Electric Car? How about a Compressed Air Car?

Roger (K8RI) wrote:


My wife has a Prius which is a bit over a year old. I remember the
sticker EPA estimate was 50 mpg in town. I don't remember what it was
for highway but it was something like 5 % or so less.


I was just at the Toyota dealer this week driving a Camry hybrid. No
way I get a Prius for a number of reasons. Real world driving in the
Camry gets you about 36-40 MPG in the city. For highway driving you
need to specify at what speed to make your comparison with other cars.
At 80, which is a very typical speed here, you get 35 MPG, no wind. The
wind plays a big factor, just like with my full size van and pickup.
With a 20 knot tailwind at 80 MPH I was seeing 40-45 MPG. Into that
wind I was seeing 30 MPG. Very impressive car. Fully loaded it is
$30K. If in your city traffic causes you to drive at 20 MPH or less
then you have an all electric car because you can do that without the
gas motor starting.

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote:

Small diesels give about the same fuel economy as hybrids, but the
diffuculty is making the tailpipe emission standards in the US -
particularly California. Thus the popularity of hybrids in the US but
not in Europe where emission standards are easier.

Actually, the emission standards are tighter in Europe. The reason they
can meet their emission standards with diesel engines is that they mandated
low sulfur fuel several years ago, and it is has an even lower sulfur
content than the ultra low sulfur fuel recently mandated in the US.

Where sulfur enters into things is that it fouls catalytic converters. By
eliminating the sulfur, converters can be used in the exhaust system to
reduce the amount of NOx and particulates, which are the two primary
pollutants from diesel engines.

Now that we have low sulfur fuel, a number of European manufacturers intend
to export their diesel car technology to the US. Expect to see new diesel
models that will even meet California standards, from companies like VW in
the new year.

"Newps" wrote

I was just at the Toyota dealer this week driving a Camry hybrid. No way
I get a Prius for a number of reasons. Real world driving in the Camry
gets you about 36-40 MPG in the city. For highway driving you need to
specify at what speed to make your comparison with other cars.

I'm not sure which of the reasons you gave are the reasons that cause you to
say that you would not get the hybrid Camry.

Are you saying that it is not enough improvement for the cost, or what?

I'm just curious. Thanks.
--
Jim in NC

"James Robinson" wrote

So, if I apply the brakes at 60 mph to get a 5 mphps deceleration rate,
then on a Prius, I would be capturing (1.8)/5 or about 1/3 of the
available energy in braking. At 40, it would be about 1/2 of the
available energy, and below about 20 mph, I would be able to capture all
of the energy, until the system dropped out at 7 mph.

Given that most of the energy to be recovered is at high speeds, then the
above suggests that if I drove the car, I would only recover between 1/3
and 1/2 of the available braking energy.

If someone less aggressive drives the car and has a very light touch on
the brake pedal, they might be able to capture a good proportion of the
energy.

In any event, as I suspected, the amount of energy that can be recovered
from the regenerative braking system is limited. You also have to take
into account the efficiency losses in the charge/discharge cycle, meaning
that even less of the recovered energy can be used on the power side.

I can tell you spent a fair amount of time composing that post, and doing
some figuring, so good for you. You seem to have a pretty good grip on some
numbers, I think.

I think that you should not get hung up on the braking issue, though. To
me, if it recovers any energy from the brakes, that is all gravy. There are
too many good things to look at, to knock it out of contention, because of
that one issue.

I know that there are some problems with the technology, as it exists, now.
It does appear to work pretty good, though. The GM offering looks like it
may be able to take the concept one notch better.

Many vehicles have had their specs "optimized" in the past. Airplanes,
cars, it doesn't matter. It is fairly common. That does not make it right,
though. I would be surprised to see the figures off more than ten percent,
though, from real world driving.

There are still problems with the pollution shifting to another place (power
plants) and in many places there is not enough capacity to prop up much of
an electric fleet. I know, but perhaps it will be enough for the public to
realize the need for more capacity, and do something about it. Wishful
thinking, probably.

For some people, the electric cars will make great sense. For others, not
so much. It is hard to argue against the fact that greater production of
electric cars will bring advances in the technology of electric cars. It
will happen.

Most of all, I am encouraged by the first generations of real attempts at
widely produced electric cars. It is surely a step in the right direction.

For now, I'm happy to leave it at that.
--
Jim in NC

On Wed, 21 Nov 2007 10:43:50 -0500, Bob Noel
wrote:

In article ,
James Robinson wrote:

I have seen people quote average mileage numbers as low as 25 mpg in very

On the expressway ours will run about 46 MPG at 70 MPH. Faster than
that and it's down hill in a hurry, but there are no places around
here where we can legally go faster than 70. Most of the roads are 55,
but typical traffic moves 62 to 63. What ever it's moving, just stay
with it.

I can't imagine one getting 25 even in the coldest part of our
winters. Of course it's a small engine and cools quickly so maybe they
just leave it running out in the parking lot.
Of course if they drive the belt way around Atlanta where the off
ramps are running about 65, the center two lanes about 80 and who know
what the through lanes are running. It was fast enough I was
uncomfortable in a Trans Am with a Corvette engine.

The early Prius did not get as good a mileage as the present ones.

cold or hot climates, to over 55 mpg under ideal conditions. Some quote
consistent numbers of 35 mpg. So it seems that people can experience a
great spread of fuel economy with the car.

Some things that adversely impact the per mile fuel economy of my hybrid:

1) ethanol in the fuel

Everything here is 10% ...so far.

2) New England winters (the engine runs much more often to stay warm)
it should only run if the battery needs charging or it needs extra HP
for the moment. Even in the winter if we don't let it warm up the
engine doesn't start until after the garage door has opened and we are
half way to the road. it seems strange to back out of the garage and
then the engine starts, or pull out of a parking spot and start down
the he street before it starts.

We actually let it warm up in Michigan winters and use the air
conditioner a lot in the summer and have still been running about 47.
Admittedly that is only after a bit over a year and a half.

3) short trips

On short trips (5 or 6 miles) it does very well

However the car is extremely sensitive to driving technique and winds.
Jackrabbit starts with full throttle to highway speeds and mashing on
the brakes at the next stop really kill the mileage.

Gentle starts (no you don't have to take a mile to get up to 55) and
light braking seem to be the best combination. Light braking seems to
be the key. The regenerative braking appears to work, but not when
it's mainly maximum effort stops.

There are clubs that are experimenting with unmodified cars running
contests using driving technique. There was a program (Discovery
Channel...I think) where several of the members using the Toyota Prius
did well over 100 MPG. I think the winner was 128 MPG. Of course they
were using driving techniques that would never fit into normal city or
hill country driving without getting the driver shot:-))

Setting the cruise control in hills is hard on the mileage. You let
is ease up the hill while gently slowing and then let it gain speed
coasting, or slowly accelerating down hill. That is where it really
shines.

Roger (K8RI)

On Wed, 21 Nov 2007 09:18:56 -0600, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote:

Roger (K8RI) wrote:

The Toyota Prius has the capability of running all electric in Europe.
There's a big button on the dash to put it in the all electric mode.
That makes them capable of over 100 MPG. Without it we seem to be
averaging a tad over 47. That option is not available in the states
so they could push the warranty up on the battery. In town and out in
the hills it's possible to get much better than the rated 50 MPG, BUT
to use the driving techniques required to get that kind of mileage
would make you the target of everyone else on the road:-))


Not to be a smart ass but wouldn't putting it into all electrice mode make
the car go INFINITY mpg?

It would if they ran all electric all the time, but the battery pack
isn't that large. Normal mode to get to town and then drive around
town using all electric. Also at present the electric power is much
cheaper than that derived from gas.

Still a realistic mileage would require recording the KWH used for the
miles driven.

Figure the HP required to maintain 50 or 70 MPH, multiply by 0.746 to
get KWH and multiply that by your electric rates. The results should
come out with the gas costing 50 to 100% more for an hour at a given
speed IF your electric rates are 10 cents per KWh as they are here. In
California it's probably cheaper to use gas. :-)) OTOH if your car
already gets 50 MPG there is little if any savings by going to
electric. A Prius in California would probably cost half as much to
drive as an electric car. The problem is making these kinds of
comparisons requires a LOT of assumptions.

It's like solar panels in the SW where they see paybacks in only a few
years and that is with some hefty subsidies. Here in Michigan we
receive so little sunlight on average we aren't even on the payback
charts which only go to 20 years and we receive no subsidies for solar
installations.

Roger (K8RI)

In article ,
"Roger (K8RI)" wrote:

3) short trips

On short trips (5 or 6 miles) it does very well

I have a Mercury Mariner hybrid which is based on Toyota hybrid drive
technology. Since I don't have an option of not running the engine, short
trips are where it does the worst for mileage, especially in the winter.

--
Bob Noel
(goodness, please trim replies!!!)

On Wed, 21 Nov 2007 17:39:17 GMT, Larry Dighera
wrote:

On Tue, 20 Nov 2007 20:50:55 -0500, "Roger (K8RI)"
wrote in
:

As has been publicized, we don't have the grid capacity to support
much in the way of all electric cars. The same is true for Hydrogen.
It's either produced from fossil fuels with a lot of polluting
byproducts or takes a whale of a lot of electrical energy to produce
from water.

When/if worldwide photovoltaic production ever meets consumer demand,
you are going to see an enormous increase in solar power
installations, not only in commercial buildings, but residences as
well. Today, the excess electricity generated by a home's
photovoltaic power generating system is used to turn the electric
utility meter backwards. As electrically powered vehicles become more
mainstream, that excess solar power could be used to directly charge
vehicle batteries or for hydro-electrolysis to generate hydrogen gas
for fuel.

This doesn't change the lack of grid capacity. Ask the State of
Wisconsin which has a large wind farm. The state agreed to purchase
any electricity the grid couldn't handle. It's costing them many
millions of dollars.

We don't have the economically viable technology for all electric
vehicles to have enough range. Generating H2 with the excess energy
sounds good, but how do you generate and store enough if you don't
live in the SW?


Side benefits of residential solar power generation are the peace of
mind inherent in the redundancy of distributed (as opposed to central)
power generation and the resulting robustness against massive power
outages due to a cascade of equipment outages triggered by a
single-source failure, the ability to "thumb the eye" of oil
robber-barons, the reduction in the production of pollutants,
insurance against the inevitable increases in the price of energy, and
virtue of abandoning 19th century technology for a more enlightened
solution.

It comes down to economics and geographic location. My daughter's
husband is a consultant in the business. We sat down and figured a
hybrid system of both active and passive solar would cost me close to
$50,000 up here and unlike California we receive no subsidies for
either active or passive solar panels.

Price photovoltaic panels per KWH. The price without a subside is
enough to scare most any one off.


Alcohol is an interim solution with the hybrid being by far the most
economical and quickest to implement of the interim solutions.

As for grid capacity we are rapidly coming to the point of real time
usage monitoring with remote setback of heating and air conditioning.
Here with peak rates of about 10 cents per KWH we wouldn't see the
savings of those fortunate souls paying 38 cents during peak demand
out in the Republik of Kalafornia.

OTOH solar panels don't do us much good either.

Why? Photovoltaic panels are able to convert infrared isolation even
on cloudy days.

But that ain't much power out. it's only a small fraction of what you
get in direct sunlight and solar panels are not all that efficient at
best. Also we're 43'37" N and the days are several hours shorter up
here than in say Georgia or even California. Also you can see the
power drop due to clouds, or just due to dust and dirt collecting if
you don't clean them every couple of weeks. They also age so it's not
a one time cost. Efficiency is going up, but electricity from solar
panels is still about 3 to 5 times the cost of that from the power
grid in areas where sunlight is plentiful and the atmosphere is seldom
cloudy. Here with 10 cents per KWH and we have about 3 days a month
without some clouds it's probably more like 5 to 7 times.

And even when they do get the cost down and I expect they will, the
power grid is still limited as to the amount they can buy back (or
handle) When that point is reached the payback for power into the grid
will drop and at times they may not even accept power. As I mentioned
the wind farm in Wisconsin and their problems.

There is a Silicon plant near here that is multiplying their capacity
several times over and they just finished doubling the size of the
plant. The amount of pure Silicon coming out of there is staggering.
Wafer size has gone from 1/2 to 3/4 of an inch when I started in the
industry to a current of 14 inches or there abouts. Still the waste
of making wafers from silicon rods is over 50%. Considering it used to
be on the order of 80 to 90% that's pretty good. Many years ago when
loss was much greater they developed some new sawing techniques that
cut the waste in half. it was still tremendous, but the increase in
yield almost caused several of the suppliers to go out of business.
One did.

We still have a long way to go before solar cells become economically
viable except in some select areas.

Roger (K8RI)

"James Robinson" wrote in message
. ..
"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote:

Small diesels give about the same fuel economy as hybrids, but the
diffuculty is making the tailpipe emission standards in the US -
particularly California. Thus the popularity of hybrids in the US but
not in Europe where emission standards are easier.

Actually, the emission standards are tighter in Europe. The reason they
can meet their emission standards with diesel engines is that they
mandated
low sulfur fuel several years ago, and it is has an even lower sulfur
content than the ultra low sulfur fuel recently mandated in the US.


They run a different cycle in Europe.

I've worked on vehicles to meet both the Europian and US certification
requirements. Europe is easier.

Where sulfur enters into things is that it fouls catalytic converters. By
eliminating the sulfur, converters can be used in the exhaust system to
reduce the amount of NOx and particulates, which are the two primary
pollutants from diesel engines.


Correct. The problem with NOx is that it is hard to reduce (de-oxidize) in
the presense of O2. Lean NOx catalysts just don't have the efficiency
required to meet the California standards. NOx traps require that you inject
fuel into the exhaust to reduce the stored NOx every few minutes.

Selective Catalytic Reduction using Urea injection should start showing up
in the US soon.

Now that we have low sulfur fuel, a number of European manufacturers
intend
to export their diesel car technology to the US. Expect to see new diesel
models that will even meet California standards, from companies like VW in
the new year.

You will be seeing stuff from a number of companies in the near future.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Bob Noel" wrote in message
...
In article ,
"Roger (K8RI)" wrote:

3) short trips

On short trips (5 or 6 miles) it does very well

I have a Mercury Mariner hybrid which is based on Toyota hybrid drive
technology.

Not really.
Ford traded some patents with Toyota since each company got to the patent
office first with some technologies. Toyota then got to the press first
claiming that Ford was using the Toyota technology - they forgot to mention
the Ford technology that they needed....

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.