Dean Kamen Combines Stirling Engine With Electric Car

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.

Comments

stirling engine is a no-go

[Ancient_Hacker]

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

[OrangeTide]

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

[raynet]

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

[shbazjinkens]

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.

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

[CubicleView]

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

[rolfwind]

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

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

[Anonymous Coward]

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

[ScrewMaster]

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

You mean like this one?

Re:stirling engine is a no-go

[rolfwind]

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

[maxume]

Doble steamers were way nicer:

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

The biggest difference was a condenser.

Re:stirling engine is a no-go

[jacquesm]

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

Re:stirling engine is a no-go

[morgan_greywolf]

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

[MechaStreisand]

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

[ChrisMaple]

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

[JoeMerchant]

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

[JanneM]

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

Re:stirling engine is a no-go

[itzdandy]

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.

Re:stirling engine is a no-go

[Anonymous Coward]

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.

Re:stirling engine is a no-go

[fyrewulff]

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

[Anonymous Coward]

I drove a Celebrity and there is no way that thing got 40 mpg on the highway. If I gunned it to pass someone I could actually see the fuel needle drop slightly.

Re:stirling engine is a no-go

[Anonymous Coward]

Yes, but 6.5 seconds IS flooring it.

Re:stirling engine is a no-go

[EaglemanBSA]

It is indeed the most efficient thermal engine we know of. Whoever said they're terrible in terms of efficiency is, for the most part, incorrect. They're difficult to implement because of the extremely tight tolerances needed to maintain such high efficiency, but you can achieve efficiencies at least as good as or better than a typical car engine (28% is usual for the car, 35-40% is easily achieved with a stirling engine, depending on the operating points).

The problem isn't that they're difficult to get up tospeed, but rather that they tend to operate at a constant speed. This is related to the pressure inside the engine, so the only way to vary its natural operating speed is to add or remove pressure from the chamber. It was this added system that drove the Ford's engine to failure because of the extreme complexity needed to control the speed.

This engine does make an ideal charger. I'm excited to see the results in production.

Re:stirling engine is a no-go

[OrangeTide]

Well those aren't very modern. there are far more modern designs that can reclaim heat in a closed loop system. Of course if I would love to own a Stanley Steamer, just from the pure novelty (and history!) of it.

Green Stream Engine is a newer design and with the right condensers is very practical and can be built compact enough to fit inside an electric vehicle to complement the electric drive train. One could just run the steam engine at a fixed rate to constantly recharge a battery system, so that overall the generators will produce enough power to maintain a constant charge on the system. But short bursts of power that deplete the system more quickly can be used for acceleration. I believe that is the point of a hybrid electric.

Re:stirling engine is a no-go

[shbazjinkens]

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

According to NASA, there was no weight change. Read it. More expensive is a matter of mass production, no auto engine is exactly simple nowadays anyway.

Re:stirling engine is a no-go

[morgan_greywolf]

0-30 in 6.5 seconds is the MAXIMUM. Your average ordinary car can do that much, much quicker.

Re:stirling engine is a no-go

[Anonymous Coward]

Do you know what thermodynamics is?

Re:stirling engine is a no-go

[lysergic.acid]

i'm with you on that one. i much prefer this kind hybrid electric than the drivetrain-based hybrids (whether full hybrid, mild hybrid, power assist hybrid, or mild hybrid).

a full hybrid is not bad, since it is capable of running on just the electric motor, but i think adding the gas engine as a secondary power source (charging the battery, heating, etc.) on a plug-in electric would move us away from a petroleum-economy faster.

this way, we can still free ourselves from our oil-dependency gradually, but we'd already have the transportation infrastructure in place for alternative fuels. that's because plug-in electrics are basically fuel source neutral. you can get your electricity from a coal-burning power plant (that's still exponentially more efficient that having millions of ICE vehicles on the road), or you could get it from solar power plants which are becoming increasingly popular, or you could get your power from nuclear power plants. heck, a plug-in electric is even future-proof since you can power your car from energy sources that have yet been invented. electric vehicles basically make the "which fuel is better" debate moot in terms of vehicle propulsion.

it's a lot easier to upgrade a single power plant than it is to replace thousands of private vehicles. and all the advances being made in alternative/clean energy right now--like solar thermal energy, tidal power, wind farms, etc.--can't be taken advantage of until we have plug-in electrics on the road.

Re:stirling engine is a no-go

[lysergic.acid]

well, Stirling engines seem to work well enough that they're used in a lot of CST (Concentrating Solar Thermal) plants. i think most parabolic trough and solar power tower installations use Stirling engines to generate electricity.

Re:stirling engine is a no-go

[HangingChad]

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.

I wondered about that, too. Had thought about a kit conversion for a DIY electric car and wondered about putting one of those quiet Honda generators in it to charge the batteries while it's sitting in the parking lot. Why wouldn't that work? I don't think there would be enough current to drive the car, but three or four hours would put a lot of charge in the batteries.

Those little Honda 1000's will run for hours on a gallon of gas. 1000 watts will put some charge in a battery.

You'd think if it was that simple someone would have thought of it.

Re:stirling engine is a no-go

[Anonymous Coward]

Stirling engines are routinely used in marine applications for electrical generators in pleasure craft. They're quiet, make very good use of the heat sink (the ocean), and it's an application where you just want it to chug away at fairly constant revs.

So to say they're not in use everywhere, more like nowhere, is like, wrong.

Re:stirling engine is a no-go

[Anonymous Coward]

I got about 30-35 highway actual MPG in mine (automatic) and the way they test it inflates the efficiency (no wind resistance). Also, like 3/4 of the weight of that car was in the engine. Unless the sterling engine was made out of cast iron they probably saved a thousand pounds.

The Celebrity was actually a pretty fun car. Driving around in a POS with 50-year-old-looking paint kinda made people get out of your way.

Re:stirling engine is a no-go

[cayenne8]

Regardless of the efficiency of the engine used...this stat here:

"Some stats on the Ford Think: Top speed, 55mph; 0-30, 6.5 seconds"

Is what I would think would kill the car as a practical use vehicle. Anywhere I've lived, that slowness would get you killed on any road, and I'm talking even city streets....let's not even mention the highway where if you didn't get run over by traffic, someone would eventually shoot your ass for holding things up!!

Re:stirling engine is a no-go

[fractoid]

I should move to where you live. Here (Perth, Australia) the government's spent the last 20 years and millions of dollars trying to brainwash the locals into believing that travelling 5km/h faster than any arbitrary speed (I'm serious, one of the latest campaigns has the catchphrase "drop 5, save lives" meaning "travel 5km/h below the speed limit so you don't have to look where you're going or in fact be able to drive a motor vehicle at all".)

Public roads where I can shoot people for being terminally slow? Please yes!

Re:stirling engine is a no-go

[Derek Loev]

What about making left turns? Seems like it would take forever to find a sufficient gap between cars. And that's not just an inconvenience, it's also a safety hazard.

Re:stirling engine is a no-go

[hldn]

if you're too scared to make a left turn, go an extra block up and make three right turns.

Re:stirling engine is a no-go

[blueZ3]

Generators sold to consumers do not need to meet the strict exhaust regulations the government imposes on passenger vehicle engines. If you do a power-to-power comparison between (for instance) a Honda 1000 and a Honda Accord, you'll find that the generator produces significantly more pollutants than the car. I'm curious to see how Aptera is going to get around this when they have to get their car to pass CARB's tests.

This is why it's not done commercially--though your retrofit idea would work.

Re:stirling engine is a no-go

[OrangeTide]

If you have plenty of low end torque to get up the hills, 0-30 in 6.5 seconds would be fine for most of San Francisco.

Re:stirling engine is a no-go

[Anonymous Coward]

Once purchased does it require any more energy input from you to do work? No. Seems alot like free to me.

I see someone like you in every conversation about stirling engines, solar, or wind power.

'oh its not efficient'.

What the fuck is wrong with you people? Honestly. Are you paid to crap on everything? Or is it just natural?

Free is still free. does waste heat, solar, or wind cost you anything for the input energy required to get work done? nope. Sure seems like a great deal to me. efficient or not. You're getting something for nothing.

The only real question that should be asked is 'does the system ever pay for itself?'.

And so far the answer is always yes.

But yet we dont seem to be moving to these technologys very quick at all. Thanks guys. Your negativity has costed the world billions.

Every power plant in the world should have a stirling engine using the wasted heat from the plant to generate a little more electricity. It would pay for itself. It requires input that we are currently throwing away. How efficient is just dumping that heat to the air? If we can get even another .5% out of it. Its worth it.

Stop being so negative when the input didnt cost us shit. You're holding the world back.

Re:stirling engine is a no-go

[JesseL]

Unfortunately theory runs into problems when you start trying to actually source things like ideal gasses, perfect insulators, and materials with zero thermal mass.

Re:stirling engine is a no-go

[Anonymous Coward]

Look, it's an engine, it's not magical. The efficiency depends on whether the engine is starting, has been running, has been tricked out with hydrogen gas lines by NASA engineers, etc.

That document you linked to lists 38.5% as the maximum efficiency, with the startup of the motor being 10% efficient. (Why rip the grandparent, but not post these numbers? Your comment about combining with electric engines doesn't make sense without them.)

I do wonder what a team of NASA engineers working for several years and using the best materials would have been able to do with an internal combustion engine. Sure, NASA made something their engineers claim was cheaper and better than a regular motor, but there's some reason (hot hydrogen gas? an overlooked flaw?) that no one picked it up. My bet is that it was the startup speed (20 to 30 seconds to get going!) and startup efficiency.

Re:stirling engine is a no-go

[lazybeam]

5km/hr? Here (Queensland) it's "one", with the slogan "Every k over is a killer". And they put speed traps where you are going down a hill where the speed limit changes from 70 to 60 on a big wide road... *grumble*

Re:stirling engine is a no-go

[Anonymous Coward]

Yeah, he probably does. Do you? The Stirling cycle is theoretically the most thermodynamically efficient heat engine cycle we know of. The problem is the difference between theory and practice.

Re:stirling engine is a no-go

[Anonymous Coward]

And if you run it in reverse you have a great heat pump, often used in cryocooling etc.

So instead of backing into a parking space you freeze solid in the middle of the road??? No thanks!!!

Re:stirling engine is a no-go

[ppanon]

Heh, oops, Of course, it's the Carnot cycle that's theoretically the most efficient thermodynamic heat cycle.

Re:stirling engine is a no-go

[ppanon]

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.

A Stirling engine is an external combustion engine. It generates waste heat as a byproduct of operation just like an internal combustion engine does. That allows the heat to be used for the defroster and heater. But it's primary function is no more to generate heat than it is with the engine in your car. However, unlike an internal combustion engine that requires fuel that can undergo controlled explosion, the stirling engine just requires a source of sufficiently high heat (efficiency of the stirling cycle is related to the difference in temperature between heat source and sink).

Re:stirling engine is a no-go

[Anonymous Coward]

"the only way to vary its natural operating speed is to add or remove pressure from the chamber"

Wait, isn't this the perfect place for "Continuously Variable Transmission" to be used?

Re:stirling engine is a no-go

[mrchaotica]

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)

Speaking of Civics, did you know that yours has plenty more engine than it needs too? A decade or so ago, Civics had engines with 70-90 HP. It seems silly to me that everybody thinks efficiency in the 40-50 MPG range is so hard that it requires electric motors and stirling engines and whatnot, when a perfectly normal CRX HF -- the cheapest CRX -- did 45 MPG in 1988! And that's the revised figure; according to the old EPA method the combined efficiency was 54 MPG.

Re:stirling engine is a no-go

[moosesocks]

If said wheelchair is your only hope of mobility, virtually any price is "affordable."

Re:stirling engine is a no-go

[Ex-MislTech]

Call them up on the phone and tell these guys their system
is not working like you said it should, and perhaps they
will make it suck like you say it should.

We can't have these ppl making this bad tech work
contrary to your obviously superior knowledge.

http://en.wikipedia.org/wiki/Stirling_Energy_Systems

Re:stirling engine is a no-go

[Ex-MislTech]

Some ppl seem to have a clue when it comes to Stirling Engines:

http://en.wikipedia.org/wiki/Stirling_Energy_Systems

Re:stirling engine is a no-go

[hachi-control]

And if you're flooring it every time the light hits green, you're probably not intending to be efficient.

Re:stirling engine is a no-go

[PerMolestiasEruditio]

Ideal stirling engines have Carnot efficiency, =(T_h-T_l)/T_h ie for 1000K hot end and 300K cold end that is 70% efficiency. However in practice gas and mechanical friction and other losses drop this massively and in practice 10-15% is typical, 20% is good and 35% is fantastic. T_h is severely limited by materials, 1100K is about it. and T_l is hard to get lower than about 50K above ambient.

For high efficiency you need to use high pressure hydrogen as a working fluid to reduce losses. But hydrogen makes for difficult design, embrittles many metals and leaks away over time.

Using burners also inevitably drops your efficiency as you throw some heat energy away in the exhaust.

Lubrication is a big problem. You can't use oil to lubricate pistons as oil vapour will gradually decompose on hot heat exchange surfaces screwing up heat and gas transfer.

I've had direct experience of Stirling engines for the last 25 years and outside of a few niches like maybe solar thermal, quiet running submarines and novelty items they are a stupid idea. IC engines are lighter, cheaper, more compact, more powerful, have higher efficiency and similar or superior longevity. They also avoid the need for complex and expensive heat exchangers.

With a bit of effort IC engines can also work with basically any combustible fuel (including wood and coal).

Re:stirling engine is a no-go

[Anonymous Coward]

Does that suggest that they would work better in the winter?

_AC

Re:stirling engine is a no-go

[Anonymous Coward]

Only if the hot side was well insulated enough that the outside temperature didn't affect it the same amount.

Re:stirling engine is a no-go

[jabuzz]

Why bother with a piston steam engine, when a turbine is way more efficient.

Once you have decoupled the power generation from the drive using electricity and placed some batteries or other electrical storage in between you have overcome the main limitation of turbines that they don't rev well.

You have also overcome the main limitation of steam, then need to get a head of steam up before you can move.

Re:stirling engine is a no-go

[EaglemanBSA]

Yes. I'm developing one for that specific purpose.

Re:stirling engine is a no-go

[Anonymous Coward]

Sorry, you are wrong. Sweden uses a submarine that has an sterling engine. It is effektiv and silent.

For this, the US rented one of the submarines(with crew) for around 2 years. This because the uses needed to bost it anti-submarine capacity.

Re:stirling engine is a no-go

[Anonymous Coward]

It's free except for all the added weight and cost of the parts of the setup.

Re:stirling engine is a no-go

[drinkypoo]

Anywhere I've lived, that slowness would get you killed on any road, and I'm talking even city streets...

In the city of San Francisco, aside from taking the freeway it is never practical to go more than 55 mph - and even then you will often not be able to go any faster there either.

In the city of Los Angeles, such a car would almost certainly get you killed.

Regardless, there is substantial use for such a vehicle. I'm in Santa Cruz (my birthplace) right now, and it would be ideal here too.

Re:stirling engine is a no-go

[drinkypoo]

What I want to know is, how do we get the plans for the engine? If my tax money designed that thing, how on earth can it be justified to keep that information from me? Incidentally, hybrids are an incredibly retarded boondoggle. A Diesel Rabbit, a CRX HF, and a Jetta TDI (note how two of these are VWs?) all get SUBSTANTIALLY better real-world mileage than any hybrid available in the US Domestic Market.

Re:stirling engine is a no-go

[drinkypoo]

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.

This is not a new idea, it's known as a "series hybrid". The approach has been used without batteries for many many years in your typical diesel locomotive, which is actually a diesel-electric system. Modern trains weigh too much to use a drivetrain. Sometimes small "pusher" engines are direct-diesel, but they just as often run on gasoline (better power to weight ratio since you can reasonably run higher RPMs on spark ignition than on compression ignition.)

The major benefit of this approach is that you can eliminate the transmission. Any design in which this is not done is stupid.

The other major benefit is that there is no reason to use an internal combustion engine! You could as easily use a turbine, which Chrysler had working for automotive purposes in the sixties. They had to let it go because their system destroyed transmissions. In a system in which a generator is integrated into the turbine and the transmission is eliminated, this problem is eliminated - and turbines have the additional advantage that they pair well with generators, which work best at high RPMs.

Re:stirling engine is a no-go

[fast turtle]

I've got a 1968 VW Bettle with a 1971 Dual Port 63HP engine. I'm considering converting to a hybrid setup using a 5-10 HP diesel to run a gen-set large enough to maintain speed and recharge small battery bank that's used for burst acceleration/starting.

Currently gets 38MPG and hybrid should at least double that to 76MPG and possible push 100+MPG depending on driving practice, which combined with 10Gal fuel capacity, provides a usable driving range

Re:stirling engine is a no-go

[Anonymous Coward]

all get SUBSTANTIALLY better real-world mileage than any hybrid available in the US Domestic Market.

You think diesel is expensive now? Just wait until everyone starts driving them AND the EPA tells the oil companies that they have to stop dumping their high-sulfur diesel in the US in order to stop the acid rain again.

Re:stirling engine is a no-go

[sunking2]

That's the problem with Kaman. When you make your millions off of medical devices its hard to remember what realistic for the rest of the people means. Its also the problem with the medical industry, $20k for a wheelchair. Everyone who comes up with a new bed pan wants $5000 a piece for them, and lord knows you don't want to be the hospital with one of the old ones.

Re:stirling engine is a no-go

[internerdj]

It must be amazing to lived in a planned city. Here, going up a block might mean you could never get back to your intended route. Ok, a bit of an exageration but still it may mean a huge detour. Here, the city has grown to the existing roads and now it is too expensive to start demolishing and make things better. Actually it is hard enough to get money to fund the needed expansions to roads where there are room for expansion.

Re:stirling engine is a no-go

[Dun Malg]

"having a car requiring a large gap in traffic to make a left turn safely" != "fear"

idiot

Re:stirling engine is a no-go

[Gilmoure]

A new efficiency record was set with a solar-to-grid sterling engine setup (page 6).

The award recognizes a solar-to-grid system conversion
efficiency record set by SES Serial #3 solar
dish Stirling system in January 2008 at Sandiaâ(TM)s
National Solar Thermal Test Facility. The existing
1984 record of 29.4 percent was toppled by the new
31.25 percent net efficiency record.

The conversion efficiency is calculated by measuring
the net energy delivered to the grid and dividing
it by the solar energy hitting the dish mirrors.

Now, whether sterling engines carry over to vehicles, yeah, that's another thing.

Re:stirling engine is a no-go

[shbazjinkens]

What I want to know is, how do we get the plans for the engine? If my tax money designed that thing, how on earth can it be justified to keep that information from me?

The reason I found that article was because I was seeking plans. What I found was that some of the major documents (like the summary I posted) have been scanned and are available online, but most of the technical documents are in their paper library. You have to buy them for something like $60 apiece (can't remember exactly the cost).

It is all there though.. for those who want to invest in the paper weight. This page will get you most of the Stirling results and this is the main document research website for NASA.

Re:stirling engine is a no-go

[genner]

I look forward to driving in front of you in the passing lane.

Re:stirling engine is a no-go

[ElizabethGreene]

you must be from new jersey. :)

Re:stirling engine is a no-go

[Dan Ost]

i think most parabolic trough and solar power tower installations use Stirling engines to generate electricity.

I think this is wrong. Except for the SES systems, most CST systems use a heat exchanger and a boiler.

Re:stirling engine is a no-go

[FiloEleven]

But that was twenty years ago. We're much smarter now~

Re:stirling engine is a no-go

[Anonymous Coward]

Well, the really sick part is that he's right - $20K is an awesome value for the service he's providing, in fact, if every wheelchair in the country were replaced with his $20K wheelchair, the country as a whole could save millions (net, after purchasing chairs) simply by revising the ADA building codes to accommodate his chairs instead of the traditional wheels.

Sad fact is, the world doesn't spin that way - at least not within my lifetime. I'm sure there are a lot of "Joe the Builder"s out there who are glad that we still need to retrofit or design ramps onto all ADA compliant buildings...

Re:stirling engine is a no-go

[Kopiok]

Unless that 3% is worth the extra weight/cost.

Re:stirling engine is a no-go

[drinkypoo]

You think diesel is expensive now? Just wait until everyone starts driving them AND the EPA tells the oil companies that they have to stop dumping their high-sulfur diesel in the US in order to stop the acid rain again.

I live in California, where the diesel is all low-sulfur. I just saw biodiesel at USA gas (not a high-end chain or anything, but whatever) in Santa Cruz for $2.99. That's cheaper than I've ever seen it (not that I have a long association with the stuff, but there's numerous sources around where I live - which is no longer down here in the scruz.)

I would also like to point out that biodiesel from algae is an entirely viable fuel - at $3/gallon, using the technology of twenty years ago.

Re:stirling engine is a no-go

[a-zarkon!]

Well first you have to assume that the car is a sphere...

Re:stirling engine is a no-go

[Anonymous Coward]

Say you let it run for five hours, and it produces 1000 watts constantly for those five hours. That's 5 kilowatt hours of charge in the batteries.

The engine in my car, a Peugeot 206, produces 44 kilowatts at peak. Assuming it only needs 30% of that if you drive like an incredibly efficient old man, and that your electric car needs half that due to weight and less transmission losses, your electric car will consume about 7 watts. So you'll be able to drive it for less than an hour on five hours of charging.

Long story short: it's not that simple. People have thought of it, and it doesn't work.

Re:stirling engine is a no-go

[Anonymous Coward]

With ObamaCare, we all pay for it, so it is always affordable!

Re:stirling engine is a no-go

[Frank T. Lofaro Jr.]

There are a lot of dual cycle power plants that use gas to run a turbine, and then use the waste heat to make steam to run another turbine.

Re:stirling engine is a no-go

[Ex-MislTech]

I can't believe some morons modded the grand parent of this thread
+5 insightful, what a bunch of uneducated can't look it up
on Wikipedia sheep.

Re:stirling engine is a no-go

[OldManAndTheC]

I've often wondered if it would be cheaper to give every wheelchair-bound person one of Kamen's fancy IBOT stair-climbing chairs rather than install access ramps, elevators (right next to escalators), curb cuts in sidewalks, etc.

Re:stirling engine is a no-go

[operagost]

$5,000 for a bed pan? That pisses me off!

Re:stirling engine is a no-go

[operagost]

Almost no one wants or can use a two seater unless it's fast. Ironically-- since most HOV lanes require 3 occupants-- that old Civic will have to sit in traffic, never realizing its potential.

Re:stirling engine is a no-go

[turgid]

Is Queensland run by Boss Hogg by any chance?

Re:stirling engine is a no-go

[eliphalet]

Yes, but turbines are vastly expensive.

Re:stirling engine is a no-go

[Nimey]

That doesn't work on a busy 4-lane intersection with stop signs at only two of four points.

Re:stirling engine is a no-go

[mrchaotica]

The lanes around here in Atlanta -- for now -- only require two occupants.

Of course, what's stupid about HOV lanes is that they don't take actual vehicle efficiency into account: two people in a 15 MPG Suburban, or one person in a 25 MPG hybrid SUV, get to use the lane while one person in a 45 MPG CRX or 50 MPG TDI (diesel) Golf don't.

Re:stirling engine is a no-go

[toddestan]

The point of HOV lanes is to reduce congestion by removing vehicles from the road during rush hour by encouraging carpooling, rather than promoting fuel efficiency. So that's why a 15MPG SUV can use the HOV lane with 2 people in it, and a Golf can't if it has 1 person in it.

Re:stirling engine is a no-go

[cayenne8]

"I look forward to driving in front of you in the passing lane."

Yep, once again confirmed...no shortage of assholes in the world.

Re:stirling engine is a no-go

[Anonymous Coward]

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.

The efficiency of a Stirling engine, like any heat engine, depends on the temperature difference between the heat source and the heat sink. If you have only a low temperature difference, then you have low efficiency. More precisely, efficiency is a function of the ratio of the absolute temperatures. For more information, see http://en.wikipedia.org/wiki/Carnot_cycle

Re:stirling engine is a no-go

[mrchaotica]

The point of HOV lanes is to reduce congestion by removing vehicles from the road during rush hour by encouraging carpooling, rather than promoting fuel efficiency.

Oh yeah? Then why do people driving "alternative fuel" vehicles get to use it without passengers?

Re:stirling engine is a no-go

[endgas]

Sorry to get in late here but I'd like to get to the bottom of this Stirling engine conundrum. I'm always told the concept is theoretically efficient and the thermodynamics shows us why. But at the same time apparently, these engines can't be made to work in a more purposeful way than harnessing the heat loss from a cup of tea. Why?

Re:stirling engine is a no-go

[Anonymous Coward]

You realize that Dean didn't set the price, right? It is sold by Independence Technology, a division of J&J.

Re:stirling engine is a no-go

[JoeMerchant]

I think Kamen is fascinated with the Sterling simply because it is theoretically the most efficient thermal cycle. He believes that his demiGod engineering and development abilities can realize a significant portion of that theoretical efficiency in a small package.

He has been developing the concept for a long time, I believe his current versions are quite a bit better than 6% efficient.

Re:stirling engine is a no-go

[JoeMerchant]

What city do you live in? In most larger ones I have driven in, all the econoboxes do just that (full throttle acceleration from every light.)

Re:stirling engine is a no-go

[Ancient_Hacker]

A single example of a govt-subsidized one-off experiment that has not been running for very long is a mighty poor flagship example.

When you can point to a Stirling engine that has been running for a year or two with minimal maintenance and is economical compared to the many proven alternatives, then we can talk.

Re:stirling engine is a no-go

[Ancient_Hacker]

Ah, no. The temp difference sets an UPPER LIMIT to the efficiency. There is no limit to how bad it can be. And a Stirling engine tends to be really poor as you need unobtainables such as perfect insulators with high thermal conductivity.

Re:stirling engine is a no-go

[Ancient_Hacker]

So for some reason all these guys are getting terrific efficiency from their Stirling engines but everybody is being really shy and coy and squeamish about even hinting as to the efficiency they're getting. Use some common sense, people. The Stirling engine has been the next big thing for 160 years, and may very well continue to be that for just as long into the future.

Re:stirling engine is a no-go

[JoeMerchant]

I'll buy it when they produce one... I'd really like to have something quieter than my Honda gas generator, no, I haven't seen one yet. That doesn't mean it's impossible, just not practical in today's industrial framework. I'm not holding my breath waiting for it - I went ahead and bought a practical ICE based generator in the meantime.

Re:stirling engine is a no-go

[Ex-MislTech]

I guess they lied and the system is doomed to fail !

All that testing and research was all falsified !

Sorry to hear about your oil stock ancient one...

Disruptive technology

[Chairboy]

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

Great read, and the concepts are laid out here:

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

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

Re:Disruptive technology

[bug1]

he's referring to the concept of disruptive technology as written about in The Innovator's Dilemma by Christensen

Hmm, i thought disruptive technology was things the web 2.0 video commercials and spam. /sarcasm

Think CITY??

[caffeinemessiah]

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??

[Rei]

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??

[Anonymous Coward]

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??

[Rei]

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??

[Anonymous Coward]

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??

[smart.id]

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??

[Anonymous Coward]

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??

[Anonymous Coward]

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??

[ion.simon.c]

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

Re:Think CITY??

[Neoprofin]

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??

[JoeMerchant]

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

Re:Think CITY??

[Rei]

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??

[Rei]

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??

[JoeMerchant]

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??

[budgenator]

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??

[Rei]

Exactly. My spouse and I are getting an Aptera Typ-1e, and it'll be responsible for 95+% of our driving. We're going to keep my old Saturn around for those rare occasions where I need do so something unusual like pick up four people in Muscatine. We may end up using it so rarely that we may ultimately not bother putting it on our insurance policy, and instead just add a rider if we ever need to use it.

Speaking of insurance, I talked to someone with an NmG (a more primitive electric three wheeler), and with the NmG as his primary vehicle, his annual insurance is only $252. For an adult male in southern California with full comprehensive coverage from State Farm. ;). Gotta love "motorcycle" insurance rates! If the Aptera is built well, there should be almost no maintenance to go along with the dirt cheap insurance rates and the dirt-cheap electricity costs (at my rates, $1 for 120 miles)

Re:Think CITY??

[swillden]

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

I have a wife and four children and I want an Aptera. Sure, it won't work when the whole family is going somewhere, but neither does our normal four-door sedan (Saturn Ion II). But the Aptera will be a great car for commuting, running to the grocery store (which is 40 miles away) and lots of other running around.

When we all go somewhere together, we need a vehicle that seats six comfortably. For that (and for camping, boating, hauling stuff, etc.) we have a Dodge Durango.

Different vehicles for different purposes.

Re:Think CITY??

[WalksOnDirt]

There has been speculation that it's actually going to be front wheel(s) drive. That seems like an awfully big change this late in the game (unless it was a secret plan all along), but it might improve the ability to handle bad weather. It would also be a big enough secret to justify your NDA.

Re:Think CITY??

[zelik]

To be fair, that's actually fairly acceptable in countries outside of the USA/Europe (for example, I'm in Taipei, Taiwan and in this country you are lucky to exceed 110km/h on the freeway (68mph). In many cities I've been to, cars rarely exceel 50 km/h in the city and 0-50km/h (50km/h = 30mph). Add to the fact that many cities are loaded with speed cams and the expensive price of gas, this is a perfectly acceptable city car or taxi.

Re:Think CITY??

[GigaplexNZ]

I drive quite frequently and I am not a complete idiot. That said, I have never been in a snowstorm. Not everyone lives in the same climate.

Re:Think CITY??

[GigaplexNZ]

I think it might be tied to cookies or something like that. With the plethora of browsers out there, just open one as AC and logged in on another.

That said, what is the point in posting AC and moderating yourself up? You waste a mod point and don't get the karma. If the comment was worthy, it should be modded up by others naturally.

Re:Think CITY??

[Anonymous Coward]

Yeah, because the more traffic there is, the more you are able to accelerate.

Re:Think CITY??

[quenda]

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.

There are plenty or large cites, from London to Bankok, where drivers are grateful to reach 30mph ever.

Re:Think CITY??

[Anonymous Coward]

Availability: Norway now, Denmark starting 2009 (Th!nk City); only in California after production starts in late 2008 (Aptera); World wide order plans to make your own (XR3)

Re:Think CITY??

[Kjella]

Purchase price: $20-25k + $150-$200 per month battery rental (Th!nk City); $27k (Aptera)

Not according to this

Take the battery out of the equation, and Willums says he can sell the car for about $15,000 to $17,000 in the United States, with a "mobility fee" of $100 to $200 a month

Think City is already shipping in Norway, I don't think the Aptera is shipping yet. Plus, I'd suggest anyone interested take a good look at the pictures, the Think City looks like a small car, the Aptera... well, unconventional is probably the best word I got without getting nasty.

Re:Think CITY??

[illumin8]

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.

Every article that mentions electric cars, somebody brings up the Aptera. The reason why the Aptera is not really considered a likely candidate for mass transportation is that it's really just a motorcycle with a cage around it and wheels to balance it on the side. Most people would not consider this device to be safe enough to operate on a daily basis. Look it up, the only way they could get around the safety regulations in California is by classifying it as a motorcycle and not a car.

It still looks like an innovative design, but I wouldn't want to get in a wreck in one of them.

Re:Think CITY??

[Rei]

Not according to this

That article is over a year old. If you took information that out of date about the Aptera, you'd come out with its price being $20,000.

Think City is already shipping in Norway, I don't think the Aptera is shipping yet.

Correct. Aptera's target date is this December.

Plus, I'd suggest anyone interested take a good look at the pictures, the Think City looks like a small car, the Aptera... well, unconventional is probably the best word I got without getting nasty.

It's a "love it or hate it" car. About half the people I've seen comment on it think it's one of the most beautiful cars they've ever laid eyes on, and most of the rest think it's an abomination to the eyes. I've found a couple of neutral people, but not many. As for me, I find aerodynamic forms aesthetically pleasing and non-functional style elements (such as oversized grilles, spoilers, etc) dumb looking, so I think the Aptera is a beautiful bird indeed.

To people who go looking for Aptera pics, however: make sure you're looking at the Typ-1, Mk1 (or the Typ-2, as it may be now), and not the Mk0. The Mk0 was an early test vehicle. The Mk0 has dark side windows that are shaped like pine-cone scales against a "bent" A-pillar; small, bland inset headlights; an angular termination of the rear wheel skirt; and a rear end that tapers practically to a point (no tail lights, no license plate). Its wheel struts look bent when viewed from the front. It doesn't look nearly as nice as the Mk1 and beyond.

Re:Think CITY??

[Rei]

First off, I can't recommend strongly enough that you view the YouTube video of Chris hitting the shell with a hammer. It has over double the required roof and door crush strength for cars. It has not just an ordinary crumple zone, but an innovative crumple/deflection zone designed to help the vehicle ride up in an accident. It has full in-seatbelt curtain airbags. This is a vehicle that should blow most cars out of the water when it comes to safety. Secondly, as for handling, you need to read more about three wheelers; here's a primer. One wheel in front and two wheels back is notoriously unsafe and unstable, but two wheels forward and one wheel in back, with the CG just behind the front wheels, handles almost identically to a four wheel car, except that it has a faster response time. Basically, when you brake or steer, the CG slides up between the two front wheels, and thus has the same amount of resistance to flipping laterally that a four wheeler has. Also, they are naturally prone to understeer (like four wheelers), not oversteer (like tadpole three wheelers). About the only thing you wouldn't want to do in a tadpole three wheeler is something like a J-turn.

There are many reasons for going with three wheels. Yes, a big one is that it has a lot less certification that has to be done. But if they're voluntarily doing crash and crush tests, who cares? The other benefits are numerous; here's just a few. The ideal aerodynamic shape to enclose as much volume as possible with as little drag as possible is a stereotypical teardrop (or truncated teardrop); this means wider in the front than in the rear (hence, two wheels forward, one backward). Three wheels means you can elimiante an entire wheel. And all of the drivetrain/braking/cabling/wiring requirements that go along with it. Which reduces weight, purchase costs, and maintenance. And cutting weight means increasing range, and so on down the line.

Re:Think CITY??

[ptudor]

I don't have a wife or two small children; how can I get rid of those three extra seats in my VW GTI? Oh, by getting a single seat electric motorbike with better specs than the Think mentioned in the summary. Just because I'm not in a certain category doesn't exclude anyone else from being in that category.

If you want a serious answer, if it were ten years ago you could put them all in a RAV4 EV or a four-seater GM EV1. But there was "no demand" for electric vehicles since no one was allowed to buy them, with the idea today being let's all go buy "flex fuel" cars that keep the chains of petroleum intact and prevent a large scale migration to electric vehicles.

If I could trade-in my GTI for an Aptera, I would. No more oil changes, no more trips to the gas station, no more noise...

Re:Think CITY??

[JoeMerchant]

Sorry, just read up on the Aptera - it can't tow a trailer, so I guess taking the boat to the lake is also out....

Seriously, Aptera is a California only concept at the moment - nice concept, but it won't be killing the rest of the automotive market anytime soon. I also question their ability to deliver mass quantities of that body shell within their target price - maybe the passionate craftsmen they have right now can do it, but getting that produced en-masse will be a significant challenge. There's a reason the Corvette body never migrated down to the Camaro.

Re:Think CITY??

[JoeMerchant]

Or, just get two Apteraie and run a wireless video conference link.....

Re:Think CITY??

[swillden]

At most one of my kids is small enough to fit in the back, so we'd need three Apteras, and I'd have to let my son drive one of them. The result would still be more fuel-efficient than the Durango, but couldn't pull the boat, camp trailer, etc., and I don't know how well the Apteras would do off-road, so I think the Durango still has its place.

Re:Think CITY??

[JoeMerchant]

We have a Ram 1500 Quad Cab for similar reasons.... and to those who complain that 15MPG is a crime against nature, I say that $30K for a gas sipper alternative buys an awful lot of gas (and that gas sipper costs $30K mostly due to the energy required to build it)

Re:Think CITY??

[swillden]

Agreed. Although, actually, my Durango gets 24 MPG on the highway when I'm not towing. Still not great, but given that a minivan would only get us 27 or so, I feel pretty good about it.

Of course, when I hook the trailer on, that drops to about 9 MPG, and the 14 MPG I get towing the boat is more than offset by the gas the boat's big V8 sucks through its high-performance four-barrel carb -- but, hey, the reason we want to save the planet is so we can enjoy it, right?

*yawn*

[Anonymous Coward]

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*

[OrangeTide]

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*

[zappepcs]

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*

[Rei]

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*

[zappepcs]

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*

[Deadstick]

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

Re:*yawn*

[budgenator]

The stirling engine is just a bullshit PR stunt, it isn't doing anything that an off the shelf 5 KW Honda generator from a hardware store couldn't do better and cheaper. Remember these guys made the segway so PR stunts aren't foreign to them. Nothing like throwing in an exotic axillary power unit to draw attention from the fact that the primary drive unit's spec are at best mediocre

Re:*yawn*

[Kotukunui]

You do NOT need to drive a tank.

...unless everyone else IS driving a tank.

Re:*yawn*

[K. S. Kyosuke]

"Better" means "louder" (than a Stirling) and "requires one particular fuel" (unlike a Stirling)? There is nothing exotic on a Stirling. They've been here for almost two centuries and they make perfectly normal heat engines.

Re:*yawn*

[Anonymous Coward]

I don't get the same result, but my vehicle is designed to crumple up when it runs into an obstacle. Something to do with keeping me alive. I don't care if the car is totalled, as long as I'm not.

Re:*yawn*

[Rei]

Your roof is designed to crumple?

There's a difference between crumpling where designed to (which the Aptera does as well) and crumpling anywhere.

Re:*yawn*

[Anonymous Coward]

FAIL.

stirling engines are ridiculously safe.

We're talking about the safety of an entire vehicle. We're also talking about the Think City which has no Stirling engine.

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.

The engines would be cheaper if mass produced, but the overall cost of the vehicle wouldn't change a whole lot. You just can't take an underpowered engine and slap it in an existing vehicle. I'm betting you need a lighter vehicle just to get the pathetic performance they're offering. You can have a lighter vehicle, but up goes the price if you also want safety.

I just don't see these things being a whole lot cheaper than, say, a Geo Metro. And even compared to a Geo Metro these things are underpowered.

Re:*yawn*

[Dun Malg]

"requires one particular fuel" (unlike a Stirling)

This is true, but somewhat misleading. In theory, yes, you can run a stirling on any fuel; but in practice, your burner system is going to have to be designed for a certain type of fuel. You can't just put diesel oil or propane into a system designed for gasoline. At best you could probably use kerosene or alcohol. You're certainly not going to be able to shovel coal into a stirling made to run on CNG!

Re:*yawn*

[budgenator]

you can get multifuel diesels that will run on anything from bunker fuel to 104 AV Gas. Stirlings were fantastic engines back in the days when they used to make steam boilers out of pig iron; and are still great for many applications, I just don't see this as one of them

Wondering what a Stirling engine is?

[mgkimsal2]

Wonder no more

"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?

[Rei]

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?

[TheRealMindChild]

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.

Re:Wondering what a Stirling engine is?

[Rogerborg]

Ooh, the battery. What's that, a $7K item, and the failures start at 7 years (depending on your duty cycle)? Hands up anyone who would buy a 5+ year old hybrid with its original battery. Anyone? Anyone at all? You'll get a free bridge with it.

Re:Wondering what a Stirling engine is?

[Rei]

Amazing myth density there.

1. Hybrid batteries are engineered for 10+ years of operation.
2. As an example, Honda reported this summer that of 100,000 hybrids on the road, there have so far been only 200 out-of-warranty battery replacements. On Toyota's second gen Prius, they've had to replace 0.003% of its hybrid batteries out of warranty.
3. The batteries aren't $7k. Or anywhere close to that. Honda batteries are now down to $2k for the Insight, $2.5k for the Accord, and Toyota's Prius battery is $3k.
4. Hybrids have extremely high resale value. What *really* loses value fast are big SUVs. The Hummer H2, for example, costs 50% more than the Prius but loses value 3 times as fast. And that's the blue book; in the recent oil spike, hybrids were selling for well over blue book, while SUVs were selling well below. I assume that this situation has since been remedied.
5. Since this topic was originally EVs: EVs have even greater battery reliability, as their duty cycle is much gentler than that which hybrid batteries go through. 10-year-old RAV4EVs, for example, sell for $60k or so on Ebay.
6. To strike a final nail in this "all batteries must inherently have short lifespans" myth: Jay Leno sometimes drives around in a 1909 Baker Electric on its original batteries. The lifespan of a battery is deeply related to the stability of its chemistry. Some battery charge/discharge reactions aren't very reversible, while some are incredibly reversible.

Re:Wondering what a Stirling engine is?

[Anonymous Coward]

Actually GP is more correct.

1-2. Current priuses are from 2004. So it's not a very long track record - less than 5+ and for sure less than 7.

3. Well there is no market for them yet. But let say it is so.

4. Moot point because gp was talking about 5+ years old. Additionally by that time the hype will be over.

5. These are not high production volume cars. So ebay price is irrelevant.

And on top of that, gp mentioned magic words: "depending on your duty cycle". For example my daily commute is few low speed miles long - all "battery miles". I'll kill the pack in few short years but the odometer's value will be outstanding.

Re:Wondering what a Stirling engine is?

[Rei]

No, GGP is not.

1-2. I just gave statistics. The Honda Insight, for example, which falls under Honda's 100,000, was introduced in 1999. Honda has only had 200 out-of-warranty battery replacements.

3. That's the MSRP; what do you mean "there's no market"? If that's what the manufacturer charges, that's what it costs. If you were talking used batteries, those are generally under $1k.

4. The market disagrees with you.

5. Last year, just concerning the Toyota Prius alone, Toyota sold 181,221. And they're on track to beat that number this year. This is not a low-volume car.

Re:Wondering what a Stirling engine is?

[toddestan]

Ooh, the battery. What's that, a $7K item, and the failures start at 7 years (depending on your duty cycle)? Hands up anyone who would buy a 5+ year old hybrid with its original battery. Anyone? Anyone at all? You'll get a free bridge with it.

Well, you take your chances with a used car. Who would buy a 5+ year old car with an automatic transmission? The transmission could fail at any time and you could be out a similar amount of money as a new hybrid battery would cost (which is not $7k, by the way). Or a 4WD system, or xenon headlights, or any other big ticket item that can fail. Even if the battery was a given, the general reliability of most hybrids could still make the car a winner. And besides, I suspect that most hybrids would still drive with a bad battery anyway, though you would obviously take a significant hit to your mileage.

Diagram

[russoc4]

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

Re:Diagram

[Anonymous Coward]

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

Re:Diagram

[ScrewMaster]

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

[Arthur Grumbine]

From the Discussion page for that image:

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

Re:Diagram

[Anonymous Coward]

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

Re:Diagram

[Anonymous Coward]

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

Re:Diagram

[ScrewMaster]

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

[shut_up_man]

Viva vas deferens!

Re:Diagram

[TheLink]

O VRY?

Re:Diagram

[Anonymous Coward]

http://dilbertblog.typepad.com/the_dilbert_blog/2007/09/giant-penises-s.html

Wow. More of the same.

[schnikies79]

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.

Not fast enough

[MMC Monster]

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

[OrangeTide]

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

[Cyberax]

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.

Re:Not fast enough

[Anonymous Coward]

It's not that roads aren't designed for scooters, it's just that most drivers don't think to look for them. As the number of people that switch to scooters and motorbikes for economy increases, the accident rates will go down as people get used to being around them.

Re:Not fast enough

[Anonymous Coward]

If you like to get wet when it rains.

My 20 mile daily commute has a max speed limit of 45mph, I've looked at scooters, but I just can't justify spending $1000 for another vehicle when I'll end up getting wet coming home, cold going in in the morning, and sweating to death on days it doesn't rain.

Re:Not fast enough

[OrangeTide]

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

At least with a scooter you're not going to worry about dying from cancer.

Re:Not fast enough

[OrangeTide]

If you like to get wet when it rains.

Amazing invention, called a rainsuit. Fishermen have been wearing them for a century to keep warm and dry.

Re:Not fast enough

[Archimonde]

Most cities are just not planned for scooters

And Italian cities are planned for scooters? How? Have you seen how many scooters are there? Those cities have relatively narrow streets because most of them are pretty ancient. To many people over there scooter is the *main* vehicle they use.

Re:Not fast enough

[Anonymous Coward]

I live on an RV and drive all across the country. I do 55mph on the freeway and that is with 75 MPH speed limits. It is a symptom of the speeding up of everything (thinking, acting, working, eating, moving, etc) that is making drivers think they have to drive so fast. I drive 55 for many reasons including gas savings, safety concerns and to have more time to decide on traffic decisions.

To everyone else who thinks it is somehow "not safe" to drive slower, SLOW DOWN. Give yourself extra time to get to your destination instead of speeding along to get somewhere "faster". Many can not help but move fast. They think fast, act impulsively and do everything fast. This is naturally extended to the moving vehicle. Try consuming less sugar, high-fructose corn syrup and caffeine. Fast-moving television and movies have a negative influence on our whole "faster" way of life too. Someone even wrote a book on being faster. http://fasterbook.com/

This is why I live on the road. I don't have to *be* anywhere, anytime. I choose where I want to be *RIGHT NOW*.

And I'm 31 years old. I have a family to protect and care for.

Re:Not fast enough

[toddestan]

You would have to be crazy to drive a scooter in a lot of suburban areas in the US. The main drags are usually 45-55MPH, full of large vehicles, and are generally off-limits to pedestrians and bicycles, so people aren't used to seeing non-cars/trucks on them. This is different from Italy, where the streets are narrow which discourages fast speeds and large vehicles, and people are used to seeing pedestrians/bicycles/scooters.

Odd name

[Swizec]

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

[gyrogeerloose]

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...

[Sooner Boomer]

...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...

[klaun]

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...

[MartinSchou]

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...

[Rei]

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...

[Anonymous Coward]

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.

Re:Couple of things bother me...

[poopdeville]

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...

[apoc.famine]

Because if they don't have one, it makes them dependent on others when they need one. And there are many people who can't handle that.

A fair number of my co-workers are amazed that I'll drive a small car for my daily commute. When I ask they why they use a massive pickup truck as their commuter vehicle, it's "in case I need it", or some BS about not being able to afford a smaller commuter car while keeping their large truck. For them, knowing that they have a massive four-wheel drive truck at their disposal at all times is worth the cost.

For me, I make them feel good about themselves by asking to borrow it when I need a truck. Nothing is more manly than being able to help someone with your massive truck. It's the reason you bought it, right?

Re:Couple of things bother me...

[Max Littlemore]

I was agreeing with the mods, thinking you're just a Troll. Then I read this:

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.

You really haven't a fucking clue, have you? So I'm assuming you really are just ignorant. I won't bother posting links that others have already posted above, but I will try to help you to get a little educated: Stirling engines have pistons and external combustion engines are significantly easier to make clean than internal combustion.

Re:Couple of things bother me...

[bill_mcgonigle]

I beat the hell out of the body of my truck for the work I do with it (anybody have advice on a full-body bedliner sprayjob?). That might be one reason not to rent.

Of course, I also use mine to plow six months of the year, but that's not what you were talking about.

Re:Couple of things bother me...

[TheLink]

That sort of resource sharing was pretty useful in the "village" days. Very limited resources, if not enough people were willing to work together, everyone was in big trouble.

If someone could work out a way to reduce the impact of assholes/crooks, it may well be that lot more people might be willing to share (lend) their massive trucks or other resources.

Currently there seems to be some progress in the "giving" of resources no longer used with stuff like: Freecycle- http://www.freecycle.org/

Lending seems a bit trickier.

Re:Couple of things bother me...

[Sooner Boomer]

"Ah, yes, the horrors of a car that won't fulfill EVERYONES needs."

Oh noes, the horror of a car that doesn't fulfill MY needs because *I* won't buy one. And I don't have the money, and am not going to fall into the trap of getting a loan to buy more than one car.

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

And monkeys will fly out of my butt when people like me spend money on cars they can't drive.

Re:Couple of things bother me...

[Sooner Boomer]

"I will try to help you to get a little educated: Stirling engines have pistons..."

No shit Sherlock. And how many sparkplugs do they have. Try re-reading my post again and buy a clue if you don't find one there.

"...external combustion engines are significantly easier to make clean than internal combustion".

You're kidding, right? How are you going to control soot and particulate creation, much less conlrol them in emissions, in an automobile? We've been dealing with these with a degree (some say small) of effectiveness as well as NCG emissions for almost 40 years now in *internal combustion* engines.

Re:Couple of things bother me...

[MartinSchou]

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.

I said flat out. Top Gear did a race with five super cars (Lamborghini Murchiolago, Mercedes McLaren, Audi R8, Ferrari 599, Aston Martin DBS) where they filled each one with exactly 1 gallon of gas, and they'd be raced around their test track. The Ferrari sputtered to a halt as the first car after 1.7 miles. This was followed shortly thereafter by the Aston Martin and the Mercedes. The Lamborghini did 4.7 miles.

The Audi won the "endurance race" at 5 miles/gallon.

But you're right. Noone would ever want to buy a Ferrari 599.

Re:Couple of things bother me...

[Anonymous Coward]

Burning clean is easy in a external combustion engine like this because the temperature and burn time can be controlled. For example, the stove in my kitchen burns cleanly enough that I don't need a special exhaust system for it. ICEs have problems with this because they have to get the energy from the fuel and then exhaust it in the time it takes the piston to cycle. That means that they may burn too hot or too cold, and they almost always have some unburned fuel that gets exhausted.

Obviously it can only be as clean as the fuel allows. If you are burning a high-sulfur Diesel fuel, there will be sulfur emissions. Most fuels (kerosene, natural gas, gasoline, propane, butane, etc.) can be fairly clean, though.

dom

Re:Couple of things bother me...

[Anonymous Coward]

its main selling point is the no-emissions electric power.

Because as everyone knows, all electric power is generated for free with no emissions by the magic electric pixies. Sheesh.

Re:Couple of things bother me...

[Anonymous Coward]

The want the truck because they are morons.

Re:Couple of things bother me...

[toddestan]

For me, I make them feel good about themselves by asking to borrow it when I need a truck. Nothing is more manly than being able to help someone with your massive truck. It's the reason you bought it, right?

I've wondered if I should buy a truck for that reason. With everyone looking to downsize, I could end up being "the guy with a truck" for a lot of people. I figure when they borrow it, if I ask them to put some fuel in it, most people would consider that fair. Since I hardly drive, if I do this right I could have everyone else buying my fuel for me. Plus I would have a truck when I need it for something.

Re:Couple of things bother me...

[Anonymous Coward]

Average F1 fuel consumption is 3.1 mpg. That's more than FIFTY PERCENT more efficient than your figures. That is at 900+ horsepower, at 18,000 RPM.

"Top Gear" must have shite drivers.

Re:Wow. More of the same.

[ScrewMaster]

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.

Thermodynamics 101

[GrahamCox]

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

[Rei]

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

[theapeman]

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

[JoeMerchant]

Dean has a soft spot for Sterlings.

Re:Thermodynamics 101

[evanbd]

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.

Re:Thermodynamics 101

[budgenator]

a comparison to diesel-electric locomotive engines might be more realistic than buses and semi tractors.

Re:Thermodynamics 101

[Alastor187]

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.

The point you make is spot on. However, why isn't more effort put into continuously/infinitely variable transmissions. Generally speaking the operating range of the engine is inversely proportional the number of gears in the transmission. The less gears the wider the engine operating range, the more gears the smaller the operating range.

With enough gears one can choose the operating speed independently of the actual road speed. In such a case wouldn't the engine be able to operate at the peak efficiency for any given engine load?

Re:Thermodynamics 101

[Alastor187]

Sorry should have been formatted:

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.

The point you make is spot on. However, why isn't more effort put into continuously/infinitely variable transmissions. Generally speaking the operating range of the engine is inversely proportional the number of gears in the transmission. The less gears the wider the engine operating range, the more gears the smaller the operating range.

With enough gears one can choose the operating speed independently of the actual road speed. In such a case wouldn't the engine be able to operate at the peak efficiency for any given engine load?

Re:Thermodynamics 101

[Rei]

Efficiency is defined by energy out over energy in, or power out over power in as the case may be. Power is the product of engine speed and torque. So, yes, with a CVT, you can pick the engine speed that's most efficient for given power output requirements, trading engine speed for torque. However, that's the most efficient speed *for the given power requirements*. That doesn't mean that the current power requirements are the most optimal for the engine.

But yes, I think the poster's point was a good one, that in a series hybrid, you can run an engine at near optimum performance -- not by merely picking an optimal speed, but an optimal speed * torque as well.

Re:Thermodynamics 101

[tfoss]

Why don't the inventors of these various electric cars do some basic sums?

So the options are: 1. Some half-assed write-up in a local newspaper provides enough details that a random slashbot can accurately determine the critical flaw in the plan, and Dean frickin' Kamen is such an idiot he "can't do basic sums" or hasn't thought of the advantages and drawbacks of various engineering decisions that are apparent to a (presumable) novice, or 2. Perhaps there is more to consider than the fact that one type of engine is currently the most efficient.

Personally, I'm willing to give the benefit of the doubt to Kamen.

-Ted

Re:Thermodynamics 101

[GrahamCox]

However, why isn't more effort put into continuously/infinitely variable transmissions

The car/truck industry has attempted to make these work for decades with varying degrees of success. The fundamental issue is why you *need* a transmission at all. That tells me that there's something basically wrong with the internal combustion engine as a source of motive power. Indeed there is - it is just not really suitable because of the 'impedance mismatch' between the mechanical power it produces and that needed for a car in ordinary use. Therefore you need a clutch to overcome the fact that it cannot run at 0rpm, and gives barely any torque at all at idle speed, and it needs gears to overcome the limited speed range. It's also a one-way energy conversion system, so once it has converted to mechanical motion, it's gone - when you brake you simply throw the excess energy away (what's left after the transmission has thrown another third away before it even gets to the wheels). Looked at this way the I/C engine powered car is as wasteful as it gets. An electric motor on the other hand, has none of these problems. It gives plenty of torque at 0rpm (no clutch required) and a wide speed range (no gears required) and is a bidirectional converter (no brakes required, or at least most of the energy embodied in the moving vehicle can be recovered). Electric motors do away with the whole question of infinitely variable transmission, and all that weight saved translates into a potentially much lighter vehicle too.

I believe the short/medium term future for hybrid vehicles is an all-electric drive system using enough on-board battery (or supercapacitor) storage for a typical commute, plug-in-able, with an efficient fixed speed diesel-electric generator system to supply the power for longer trips. Current approaches such as the Prius are a joke - a mere tiptoe in the water - still far too complicated and hampered by the mechanical connection of the I/C component to the wheels. Trouble is most of the big car manufacturers are too wedded to their traditional mechanical thinking so far to make the leap, but there are signs that things are moving that way: the QED Mini, the Lightning GT and even the Chevy Volt. This car is actually thinking along the right lines, my only beef is with the Stirling-electric generator, which might look efficient on paper but I'm sceptical that it can be made to work in real life. At least a diesel is tried-and-tested, with loads of accumulated experience out there that can be tapped. If something better comes along then it could be swapped in without having to redesign the rest of the vehicle.

Re:Thermodynamics 101

[blueZ3]

The issue is energy denisty. Gasoline is currently about 15 times more efficient (by weight) than the best battery technology available. In other words, a pound of gas will take you 15 times further than a fully charged pound of batteries.

Nobody cares about how efficient your regenerative braking is, because it's never going to be all that high (there are too many other factors involved--friction, air resistance, etc--for it to approach double digits). And the "loss" you're talking about in the clutch/transmission system is already accounted for in the 15:1 ratio mentioned above.

What is needed for electric to really take off is a breakthrough in battery technology. Until batteries approach the energy density of fossil fuels, gasoline is going to be #1.

Re:Thermodynamics 101

[GrahamCox]

It's taken as read that the energy density problem is yet to be solved. That's why we are discussing hybrids and not pure electric vehicles. So given that you start with a tank of volatile petrochemicals as your primary energy store, what's the best way to maximise *overall* efficiency? Answer - convert to electric power as early as possible in the energy transfer chain and throw as little away as possible from then on. That means:

a) Use the most efficient thermal engine you can to drive a generator - right now that's a diesel optimised to run at a particular constant speed. Maybe something else might come along more efficient - Stirling maybe, if it has the same degree of research put into it that diesels have received in the past century.

b) Use motors at 80-90% constant efficiency for mechanical motive power with no further losses due to transmission (motor-in-wheel for example).

c) Recover as much energy as you can from braking. Since the energy cannot be converted back to petrochemical form, you need some form of charge storage.

d) Save as much weight as possible and make the vehicle as aerodynamic as possible within the constraints of it having to actually be useful, i.e. carry human beings and some cargo.

Re:Thermodynamics 101

[Rogerborg]

An appeal to authority? That's how your hero, Hitler, used to argue.

Re:Thermodynamics 101

[Anonymous Coward]

I believe the short/medium term future for hybrid vehicles is an all-electric drive system using enough on-board battery (or supercapacitor) storage for a typical commute, plug-in-able, with an efficient fixed speed diesel-electric generator system to supply the power for longer trips

Agreed, although I don't know much about combustion engines to give an informed response. For the long-term future, I'm actually expecting to see multi-actuator engines considering the compactness of an electromotor, i.e. one engine per driving wheel. Among other things, it would allow for controlled variation of wheel speed in turns.

Any thoughts?

Re:Thermodynamics 101

[tfoss]

Godwin's Law, you lose.

-Ted

Re:Thermodynamics 101

[Rei]

The energy density issue is very misleading.

Re:Thermodynamics 101

[bar-agent]

An appeal to authority? That's how your hero, Hitler, used to argue.

Hm. Actually, I think he argued using demagoguery and prejudicial rhetoric, not to his own innate authority. That got him authority, but I doubt his speeches went "hey, trust me, I'm the boss and I know stuff."

The Uri Geller of industry

[gilgongo]

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

[abigor]

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

[nate_in_ME]

Not to mention his "invention" 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

[abigor]

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?

Re:The Uri Geller of industry

[harmanjd]

Thanks for posting about that group. Looks very interesting.

Re:The Uri Geller of industry

[Concerned Onlooker]

Let's not forget he is also the founder of the FIRST Robotics competition. I'd say he's trying to change our world.

Re:The Uri Geller of industry

[bennomatic]

Don't forget the water purifier. Kamen went on Colbert and showed off a system that can extract pure water out of essentially any stew, and is robust and cheap enough to use reliably and distribute throughout the the third world. His demonstration was pulling good water out of, I don't know, raw sewage or something, and he was drinking it.

When Colbert made his characteristic sarcastic remarks about not being able to see the point, Kamen responded that 50% of the deaths in the third world could be traced back to water-borne diseases. With this machine, he said, we could save the lives of millions of people per day.

Until that moment, I had thought that he was the self-promoter-yadda-yadda of the GP poster, but his concern and contemplation of the possibilities seemed genuine and sincere. I'm not going to buy a Segway any time soon, but man, but hats off to him if his inventions really do save lives.

FWIW, Colbert had a sip, too.

Re:The Uri Geller of industry

[Lord Ender]

What's wrong with being a free-thinking, self-promoting genius inventor? He's not running for Pope, he invents products.

Re:The Uri Geller of industry

[Anonymous Coward]

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

The very fact you are reading and commenting on Slashdot - from a fairly low UID no less - means you are almost certainly one of those rich people you so disdain. Using a lot of expensive stuff like your computer and internet access which most people on the planet could not hope to afford.

Which makes you a hypocrite as well as an idiot, I guess.

Re:The Uri Geller of industry

[Thng]

I happened to be in Atlanta, GA during the world(?) competition in 06. Quite impressive. I later learned the teams purchased control systems and some other standard equipment from FIRST, but it's all in how they put that together and program the equipment. FWIW, there are divisions from elementary school to college.

Re:The Uri Geller of industry

[Anonymous Coward]

Artery stent, too.

Re:The Uri Geller of industry

[Anonymous Coward]

His water purifier isn't as impressive as think.

His point was not to make something amazing that can turn raw sewage into crystal clear water. It was to make a cheap, easy to power device, that would raise the water quality of as many people as possible.

Take a look at the patent: http://www.google.com/patents?id=GDWqAAAAEBAJ
In it, he gives vapor compression distillation as an example of a purifying method: http://www.aquatechnology.net/vaporcompressiondistillers.html

Re:The Uri Geller of industry

[gilgongo]

The very fact you are reading and commenting on Slashdot - from a fairly low UID no less - means you are almost certainly one of those rich people you so disdain.

Did I say I disdained them? And in any case what has that to do with my UID? I am simply voicing my opinion, which turns out to be ill-informed.

Which makes you a hypocrite as well as an idiot, I guess.

If you say so. Still, I'd rather be that than attack people anonymously.

Air Submarines And The Hunky Men Who Love Them

[negRo_slim]

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.

Re:Air Submarines And The Hunky Men Who Love Them

[JoeMerchant]

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:Air Submarines And The Hunky Men Who Love Them

[a11]

space has a cold side? what would that be - the vacuum? like what you have for a fucking brain?

Re:Air Submarines And The Hunky Men Who Love Them

[Nefarious Wheel]

space has a cold side? what would that be - the vacuum? like what you have for a fucking brain?

Ignoring your manners for a moment, yes it can be said that space has a cold side. If you have an object facing a source of heat (the Sun, for example) then you will have roughly half the object in shadow. The shadow-side surface will be receiving no incident heat from radiation, yet will be able to exhibit cooling by thermal radiation. Thus, a "cold side".

Now, go back to your day job, which no doubt involves waiting under a bridge and shaking down travellers for coins.

Re:Air Submarines And The Hunky Men Who Love Them

[atraintocry]

Whoever modded this informative either doesn't know the difference between matter and energy (like the poster), or is screwing around.

The only real reason that I'm posting this is so that if in a thousand years this page is still in a cache somewhere, and someone sees that mod, I can rest knowing that they won't assume I had anything to do with it. I was not willing to take the fucking chance.

Matter.

Energy.

Get off the internet, go to school.

Re:Air Submarines And The Hunky Men Who Love Them

[Ancient_Hacker]

Okay, think. It's been around for 160 years and you can only point to examples in cost-is-no-object applications. Does that tell you something?

Re:Air Submarines And The Hunky Men Who Love Them

[Ancient_Hacker]

Please show me a single verifiable efficiency number for a closed loop Stirling engine in use for more than 6 months in the real world. I have not been able to find one. That may be a clue.

Re:Air Submarines And The Hunky Men Who Love Them

[JoeMerchant]

Don't know how you would go about verifying these claims, but, these guys claim 800 Watts out at 1/5 gallon of gasoline per hour. If you trust the last link there, a gallon of gasoline contains 36KWh of energy, 1/5 of that is 7.2KWh, giving 11% efficiency if you're getting 800Wh of electricity out while burning 1/5 of a gallon of gas.

Kamen has a pile of Sterling related patents, many centered around more efficient conversion of fuel to mechanical output from the engine. In the past, he has been very cloak and dagger regarding his engine progress (or, at least when I visited DEKA shortly pre-Ginger release, he was). Maybe if you really care, you could approach him and see if he has working models that exceed 11% efficiency.

Re:Air Submarines And The Hunky Men Who Love Them

[Ancient_Hacker]

11% is mighty good for a Stirling.

But lamentable as a diesel generator can do 33% and for 1/5 the initial cost.

Not many folks are going to spend five times as much for the privilege of burning three times as much fuel.

And the diesel has proven reliability and can be fixed most anywhere. While the Stirling has to be shipped to New Zealand if it goes awry.

Re:Air Submarines And The Hunky Men Who Love Them

[JoeMerchant]

Would be a tough call for me, if I were living on a 50' boat with the thing. I'd rather sit on diesel tanks than gasoline, but I'd also rather not listen to a diesel run, kinda defeats the point of getting out with nature.

And, can a diesel really generate 2400W on 1/5 gallon per hour? My (admittedly, portable gasoline) Honda generator will suck down roughly 1/2 gallon in about 3 hours if its loaded up to a continuous 800W. That 11% figure also includes generator efficiency, or lack thereof.

As for sending it off to NZ for servicing, that's not a design fault, just the present reality of what's popular in the market. Will Sterlings gain popularity? Probably not, but that doesn't mean they are a flawed concept, or impossible to execute. Rotary (Wankel) engines are superior to piston in power to weight ratio and packaging size, but they never took off, except in certain segments of the light aircraft market. Wankel is hardly a flawed design, and if it were developed to the extent that the piston engine has been, it could make strides in efficiency and its other shortcomings, but it has been mostly forgotten and lags in development roughly back where the piston engine was during WW II, it has seen some basic refinements, but nothing like the billions of hours spent tweaking pistons & valves.

Stirling not connected, not enough to power car.

[guidryp]

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

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.

Just please tell me...

[Anonymous Coward]

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...

[iminplaya]

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

Too Slow

[caller9]

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

[Miseph]

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.

Re:Too Slow

[willworkforbeer]

I would hear more of these "boobs" and "shaved armpits" of which you speak. Photos, or they never happened.

Re:Too Slow

[Anonymous Coward]

You do know that women (especially younger ones) really like cute small cars, right? Sports cars are toys for boys that never grew up, big sedans and SUVs are for fat middle-aged people.

OK, so I drive a Yaris and my fiancee is hot. 3

Re:Too Slow

[Nefarious Wheel]

You do know that women (especially younger ones) really like cute small cars, right? Sports cars are toys for boys that never grew up, big sedans and SUVs are for fat middle-aged people.

I drive a Nissan Patrol, you insensitive clod!

Oh, wait...

Wood burning car?

[kramer]

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?

[JoeMerchant]

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

Re:Wood burning car?

[Anonymous Coward]

Why not put the Stirling (driving a generator) in the basement ... run waste heat thru it ... wood stove (any other cheap non-polluting fuel) and drive a plug-in hybrid?

This is not a Ford

[howcome]

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

why use the stirling when there is solid state

[Anonymous Coward]

Does anyone remember this solid state engine 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.

Re:Gas Turbine?

[iminplaya]

Where have you been?

Stirling sinks, give me these three instead:

[sjs132]

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:

[JoeMerchant]

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.

Re:Stirling sinks, give me these three instead:

[Anonymous Coward]

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...

Something like a Mr. Fusion would be a plus, but "Big Oil" has been supressing that Tech since 1984.

Sjs132 is DEAD. Hasbin for 100+ years. Yup, he's a zombie, bu has about all. Get over i... Insead I'd like to read somehing from CowboyNeal or wier.

Somehing like a Mr. Oxymoron would be a plus, bu "Big Al" has been supressing ha ech since now hen. Oh very funny Big Al, sop messing wih my keyboard! You can' silence me!

Re:Stirling sinks, give me these three instead:

[sjs132]

Bummer, I'm dead... Now what?

Re:Stirling sinks, give me these three instead:

[Nefarious Wheel]

The stirling is DEAD. Has been for 100+ years.

P|-|33R teh Undead Stirling! RAWR!

He just likes building neat stuff

[zogger]

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

[JoeMerchant]

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.

Re:He just likes building neat stuff

[zogger]

A long time ago before he hit it big obviously. When I said a ten foot backwall booth, that is the cheapest you can rent on a show. I worked tradeshows for 15 years, thousands of shows, so I don't recall the exact show now, sorry. I just remember that chair thing (must have been a prototype because this was some years ago), and another invention at the show, a hovercraft-like people mover to move patients from beds to gurneys, that was cool too. Pretty slick, real thin, just slipped under the patient, turn on a small air pump, they get picked up just a fraction of an inch making it easy to slide them on and off to another surface. Stuff like that I remember from most shows, because I always liked cool inventions, the rest is a big blur of wingnuts and rotating logo signs, sales weasels and booth babes...heh.

    I guess he has enough loot now, but the rest of my points stand I think, he's just a way smart guy who can pull it-whatever wild "it" thing he thinks up- off to completion. And his ideas go to benefit people in general, help the sick and ill, as another pointed out, help the poor get clean water, etc. His segway idea was at least an attempt at something completely alternative to either big cars or mass transit, sort of give the benefits of both. Unfortunately, it really would take cities being designed around them for them to work as he intended.

Re:He just likes building neat stuff

[Anonymous Coward]

His /. ID is lower than yours, so... Wait, it doesn't work here.

Re:Gas Turbine?

[gyrogeerloose]

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.

Stirling Engine

[cwsulliv]

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.

Re:Gas Turbine?

[superdave80]

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?

[gyrogeerloose]

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.

Would be better with a Carnot Engine

[n2rjt]

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.

Re:Gas Turbine?

[superdave80]

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:Stirling not connected, not enough to power car

[JoeMerchant]

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.

Re:Gas Turbine?

[gyrogeerloose]

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.

Re:Gas Turbine?

[Anonymous Coward]

Good thinking but it turns out turbines are not very efficient at peak efficiency either.

Certainly all combustion engines are 0% efficient at idle, but turbines are below Stirlings and even gas engines for running efficiency.

They're well-suited to the military, however, where the noise, low efficiency, and compact size yet massive output power make them ideal for aircraft and tanks.

Re:Gas Turbine?

[Rei]

It's not. "Minutes" isn't a problem at all for ER-EVs. Gas turbines integrate quite nicely. They take the time that they need to to start up and can run for a dozen minutes or two, then they shut off. DesignLine busses use Capstone microturbines for this very purpose. The Capstones use an air suspension so that the shaft encounters nearly no friction. As a consequence, they have very long lifespans.

Re:Gas Turbine?

[Anonymous Coward]

They also take a large amount of fuel to start up compared with conventional piston engines. For example, the turbine in an M1 Abrams tank takes about 10 gallons to start up, and burns about 12 an hour at idle. Granted, that 1500HP turbine's 20 times bigger than anything you'd see in a hybrid passenger car, but the same principles still apply for smaller engines. For a hybrid that frequently turns the engine off and on (like a Prius does), that'll add up fast. And if you leave it on all the time, you run into the idle fuel burn issue.

Why not reuse some existing ideas

[tautog]

The strength in Stirling's design is that it's effective at scavenging heat energy. So rather than powering it directly, why not use a traditional ICE or turbine for charging the batteries and then use the Stirling to scavenge energy like subject of this /. article:

http://science.slashdot.org/article.pl?sid=05/12/15/0037238

Maybe even take it step further and put the Stirling downstream of the steam engine?? With modern alloys and using freon or gaseous ammonia instead of water, you can greatly improve your efficiency.

Any relation to... ?

[Whiteox]

"Dean Kamen, (inventor of the Segway

??? Is he related to Kamen Electra ???

Use metric.

[Anonymous Coward]

Why the fuck is a high technology site like Slashdot still using Imperial?

I mean come on, you're nerds, people. Move to SI.

Re:Use metric.

[Anonymous Coward]

You must be new here.

Actually, deducing from what you wrote, you ARE new here.

Re:Use metric.

[otis wildflower]

Because Metric is French.

Freedom fries.
Freedom toast.
Freedom dressing.
Freedom tickler.
Freedom three-way.

Re:Use metric.

[Russ Nelson]

"Shut up, eight-millimeter-dick."

It just doesn't have the same ring as "pencil dick", sorry.

A few questions: Stirling engine thermodynamics

[Smoke2Joints]

While this story is up, Id like to get some questions answered. Im trying to design and build a beta-type stirling engine to be hooked up to a solar collector dish of diameter 1.8m, and would love some input.

Does anyone know the ideal dimension ratios of the displacer and power pistons, and the piston strokes? Or are there no real rules at all?

Re:A few questions: Stirling engine thermodynamics

[Whiteox]

33cc is optimal for the piston size/stroke which can be oversquare (stoke is longer than piston diameter). or undersquare (stroke is shorter than piston diameter).
Longstroke = more torque, short stroke = more power at high rmp. - Just scale it up if you need bigger.
Your problems will be the heat exchangers - very efficient at heating water btw.
Wiki has a good description and will give you a few types to consider.
There's what you want already built in Spain: Point focus parabolic dish with Stirling engine and its solar tracker at Plataforma Solar de AlmerÃa (PSA) in Spain.
http://en.wikipedia.org/wiki/Sterling_engines
There are also other 'solid state' alternatives too.
Just google it to find a pile of hobby sterling engine sites.
There are also commercial sterling fridges, water-heaters and power generators ready to go.

Re:A few questions: Stirling engine thermodynamics

[Smoke2Joints]

Thanks, Ive done a ton of research, but found nothing really dealing with the characteristics of the pistons themselves, and how this determines power output - and crank diameter.

Curious, why 33cc in particular?

My design will be a rhombic drive beta btw.

Re:A few questions: Stirling engine thermodynamics

[Whiteox]

I read about it (33cc) in a local library before the internet. It turned out to be ideal size/weight/power ratio for small single cylinder motors. Don't ask me the source.
There must be more modern studies that I'm not aware of.

I don't think the rhombic drive would be suitable.
However if you mount it through the centre of the dish, the heat collector would need to be extended to the focal point of the dish and the cooling radiator would need to be behind the dish. That would give enough temp. difference for it to work really well.

I've tried to design one on the same principles but using diaphrams instead of pistons. Still working on it.

Re:Gas Turbine?

[WalksOnDirt]

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

As your link states, they are too expensive.

Re:Wow. More of the same.

[cgenman]

Note the 60 mile operation is for pure battery, not hybrid Stirling operation.

A better article is here.

This isn't going to last

[PPH]

can run on any fuel

Not only will this upset Big Oil, it will attract the wrath of the taxing authorities.

Re:This isn't going to last

[Anonymous Coward]

Not only will this upset Big Oil, it will attract the wrath of the taxing authorities.

Are you sure about that? Up until last week the taxing authorities and "Big Oil" were the same thing, are they still?

Re:This isn't going to last

[NoisySplatter]

I wish I had some "trollishly insightful" mod points to hand out.

Since a lot of our road funds come from the sale of gasoline I wonder how that will affect vehicles capable of running on alternate fuels. As it is right now people with higher efficiency and alternate fuel vehicles are pretty much dodging their share of the "road maintenance" gas taxes.

Re:This isn't going to last

[PPH]

Here are a few of my observations on alternative fuels and taxes:

1) Back in the dark ages of the first Arab oil embargo, I converted my pickup truck to propane. At that time (I haven't checked for years) propane filling stations did not collect road tax. The state created a special arrangement wherein I purchased an annual sticker authorizing me to utilize untaxed fuel. Since I filled my pickup truck at a self serve station, I could have easily skipped the permit, as no one was present to check. But the permit was cheap, about $50/year, which I figured broke even based on average personal use and equivalent gasoline consumption. High mileage or consumption fleet vehicles were getting a great deal at this price.

2) Remember the EV 1? Plug it in to a special charging station in your garage overnight to charge. Remember that 'cool' inductive coupled 'plug' they used to charge it? I always wondered, "Why not a standard 3 prong plug, so when you stop elsewhere overnight, you can just find a convenient outlet?" I'm guessing that, although not stated explicitly, this design forced users to plug into a dedicated charging unit. Which can be metered by the taxing authorities.

3) Bio-diesel: All those early adopters actually went public, telling people how they were collecting used cooking oil to run in their cars. Although there was no outcry over the tax issue, restaurants and other oil sources were quickly contacted by commercial reprocessors, who have effectively cornered the market on many oil sources. Now, you can buy thir product at a pump. Fully taxed, of course. And often sold through standard motor vehicle fuel marketing channels, so as not to cut big oil out of the picture either. The early adopters should have kept their mouths shut.

4) Plug-in hybrids. Where are they? Its dead simple technology, as many hybrid hackers have demonstrated. But the auto manufacturers drug their heels. Meanwhile, the tax people have been trying to figure out how to collect from these things. Once they come up with a plan, I'm sure the manufacturers' 'technical' issues will be magically resolved.

This last point illustrates the evil of the tax system. Once the government gets their fingers into the pie, they throw roadblocks in front of new technology if there's a chance that it might divert their revenue stream. Pretty soon, we end up with a socialist 'permittive' regulatory system. One where you need to seek government review and approval to do anything new instead of today's system where, within existing rules, you do what you want until the gov't steps up with a valid reason to regulate it.

But

[TheLink]

"It's damn too easy to get yourself into a road accident"

Actually that's where the real savings to the environment are. The "green" proponents don't usually mention it, since it kind of ruins their cunning plan ;).

The obvious reason this car wins:

[sam_vilain]

Fuel: anything liquid and combustible (Th!nk City); anything liquid, combustible, with a flash point equal to or greater than the equivalent of a mix of 89% octane (Aptera)

Stirling engine to power the HEATER?

[Animats]

He's using a Stirling engine to power the heater? Fuel to heat to air expansion to electricity to heat? That's a bit much. Just use a fuel-powered heater.

A quiet little 1KW Stirling engine would be useful to have around for backup power. One of those to power your furnace blowers, provide emergency lighting, and keep the UPS alive would be useful as a home accessory.

Useless Specs

[omb]

OK, the queue of US carmakers outside the Congress grows again, and these idiots continue to advance a car with specs that no-one except a green millionaire would want to buy (because it is his 5th car).

To be useful you need 140 KPH, 500K range, 1 hour service time. If they cant produce that (a) dont give them any money, it will be back to 7l Surburbans in 6 months (b) fire the CEO; otherwise the far-east will eat your lunch in the up-turn.

What, no Kamen Rider jokes?

[Bossk-Office]

What, no Kamen Rider jokes?!

smaller size efficiency?

[emj]

What exactly is it that makes them worse at small sizes, and what is small sizes? (Great article by the way)

So are small Diesels

[Kupfernigk]

The catch with the Stirling is that it is always playing catch up to small Diesels. All over the world, small generators are powered by Diesel engines of one or two cylinders which can be very thermally efficient (35-45% is readily achievable at constant speed), and the sheer production volume and cumulative R&D makes them very cheap and reliable. The problem is in the US, where the environmental regulations favour gasoline over Diesel and claims of deaths from Diesel particulates are regularly used to maintain the status quo. That these claims are unproven (and difficult to separate out from the vast number of annual deaths due to smoking) doesn't matter.

Stirling engines used in military system have the advantage that cost is almost irrelevant, but Stirling for road vehicles has the chicken and egg problem - to prove the viability of the concept, you need to get up to big manufacturing volumes to get the reliability data and drive costs down. The takeover by Diesels for cars in Europe was made possible because the technologies for advanced Diesels were already in wide use in marine engnies and just had to be engineered down the size scale. This situation does not exist for Stirlings.

On the pollution front, it is true that Stirling engines will burn most fuels, but the downside is that it is very hard to produce a multi-fuel engine that does not produce a lot of soot from some of those fuels. You can drive a small Sitrling by burning wood - if you don't mind dismantling the heat exchanger periodically to get the gunk out.

Kamen's idea is, I feel, less about viable technology than pressing buttons with the US Government's priorities. It would be more economical, and more reliable, to fit a small off the shelf packaged generator of the sort that is already available to fit into boat lockers. Compare the price of one of these with a Whispergen and you will see the point very quickly.

Yahbut...

[Anonymous Coward]

...the average driver here in Brisbane, Queensland, probably drives 3-5km/hr over the limit where they think there might be a speed trap, and 10-15km/hr over where they don't.

The non-average ones do 90 in a 40 zone and abuse you for only doing 50.

I used to think Brisbane drivers were fairly good. Then I lived in Detroit for a year, where I witnessed some truly appalling driving, that was very nearly matched by what I saw when I got back to Brisbane.

Still, they're much worse down on the Gold Coast...

Well.. TH!NK have actually produced vehicles

[Colin Smith]

They have a factory actually producing vehicles and are planning to make profits... Aptera have a proof of concept car. I suspect their numbers are based somewhat on imagination.

 

Re:Well.. TH!NK have actually produced vehicles

[Rei]

Th!nk is only about six months ahead of Aptera, production-schedule-wise. And it's complete nonsense to claim that Aptera only has "a proof of concept car", as any cursory reading of the information collected over on the Aptera Forum will convey.

Computer Analogy

[cyclomedia]

You are correct about all-electic-vehicles vs energy density, but the intermediate step we are moving to can tide us over the next few decades until we reach that goal/run out of oil.

To explain why I will use a reverse computer analogy.

Your DVD/CDR in the burner is the constant-speed (IC/stirling) engine
The RAM buffer is the battery/ies
The Hard drive/network share is the variable/unpredictable road conditions.

In the type of hybrid vehicle we're moving towards the battery doesnt need to store ALL the energy required to drive around, the energy is still stored in the liquid fuel. the engine+battery array convert and feed the energy to the non-transmission (As described in earlier posts) and in the process greatly improve the overall efficiency, conversion losses included.

Heat storage?

[Lazy Jones]

I have no idea how "real" this is, but bsrsolar.com claims to have heat storage technology with density 0.8KWh/Kg (= 2.88 MJ/Kg), which is better than even nanowire LiIon batteries (see wikipedia).

So basically you could build a car with only a small (expensive) "buffer" LiIon battery and cheaper/lighter heat storage with Stirling engine as the main source of power.

I would sure love to have a huge solar dish on top of my car, it would look so 1930's sci-fi-ish...

Waste heat

[BiggerIsBetter]

You could set up a Stirling engine to run on the waste heat from other processes.

So given that, could you use the waste heat of a turbo-diesel / petrol engine (stored in the coolant) to increase the overall efficiency? Eg, IC gets 35%, and the Stirling reclaims 45% of the left over 65%? The Stirling engine would presumably run a generator to charge & drive the electric component of a hybrid drivetrain. You get the best of all worlds, with the overhead of additional complexity - which Toyota (among others) has shown we can deal with if we want to.

Re:Waste heat

[TigerNut]

The issue with that, is that the Stirling engine's efficiency is limited by the absolute temperature differential between the hot and cold side. So a perfect Stirling engine using waste heat from the engine's coolant (assuming for a moment it is maintained at 97 degrees C by a thermostat, and the ambient temperature wherever the engine is dumping its heat is 27 degrees C), will have a best case efficiency of 70/370 = 23% (of the approximately 30% of the heat wasted by the IC engine that is available in the coolant - the remainder goes out the exhaust) .
Then you have to convert that 23% into a useful form of work (let's say electrical energy) which incurs additional efficiency loss.

Not that there's anything wrong with that... using an extra 5 or 6 percent of the chemical energy in the fuel for useful output still counts, but there is a pretty high cost in money and weight associated with getting that extra energy out. If it's done in a vehicle you have to account for the decrease in acceleration efficiency due to the extra mass...

Re:Waste heat

[StalinsNotDead]

limited by the absolute temperature differential between the hot and cold side.

You're right! Bring back the McDLT!

It keeps the hot side hot AND the cold side cold.

Re:Waste heat

[BiggerIsBetter]

Good post. This 6-stroke engine (petrol + steam) might be more interesting then...

http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060227/FREE/302270007/1023/THISWEEKSISSUE

Not b3ta.

[Anonymous Coward]

I did a double-take at the diagram on that wiki page. Had to make sure I'm not browsing b3ta.com here...

One more Stirling engine that makes a difference

[pritchet1]

Infinia Corp should be going commercial with their Solar Stirling Engine soon - http://peswiki.com/index.php/Directory:InfiniaCorp They started 20+ years ago working on vehicles and migrated to putting power generating systems on Mars. The early versions are still running without maintenance after 17 years in service. They already license the technology to a few combined heat and power outfits in Europe and Japan. They expressed no current interest in trying to replace the Internal Combustion Engine with the Stirling Engine in vehicles.

Re:Wow. More of the same.

[illumin8]

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.

You might not care, but the 20 other drivers stuck behind you on the freeway on-ramp that have to merge into traffic going 70 mph at a speed of 30 mph care a great deal. Have you even thought about the traffic accidents you might cause trying to drive a vehicle like that in normal freeway traffic? 12 seconds is barely acceptable, but 20 seconds is an accident waiting to happen.

Like I just did yesterday.

What vehicle are you driving that allows you to go 300 miles on a charge? I'm curious to know.

Re:Wow. More of the same.

[Anonymous Coward]

I don't care if it takes me 12 or 20 seconds to reach 60mph

You would if you were driving in an urban environment, with normally timed traffic lights. Drive 1 mile, wait 3 minutes, drive another mile, wait another 3 minutes. Where's your efficiency now?

Try it in traffic... just think about the miles-long traffic jam building up behind you... (not to mention the guy tail-gating you, in the SUV, who's running late for a meeting).

Serial hybrid, not parallel

[Russ Nelson]

Some yard engines are now built as modular hybrids, with three engine bays. One of the engines can be replaced by a bank of batteries, so you don't need to run the engines for short pulls or shoves. The engines are standard (large) Cummings diesels, mounted on pallets. So at least in theory it would be straightforward to replace them with gas turbines that only run when needed to charge the battery.

wtf?

[Markimedes]

"The Stirling cycle is notable for its perfect theoretical efficiency; however this as yet unrealized ideal remains an immense engineering challenge. Nevertheless, current designs are useful and versatile."

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

Stargate Tech to the rescue.

[jameskojiro]

When they had to power the X-303 with a Naquadria reactor they had to dump some of the excess energy into a "buffer" of sorts to prevent the ship from blowing up. Why not make a "buffer" for the car that can provide the needed acceleration and can be re-charged by either the battery pack or the Stirling engine.

Well that is until we can power cars with teeny tiney ZPM modules.

Why not thermoelectric modules?

[Anonymous Coward]

Why bother with a sterling engine when there are solid state devices that do the same thing?

Re:Stirling not connected, not enough to power car

[knails]

No, the stirling engine doesn't drive the car, it recharges the battery when the battery is run down. The battery drives the car, and the stirling engine can run additional features and then make sure you don't run out of battery in the middle of nowhere.

Re:Wow. More of the same.

[torkus]

Actually in a full electric car the heat would be more costly in terms of power.

In an I.C.E. there's *plenty* of waste heat, a small portion of which is used to heat the car. In a EV there is some waste heat but it's much less constant and lower temp (i assume LiION cells would *not* be happy at 100c). You're stuck with resistive heating which is essentially 100% efficient.

OTOH, Modern air conditioners are more than 100% efficient. Check wiki or anywhere for details on EER. Essentially an AC with an EER of 12 will provide 12000 BTU (or approx 3.5KW) of cooling at a cost of 1KW of energy(EER = btu/power. 3.5 / 1 * 100 = 350% efficient.

Hency why people can afford to cool a house with AC but still turn to oil/gas for heating (in most cases)

What would be the most taxing test is your front defroster. AC to dry the air, then heat to warm it up.

Re:Wow. More of the same.

[Hucko]

Yknow, I have been getting better efficiency around town than I do on the highway. Yep Dead Set True. I get 8.06l/100km around town and 9.6l/100km on the highway.

Why?

1. I only use enough energy to get me to the next point of change.
2. I turn off the car as it rolls up to the lights and wait till the perpendicular lights turn red before starting.
3. I let hills maintain my speed and dont try prove Im the fastest driver around. As much as is possible without altering the common driving practices I let other drivers take precedence. I get out the way of those behind me.

I have not lost any perceivable time getting from A to B. I drive a Holden Rodeo diesel ute* that until my wife and I worked out how we might be more efficient drivers was getting 10~11l/100km.

1. was the biggest fuel saving; 2 and 3 have proven to be only just registrable. If they/I worked better, Id be well into the 7l/100km.

* Ute is an Australian Slang for Utility. I didnt know this until an American expressed confusion at the word. (Hey, I was young at the time.)

I thought this was old news...

[Redbluefire]

Dean Kamen has been presenting this thing for months now... I even got to sit in it at the FIRST Championship earlier this year. More. photos. here.
Aaaand obligatory photo of this poster driving it.