Electric cars are a pipe dream

[Trippy]

Actually that's peak power which you can only get with a significant load. If you apply that much power to a motor without a load it will very quickly overspeed and self destruct.



I think you meant "increases." Without any phase advance a synchronous motor takes almost zero current at its synchronous speed when there's no load on it. (And DC motors take almost zero current at their base speed when there's no load on them.)

Vacuum cleaner motors often speed up with their intakes blocked because their fans stall when there's no air. This decreases the torque on the motor. Their speed increases to compensate and they have troubles. (They tend to have cheap series wound universal motors, which do not handle overspeed well.)

You seem to be correcting me by posting stuff that is more or less what I said?

 

[Trippy]

Actually that's peak power which you can only get with a significant load.

No, it is what I said it is.

It is the RMS current drawn by the motor when it is operating at peak power (with peak current derived from the RMS value).

 

[adoucette]

True - but if he had bought a Nissan Versa he would have come out way, way ahead of both of those people (if money is your only criteria.)

Doesn't look like it.
The car isn't much cheaper then the Camry (18,000 for SL model), it's smaller, yet gets worse gas mileage than the Camry, and has less of a trade in value.

Seems you would end up about the same after 150,000 miles, but you would be driving a less comfortable car the whole time.

http://www.fuelly.com/car/nissan/versa
http://www.kbb.com/nissan/versa/200...icetype=trade-in&isnotabs=true&creativeid=443
http://www.nissanusa.com/versa-hatc...y.Versa_Hatchback.Versa_Hatchback.vlp.button1

 

[Billy T]

Dreamt up by Boston's MIT-Media lab, the concept was developed by a consortium of seven small Basque firms under the name Hiriko Driving Mobility, with a prototype unveiled by European Commission president Jose Manuel Barroso.

Is an electric two-seater with no doors* whose motor is located in the wheels and which folds up …The vehicle's four wheels turn at right angles to facilitate sideways parking in tight spaces. Its makers are in talks with a number of European cities to assemble the tiny cars that can run 120 kilometers (75 miles) without a recharge and whose speed is electronically set to respect city limits.**

They envision it as a city-owned vehicle, up for hire like the fleets of bicycles available in many European cities, or put up for sale privately at around 12,500 euros. Several cities have shows interest, including Berlin, Barcelona, San Francisco and Hong Kong. Talks are under way with Paris, London, Boston, Dubai and Brussels.

* You get in with top folded up but the wheel base fully expanded. Perhaps then only the front window section is folded up to enter. (less weight for frail person)

** IMHO, that may be a good idea for all new cars. Would stop the crazy drivers on hiways from weaving in and out of lanes at 30 or more mph above the speed limit. I don´t care if they kill them selves by running into a post etc. but usually they kill others too. With modern electronics and RF (sort of like the no stop drive thru toll gates) periodically placed in hiways when speed limit changes, doing this should have little cost (negative net cost when the bigger picture of hosiptal expenses, etc., are considered.) Modern cars already have the computation power and simple RF reciever giving it data is very low cost. Much less than seat belts, which are made mandator with much less justification than automatic enforcement of speed limits.

 

[elte]

I would like to have a tiny car to supplement my bicycle, however, it wouldn't have to fold up. We could use lower pricing, as well. The future is generally going to be much poorer, and it will go more easily if we begin to account for that right now, especially since the average real income of Westerners continues to decline.

 

[Billy T]

Please see second (**) footnote recently added to post 2486 about desirability of automatic speed control in ALL cars.

I would like to have a tiny car to supplement my bicycle, however, it wouldn't have to fold up. We could use lower pricing, as well. The future is generally going to be much poorer, and it will go more easily if we begin to account for that right now, especially since the average real income of Westerners continues to decline.

If "folding up" car causes little trouble why not have it so two or three can park in space a big US car needs? The rotate wheels and drive straigt to the curb is attractive to many who want easy parking in very tiny space.

They will be exporting from Spain to World, but I doubt that will be in volume enough to save Spain from economic problems with its debt. China has world´s worst trafic jams and parking space problems AND the money to buy all they can produce - at least until their new, much larger capacity, factory is in China. Just what US needs : Advanced MIT technology being made in China for US & world markets.

BTW, yesterday I saw two new Chery cars on the hiway. We passed one and another passed us - 2nd was not the same as the first seen again as it had spare mounted on the rear door.

 

[Grumpy]

Trippy

But that's peak current with absolutely no loading on the motor

Peak current occurs under FULL LOAD, not no load. Here are the spec for a model aircraft brushless motor(functionally equivalent to an AC motor)

SPECS:


Voltage: 7.4-11.1V

RPM/V (Kv): 950

Current: 13-18A
No Load Current: .6A

Power: 145W

Shaft Diameter: 3mm hardened steel

Recommended Props: 8x6 to 11x7 Slow Flyer (dependent on voltage)

Weight: 1.8 oz. (50 grams)

Notice the difference between no-load current and rated current(the first number is continuous the second is peak). No load current represents the loses(bearing drag, wire resistance , and copper and iron loses).

By the way, there is no possibility of overspeed in this type of motor as the speed is directly controlled by the frequency of the electronic commutation regardless of load. The same is true for the AC motors used in EVs. Even vacuum cleaner motors are limited in overspeed by the frequency, when running at high load(IE hose not blocked)they turn slower due to slip, slip is dependent on load, when running at low or no load(when hose is blocked)they run at or near syncronously to the frequency(which they are designed to survive). It is in DC motors with mechanical commutation where there is danger of ovespeed.

Grumpy

 

[billvon]

Peak current occurs under FULL LOAD, not no load. Here are the spec for a model aircraft brushless motor(functionally equivalent to an AC motor)

Keep in mind that different motors have different load curves. Series wound universal motors (often used for very cheap appliances) can see an increased current at reduced load. Specifically they increase speed as load drops off, which on a series wound motor decreases back-EMF and thus increases speed further. Thus they can "run away" and destroy themselves if they are suddenly unloaded.

By the way, there is no possibility of overspeed in this type of motor as the speed is directly controlled by the frequency of the electronic commutation regardless of load.

Overspeed can happen in both conventionally commutated and electronically commutated DC motors, but is rare because such a motor will never run past it's "base speed" set by the DC voltage available. Thus a motor rated for 2000 RPM at 12 volts will not exceed that speed at that voltage without more exotic drive strategies like phase advance.

Even vacuum cleaner motors are limited in overspeed by the frequency, when running at high load(IE hose not blocked)they turn slower due to slip, slip is dependent on load, when running at low or no load(when hose is blocked)they run at or near syncronously to the frequency(which they are designed to survive). It is in DC motors with mechanical commutation where there is danger of ovespeed.

Universal series wound motors, often used in appliances, run on AC but are functionally equivalent to series DC motors - and thus can run away.

 

[Billy T]

To hell with batteries - use zebras:

“a special bacterium, named TU-103, in zebra dung that is capable of breaking down the plant material, cellulose … TU-103 is a triumph on several levels.
First, it has eliminated the two-step process of breaking down the cellulose to sugar and then fermenting it to create ethanol. TU-103 does the process in one step. Not only that, the end result is not ethanol, but butanol, which packs more energy and can be used to run vehicles directly without modifications. …”
From: http://www.horsetalk.co.nz/news/2012/01/211.shtml

I read this and may have already posted a month or so ago but if so, it was direct from the NZ group or newspaper.

 

[Billy T]

If you don´t want butanol (see my last post) use natural gas, growing cheaper every month with global growth for mobile fuel exponentially increasing:

Note fracking for NG may pollute ground water and is not renewable as is easy to store butanol (or sugar cane alcohol) made from grass, etc. (Sugar cane is a "grass" but probably any cellulose will do soon for making either butanol or ETOH.)

 

[adoucette]

That would be impressive if it weren't for the fact that there are roughly 800 million motor vehicles on the road, leaving NG at a pitiful 1.5% of the total, and total annual motor vehicle production is in the range of 80 million units, which means the annual production of NG remains about 1.5% of the annual total as well.

 

[Billy T]

That would be impressive if it weren't for the fact that there are roughly 800 million motor vehicles on the road, leaving NG at a pitiful 1.5% of the total, and total annual motor vehicle production is in the range of 80 million units, which means the annual production of NG remains about 1.5% of the annual total as well.

All true, I assume, but exponential growth wins in the end, no mater how far behind at the start. Part of the reason it is now exponential, I think, is as more switch to NG, more filling stations provide NG so more switch. That is the basic mechanism of exponential growth - get more as you have more.

Thus last part of you post, idea that NG will stay at 1.5% probably is not true.

 

[river]

worlds fastess electric car , for fun

http://www.terradaily.com/news/car-tech-05u.html

 

[adoucette]

All true, I assume, but exponential growth wins in the end, no mater how far behind at the start.

But it's not exponential.

Indeed the percent rate of growth for the last two years is quite a bit below the average since 2001.

~16% in 2009
~14% in 2010

Part of the reason it is now exponential, I think, is as more switch to NG, more filling stations provide NG so more switch. That is the basic mechanism of exponential growth - get more as you have more.

Except it is not exponential.

Thus last part of you post, idea that NG will stay at 1.5% probably is not true.

We'll see

 

[Billy T]

But it's not exponential. ...

The black curve of graph has equation y= 352677 exp(0.2142x) and fits remarkable well over two decades.

Of course there are very slight difference from the exponential growth curve in one year to the next, just as exponential growth of algae in a pond has minor variation from perfect exponential growth. (Wind & amount of sunlight variations being the main causes for variation for exponential growth of algae, I think.)

I don´t think you can find any actual growth data that is exactly an exponential; probably none that fits so well thru 20 annual data points that it needs five significant figures to fit the actual data as this exponential fit does.

 

[adoucette]

You can fit a curve to it over this short period but that doesn't mean that the rate of growth isn't slowing down.

It is.

If you fit the curve to the last four years you will see this deceleration in growth.

So if it continues to slow down, it will soon peak.

 

[Billy T]

You can fit a curve to it over this short period but that doesn't mean that the rate of growth isn't slowing down.

20 years & and 20 annual data points is not a "short period" when speaking of exponential growth. This exponential fits 20 points very well - average error a few percent.

All exponential describing all real events do saturate - for example when algae covers half the pond it must stop doubling, but this exponentail is far from saturation still as now only 1.5 % penetration ("of the pond").

 

[adoucette]

Well the December and thus 2011 sales figures are in:

The Volt has shown growth over the past four months of the year:
723 in September
1,108 in October
1,139 in November
1,529 in December (1/3 were fleet sales)

For a year total of 7,671 Volts

The Leaf finally had a positive month after declining sales in October of 849 units and November of just 672 units, they sold 954 units in December.

Which was still far under the Volt.

For a year total of 9,674 Leafs.

Or ~18,000 total EVs for the year (estimated ~600 Tesla sales) and $135 Million in Federal Incentives (~1,500 EV sales per month).

2012 should add the Electric Ford Focus to the mix, but priced at $40,000 and 100 mile range I suspect similar anemic sales volumes to the Volt and Leaf.

Tesla and Toyota are going to release an EV version of the Rav 4. Expect it to be very expensive with a range of 100 miles.

Toyota may be the big winner with the release of the Prius Plug-in for ~$33k with a 15 mile battery range.

Toyota is still in the limited production mode for pure EVs next year (less than 1,000 or so cars world wide)

Honda's EV the Fit, is a subcompact hatchback at $37 k and will initially only be sold in California and Oregon (late spring?). Honda claims 123 miles in city driving, which suggests that the car is underpriced, which may be why Honda only plans on making about 1,100 Fit EV's over the next 3 years.

Mitsubishi sold just 4 of its MI EV in November, I can't find any December sales data. It has a short range of but 62 miles and about $30k.

Former BMW designer Henrik Fisker will try to sell his $102,000 plug-in Karmas with but a 30 mile battery range before going to IC.


http://www.the9billion.com/2011/11/04/ford-taking-orders-for-2012-focus-electric-priced-at-40000/

http://www.torquenews.com/106/chevy-volt-wins-december-sales-battle-nissan-leaf-wins-2011

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

Well January's Sales figures are in and they really SUCK if you were hoping for any growth in the EV sales market.

Nissan sold a pathetic 676 Leafs, down from the 954 last December

Chevrolet sold an even more pathetic 603 Volts, which is less than 40% of it's 1,529 sales in December.

Mitsubishi sold just 36 of its 'i' electric cars (Though sales were only in 2 states, so don't read too much into this very low number)

That gives an electric-car total of ~1,315.

Or quite a bit less than last year's average monthly sales.

That number doesn't include any sales of the Ford Focus, which technically went on sale last December in limited markets, but no sales numbers have yet to be provided for this 100 mile range EV that is selling for $40k. Nor does it include any sales for the Fiskar or Tesla as neither of those companies are releasing any sales figures (but they are small or they would)

 

[Silverranger123]

Quite a pessimistic post !

I wholly dis-agree with you.

My reason is simple, 50 years ago the idea that one day we would have personal devices that allowed us to contact people on the other side of the globe from wherever we are, to watch hi-def movies and listen to crystal clear audio. All of this would of been a dream that most people would say is impossible.

The truth of the matter is that fossil fuels will not last forever, man will have to diversify. Perhaps wide scale affordable electric vehicles will not happen in our lifetimes, but one thing I am sure of is that it will happen. Why, because we have no other choice.

 

[adoucette]

Quite a pessimistic post !

I wholly dis-agree with you.

How can you disagree with the actual number of EV sales?

They are what they are.

My reason is simple, 50 years ago the idea that one day we would have personal devices that allowed us to contact people on the other side of the globe from wherever we are, to watch hi-def movies and listen to crystal clear audio. All of this would of been a dream that most people would say is impossible.

Not at all.

You must never have read Dick Tracy, this was over 60 years ago.

Besides, 50 years ago we were getting ready to launch the first Geo-synchronous Telecommunication satellite, and 48 years ago we used it to watch the Olympics in Japan, real time.

So no, the idea that we would expand our communication ability and that electronics would get more portable, as in the DT watch, were nearly givens.

The truth of the matter is that fossil fuels will not last forever, man will have to diversify.

Newsflash, IC cars can run on non-fossil based fuels and H2 or CH4 based Fuel Cells are more likely to be a more likely long range solution than EVs.

Perhaps wide scale affordable electric vehicles will not happen in our lifetimes, but one thing I am sure of is that it will happen. Why, because we have no other choice.

Cost being the key issue.
Clearly IF the cost of electrical storage comes down then EV sales will rise.
No one doubts that, but then there is nothing that assures us that will be the case either.
Storge density has gone up but storage costs have not really come down.

And as shown before, of course we have other choices.
H2, Bio-fuels and CH4 are all long term prospects.

The solutions we come up with are not limited by your imagination.