it, because I value my health too much.

Gas Turbine? (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#25697837)

Looking at the comments here, the Sterling engine seems pretty useless still.

So how about a gas turbine engine instead? http://en.wikipedia.org/wiki/Gas_turbine

Should provide alot more power for the heater/ac, and be able to recharge the battery on the go.

Re:Gas Turbine? (1)

iminplaya (723125) | more than 5 years ago | (#25698497)

Where have you been [gradywilliamkerr.com] ?

Re:Gas Turbine? (1)

gyrogeerloose (849181) | more than 5 years ago | (#25698569)

So how about a gas turbine engine instead?

It's been tried, largely by the railroads during the last "energy crisis" back the 1970s. There were two main problems they had with gas turbines. One was slow throttle response; it takes them a while to spool up. That might not be a big issue in a hybrid set up. However, the second problem is more dire--poor fuel economy at idle. They found that gas turbines used almost as much fuel at idle as they did at full throttle. That's exactly what you don't need in a hybrid.

Re:Gas Turbine? (1)

superdave80 (1226592) | more than 5 years ago | (#25698637)

Why would you have it idle in an electric hybrid? When the battery gets to X% of charge, switch on and charge the batteries. When the battery reaches 100% charge, shut off.

Re:Gas Turbine? (1)

gyrogeerloose (849181) | more than 5 years ago | (#25698707)

Yeah, you could, but then you run into the first problem: you'd have to wait a very long time for the turbine to spool back up to speed the next time you needed it.

Re:Gas Turbine? (1)

superdave80 (1226592) | more than 5 years ago | (#25698805)

Are we talking minutes? If so, then the battery will provide enough of a buffer while it spins up to speed. If we are talking hours, then this would be a major problem.

Re:Gas Turbine? (1)

gyrogeerloose (849181) | more than 5 years ago | (#25698963)

Probably about three to five minutes, depending on the size of the turbine. I imagine that could be worked around but I think it would be enough of an efficiency hit to make it less desirable than other power sources.

Odd name (0, Troll)

Swizec (978239) | more than 5 years ago | (#25697887)

If your product needs to resort to odd spellings, like replacing the i in Think with an exclamation mark, that means you are dealing with a bunch of marketing hype and are trying to cash in on a fad instead of doing something useful.

Re:Odd name (1)

gyrogeerloose (849181) | more than 5 years ago | (#25698633)

Yeah, I know, we all hate marketers. Truth is, though, they're necessary. As irritating as marketing-speak can be, it frequently does get the job done. If I have to put up with a misplaced exclamation mark to see an workable electric vehicle on the road, I think I can suffer through it. Hell, Apple's lower-case "i" at the beginning of their product names used to bug me too; now I have an iPhone.

Okay, I'll get off your lawn now.

Couple of things bother me... (1, Troll)

Sooner Boomer (96864) | more than 5 years ago | (#25697895)

...in the article. First is "The prototype vehicle, a zippy two-seat hatchback...can go 60 miles on a single charge": second, "It can use any fuel, from biodiesel to natural gas; it burns clean".

On the first comment, 60 miles for some is less than their daily commute to work. And this is without any side trips to pick up kids, groceries, dry cleaning, etc. I realize that the big "Woo-Hoo" of this project is the back-up Sterling engine, but its main selling point is the no-emissions electric power.

Second is the comment about "burns clean". I takes a *tremendous* amount of design work to get an internal combustion engine to "burn clean" using a single fuel; making it a "universal fuel capable" and still "burn clean" will be impossible. This appears to be an exterior combustion engine (no spark plug, pistons, etc) - for lack of a better word - and will increase the difficulty of clean burning beyond the impossible to mearly fantasy.

This is an interesting idea. It will revolutionize transportation the same way that the Segway did.

Re:Couple of things bother me... (0, Redundant)

klaun (236494) | more than 5 years ago | (#25698109)

I(sic) takes a *tremendous* amount of design work to get an internal combustion engine to "burn clean" using a single fuel; making it a "universal fuel capable" and still "burn clean" will be impossible.

You realize that a Stirling engine is an external combustion engine, right?

Re:Couple of things bother me... (5, Insightful)

MartinSchou (1360093) | more than 5 years ago | (#25698143)

60 miles for some is less than their daily commute to work.

Ah, yes, the horrors of a car that won't fulfill EVERYONES needs. How about this - the people who drive more than 60 miles in a day can get another car. Maybe one with a bigger range.

People who need to drive 150 mph can get a powerfull sportscar - maybe even one that'll only do 2 mpg flat out.

People who need to haul a ton of stuff could get a different kind of car. Maybe one with a nice big flat section where you'd have the rear seats. Maybe a "flat bed" of sorts.

The people who have a need to drive 6 kids and their dogs every day could get something like a bus, but smaller. Miniature bus of sorts.

And maybe people like you could start to consider that there is no car in the world, that fulfills EVERYONES needs at once.

Re:Couple of things bother me... (5, Insightful)

Rei (128717) | more than 5 years ago | (#25698251)

Exactly. On the one or two times per year that I need a truck, *I Rent One*. I don't keep a truck around at all times for the offchance that I might perchance need one. Why do people feel the need that they must have a vehicle that can do everything when they'll mainly just use it for their daily commute?

Re:Couple of things bother me... (2, Interesting)

poopdeville (841677) | more than 5 years ago | (#25698573)

People who need to drive 150 mph can get a powerfull sportscar - maybe even one that'll only do 2 mpg flat out.

Nobody wants a sports/race car that only gets 2 mpg.

Gasoline is heavy. And energetic. Better fuel efficiency means you can carry less of it, and get more (speed) out of it.

Admittedly, sports cars are relatively wasteful, since they are tuned for maximizing speed. But this necessarily involves maximizing the amount of energy extracted from fuel, which is the SAME goal econo-car makers are trying to achieve. Econo-car makers are only getting there now because of a LOT of engineering by Honda, Toyota, Porsche, Ferrari, etc 10 years ago.

Re:Couple of things bother me... (0)

Anonymous Coward | more than 5 years ago | (#25698291)

Actually external combustion can be made cleaner than IC; for one thing you can make it a steady-flow system rather than intermittent. IANAChemEng but I imagine that continuous combustion at low pressures is inherently cleaner. Just look at any fossil fuel plant and compare the emissions to that of a car engine (though economies of scale are bound to be significant when you have to scrub so much exhaust).

As for universal fuel, you can power a stirling engine from any source of heat. It would be a lot easier to switch fireboxes or whatever flash word they use than to convert a compression ignition diesel to a spark ignition petrol.

Admittedly it's overly optimistic to expect the ability to simply pour whatever flammables you want into the tank and get a clean burn (Unlike Mr. Fusion) but imagine if they introduced a methane burner... it might be possible to fill up at home from the gas main and sidestep the issue of a lack of infrastructure that faces the likes of hydrogen. Just bear in mind that flexibility in fuel is a lot less of a problem when you don't have to deal with injectors that cycle on the order of 10Hz with functional dimensions on the order of a micron.

And please, it's Stirling, with two 'i's: it should be in your title bar FFS. No-one expects you to RTFA before you post an opinion but you could at least pay attention to the damn title.

Thermodynamics 101 (4, Insightful)

GrahamCox (741991) | more than 5 years ago | (#25697927)

Why don't the inventors of these various electric cars do some basic sums? If you're going to have any sort of hydrocarbon fuel involved then use the most efficient conversion possible to electric power given the space constraint of a practical vehicle. Right now that's a fixed-speed diesel engine at approaching 50%. All these 'exotic' heat engines like Stirling etc. are dead in the water when it comes to basic thermodynamic efficiency. If you don't start with a reasonably efficient conversion you are not going to end up with a vehicle that is even slightly practical.

Re:Thermodynamics 101 (1)

Rei (128717) | more than 5 years ago | (#25698027)

1) Even the diesels in large trucks and busses are only about 45% peak efficiency
2) Peak efficiency != average efficiency. Average efficiency is notably worse than peak.
3) Engine efficiency != vehicle efficiency. You have to factor in parasitic losses.

Re:Thermodynamics 101 (3, Interesting)

theapeman (1068448) | more than 5 years ago | (#25698093)

But the engine in a truck or bus is not fixed speed. It varies according to driving conditions, and there is a loss in efficiency due to the need to allow for the flexible load. If you use an engine merely for charging the battery then it can be a fixed speed, fixed load engine - I.e. it can run at peak efficiency whenever it is running, and the efficiency can be higher than a more flexible engine.

Re:Thermodynamics 101 (1)

JoeMerchant (803320) | more than 5 years ago | (#25698665)

Dean has a soft spot for Sterlings.

Re:Thermodynamics 101 (2, Informative)

evanbd (210358) | more than 5 years ago | (#25698781)

Sterling engines in theory approach the Carnot limit. In practice, they do very very well compared to other engines, especially on a weight basis. However, they also have problems that normally make them inappropriate for cars. They don't do well with variable outputs, and they don't start up rapidly. Over the normal operating range of a car engine, diesels do much better. If, however, you could run it at a fixed speed and not care about startup time, then the Sterling engine starts to look good. And, of course, a series hybrid with large batteries (or an electric car with a battery charger, depending how you look at it) is exactly that.

Of course, there are other problems with Sterling engines -- unknown long-term reliability, for example -- that are likely far more relevant. But efficiency is decidedly not the reason to avoid them.

The Uri Geller of industry (0, Troll)

gilgongo (57446) | more than 5 years ago | (#25698021)

Dean Kamen - "Inventor of the Segway"

Ah, Dean! Dean Kamen! Wonderful inventor and free-thinking genius!

Either that, or a manipulative self-promoter more interested in hyping his way to riches than actually making a difference with anything.

Perhaps he might change the world this time. Or maybe not. I doubt he really cares.

Re:The Uri Geller of industry (4, Informative)

abigor (540274) | more than 5 years ago | (#25698179)

Well, I'd say his inventions such as the portable dialysis machine, the auto-syringe technology for people who require round the clock injections, and the wheelchair that can climb stairs made a tremendous difference. These medical inventions restored a reasonable standard of living to a great number of people, and are the foundation of his current fortune.

Re:The Uri Geller of industry (1)

nate_in_ME (1281156) | more than 5 years ago | (#25698245)

Not to mention his "invention [usfirst.org] " of a way to actually get students to want to go to school for what are commonly referred to as the STEM professions...

Re:The Uri Geller of industry (1)

harmanjd (414263) | more than 5 years ago | (#25698973)

Thanks for posting about that group. Looks very interesting.

Re:The Uri Geller of industry (-1, Troll)

gilgongo (57446) | more than 5 years ago | (#25698287)

Well, I'd say his inventions such as the portable dialysis machine, the auto-syringe technology for people who require round the clock injections, and the wheelchair that can climb stairs made a tremendous difference.

OK cool. I have nothing against the invention of expensive stuff for rich people.

Re:The Uri Geller of industry (1)

abigor (540274) | more than 5 years ago | (#25698381)

These medical inventions are sold by companies like Johnson and Johnson and are not exclusively for the rich - the AutoSyringe and the dialysis machine in particular are very common and were basically life-changing for a tremendous number of people. Or maybe I misread your reply?

He just likes building neat stuff (3, Insightful)

zogger (617870) | more than 5 years ago | (#25698561)

I met the guy and talked to him for awhile at a medical tradeshow when he had a really cheap 10 foot backwall booth and the most amazing piece of gear on the whole show, beat the snot out of all the big blinkenlights booths and their stuff, the go most anyplace crawling, climbing wheelchair thing. He's opposite of marketing, just thinks 18 miles away from some box all the time..then builds it and it works. Whether or not it sells marvelously or not, the dude is a rare man, a combination far out pure research scientist and practical engineer, he figures out how to make sci fi stuff actually work. Our society *demands* marketing and short term megaprofits though, so he's stuck sometimes. He's the kind of guy just needs some billionaire to adopt him as a pet project and turn him loose, so he doesn't need to worry about funding ever again. If even one out of ten things he makes really takes off, I mean to the general public and outside of medical specialties, yes, it will be worth it.

Re:He just likes building neat stuff (1)

JoeMerchant (803320) | more than 5 years ago | (#25698797)

Uh... when did you meet him? Last time I met him (2003, I think) he had his own mountaintop dream home (complete with enclosed helicopter garage), a private island chosen because it was in helicopter range, Citation jet, and what appeared to be a prototype generation company staffed with 200 people just so he could turn out his ideas as quickly as possible. He didn't seem to need adoption. Besides, his folks still hang at the house - mum made snacks for us.

Stirling not connected, not enough to power car. (4, Informative)

guidryp (702488) | more than 5 years ago | (#25698053)

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/10/27/sv_deankamen.xml [telegraph.co.uk]

I read several articles on this when news first broke. The above indicates the Stirlin isn't even connected. When it is, it doesn't produce enough power to actually move the car. Kamen has a 1KW Stirling that is about the same size as what is pictured and other articles mentioned it as a "trickle charger".

In this case the Stirling is essentially a novelty, it doesn't drive the car when the battery is run down.

Re:Stirling not connected, not enough to power car (1)

JoeMerchant (803320) | more than 5 years ago | (#25698815)

There was a lot of hype about "Ginger" (the silly scooter) being Sterling powered before it came out... I haven't seen that version yet.

Just please tell me... (0)

Anonymous Coward | more than 5 years ago | (#25698061)

Just please tell me that the idea of combining engine of type 'X' with an electric generator and putting it in a car is not patented.

Re:Just please tell me... (1)

iminplaya (723125) | more than 5 years ago | (#25698609)

I'm just going to have to let you sort it out [74.125.95.104]

Too Slow (2, Insightful)

caller9 (764851) | more than 5 years ago | (#25698075)

Just by looking around on the road you can tell people are chomping at the bit to drive a tiny tin can looking car, especially if that car is also slow as hell. In fact, the less likely (real or perceived) someone with boobs will give it a second look, the better.

Wait, scratch that, the exact opposite is true.

How about something between the Tesla Roadster and the Smart car. A mid-sized sedan style vehicle that is a plug-in hybrid with a constant RPM diesel generator when needed. Or fuel cells whenever Hydrogen refueling becomes a reality.

0-30 in 6.5 seconds? Sheesh. Better buy a dorky bumper sticker right off the showroom floor. This will give the people waiting behind you at the green light something to laugh at while they try furiously to pass you.

Re:Too Slow (4, Funny)

Miseph (979059) | more than 5 years ago | (#25698419)

Just by looking around on the road you can tell people are chomping at the bit to drive a tiny tin can looking car, especially if that car is also slow as hell. In fact, the less likely (real or perceived) someone with boobs *and shaved armpits* will give it a second look, the better.

Fixed that for you.

Wood burning car? (2, Funny)

kramer (19951) | more than 5 years ago | (#25698355)

I'm looking forward to being able to toss a couple armfuls of firewood in the trunk of my car and running errands.

Re:Wood burning car? (1)

JoeMerchant (803320) | more than 5 years ago | (#25698837)

I'd like to have wood burning as an alternative... use whatever the pumps are selling normally, but having a choice is nice.

This is not a Ford (1)

howcome (618813) | more than 5 years ago | (#25698417)

Ford sold Think in 2003. The unit Dean has been playing with is a new model produced within the last year. Here's the full story: http://en.wikipedia.org/wiki/Th!nk_City [wikipedia.org]

why use the stirling when there is solid state (1, Interesting)

Anonymous Coward | more than 5 years ago | (#25698465)

Does anyone remember this solid state engine [johnsonems.com] from the super soaker guy?
That might be a better method to turn heat to electricity.

Also there are some blanket claims in the article that really need some more detail:
"...It can use any fuel, from biodiesel to natural gas; it burns clean; it can even be programmed to turn on so the battery and car are all warmed up by the time you get in."

I assume that the fuel is being burned as a method used to heat the stirling engine. How can this be claimed to be burning clean? The methods used would need to be explained in detail to be convincing of any major innovation here.

Stirling sinks, give me these three instead: (0)

sjs132 (631745) | more than 5 years ago | (#25698507)

The stirling is DEAD. Has been for 100+ years. Yep, it's a cool toy, but thats about all. Get over it... Instead I'd like to see more Hydrogen based fuel infastructure to aid the adaption of Hydrogen based vehicles... Compressed Natural Gas and Conversion kits to turn my Van over to CNG (We've got LOTS of it out there, might as well use it and keep people employed in the USA instead of in some sandy desert in the M.E.) And lastly the option I'd like is some type of small pellet nuclear based system. Now, don't freak... I'm sure some bright engineer out there would figure out a way that it could be done. Think about it, you'd buy a years supply of fuel in one tennis ball sized container. Something like a Mr. Fusion would be a plus, but "Big Oil" has been supressing that Tech since 1984.

Re:Stirling sinks, give me these three instead: (1)

JoeMerchant (803320) | more than 5 years ago | (#25698881)

According to my Thermodynamics professor, big heavy Sterling engines can be more efficient than internal combustion, but as of 1985 they hadn't managed to make them efficient ones enough to fit into "normal" vehicles.

Stirling Engine (3, Funny)

cwsulliv (522390) | more than 5 years ago | (#25698623)

The Stirling engine is pretty neat. It'll run on hot air.

If we install a bunch of them in Washington DC, the energy problem of the US will be solved for good.

Would be better with a Carnot Engine (1)

n2rjt (88804) | more than 5 years ago | (#25698775)

I see two classes of criticisms, both quite valid, but neither distracting from the beauty of the idea.

First, the Ford Think wasn't well-thought. 0-30 in 6.5 seconds, with an electric motor? Excuse me?!?
Second, nobody can explain why the Stirling Engine was chosen for this prototype, when many more efficient choices seem to be available.

Nevertheless, the idea is solid. Let's have a hybrid that's basically an electric with fuel assist. Like the Aptera, but perhaps sacrificing a bit of efficiency for more conventional looks.

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>