Actually, I found one use for it.
I was driving my old XJS up to workshire with my daer old whte haired
mum in teh passeneger seat.
She glanced across at teh rev counter and said 'are we doing 50 mph
dear?' as she looked at the tacho on the 5000 RPM mark.
I will leave you to work out what 5,000RPM in top gear on an XJS was, in
terms of road speed :-)
Yes. Cars ARE in fact insulated very well. You only need to take a ride
in e.g. my old series III landrover woith nowt but a sheet of aluminium
between you and the elements to see how MUCH insulation a modern car has
Most cars have something like 1/4" of fibre and carpet on teh floors,
the rear seats line that part of the car, and the doors usually have a
2-4" aiorgap in them. Dreaughts are of necssity totally absent by and
large, and roofs are normally lined with headlining and again about 1/4"
of insulation. some cars even have double glazed windows.
Even with a U value of about 5 - equivalent to a totally single glazed
car, and a square meterage area of - what - 16 sq meters of cabin, that
is 80W per degree C differential, so AT WORST for -5 outside and 25C
inside, it only needs 2.4Kw to heat it. In practice that is a fairly
ludicrous U vcale, becaseu teh glass is thicker than window glass, and
most of the cabin is well insulated.
Lets face it, a lining of 15mm celotex is not going to cost very much.
And there is going to be a wedge of batteries and electronics under the
floor kicking out a hundred watts. Getting heat from the motors - if
thse are ouboard on the wheels - is not so easy, but even there, if
wound with pipe istead of solid wire, the heat could be removed bu
circulatng coolant through them..
The total power needed to run our car at - say - 30 mph, is about 5kW.
At least 5% of that is likley to be wasted as heat - say 250W. That is
potentially available to heat the car without losing anything.
I would not think that more than another 2-300W would be needed to heat
the car in any circumstances. So yes, there is enough energy. Maybe the
heater and/or aircon would knock the range down 20%, but it does that on
a normal car anyway.
No it's not! everything I've written above is true. Ignoring the data, if
you simply look at the petrol consumption of ,say, a 1600cc car 30 years ago
( about 26mpg) and compare it with a modern engine ( about 40+mpg) you will
find significant improvements in efficiency which also does relate to the
pollution produced, even without catalists in the exhaust system. The fact
that these modern cars also have much more inside them consuming power
proves my point further.
Probably due to the significant rise in the use of Diesel engines (in cars)
which produce lots of small particules (soot) which get into our lungs and
clog them up. Particle Traps are on their way to cure this problem, I think
it's one of the French manufacturers that is already installing them. I too
have developed Asthma in the last 10 years.
Nobody has pointed out a flaw at all, to me they just show they don't know
about Fuel Cells, their possibilities, uses and how fast the technology is
advancing so there is little chance of agreement on this topic.
Oh, and with power stations also going over to the use of Fuel Cells
pollution from them will reduce too. :-)
It is, but out of context and with little relation to the big picture.
Because there have been minor improvements in a flawed highly inefficient
piston engine design over the past 30 years, you appear to think this
exonerates the internal combustion engine, or it is efficient or clean or
something. It is NOT.
The engine it at the end of its lifespan, it should have gone 50 years ago.
As I mentioned in another post, according to MIT the fuel cell is not viable
yet for vehicles, which are the world's worst polluters.
Far more efficient Rotary and Stirling diesel and petrol units appear the
best options to fill the gap. The Stirling is external combustion, which is
much a clean on the burn. Even the Rev Tec Aussie engine, a piston engine,
improves thermal efficiency from 25% to over 50%.
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What you have failed to realise, is that even these are only stopgaps too.
At the very best, a fuel BURNING engine delivers only 60%
efficiency - maybe a little more. The rest is waste heat.
If you had goine to a snotty uni, where the theory is taught, you would
understand that any heat engine - and all the above are heat engines -
has its efficiency dictated by the ratio of the temperature of burn to
the echaust temperature. Especially as that is why a 'condensing boiler'
is built the way it is.
The big picture is about energy conservation, especially in terms of
waste heat, and the irreversible (in the short to medium term) problem
if taking fossilised carbon out of the ground and pumping it into the air.
To solve that you need to
- use less.
- burn plants you grew last year.
- generate power by means that don't generate waste heat OR
- use waste heat to replace the use of fuel elsewhere (CHP)
Use of the engines described does not solve any of these apart from, in
a minor way, the first.
Fuel cells can solve many of the above, but in the end. electricity is
bets because it generates very little waste heat when used to generate
The issues then become how to generate electricity without using fossil
fuel and/or heat engines. Feul cells are not heat engines, but usually
use fossil fuel. Nuclear power doesn't use fossil fuel, but does use a
heat engine. windmills do neither, but are ugly, of variable power, and
woefully inefficient in terms of space used. Water and wave power does
neither, but is localised as to its applicability. solar cells are even
ore woefully inneficient, but there mat be better technology coming..
burning domestc rubbish and biomass is good as it doesn't use (much)
fossil fuel - i.,e. it's more or less carbon neutral, but it does tend
to need treatement to reduce pollution of toxic flue gasses.
There is no easy answer. But simply slightly better heat engines
burining fossil fuils are almost the worst of all possible answers.
It is obvious that I know that, as I have already said that.
Not quite right. The overall mechanical efficiency of the unit has to be up
to it. Also in road engine, the power to weight ratio is one of the most
..and use less fuel cleanly.
I did say in the short to medium term the diesel and gasoline engines will
have to do, but there are far more efficient versions around than the
abomination we all currently use.
It is the loses at generation and transmission losses. This can be reduced
by having smaller local power stations, the UK had, using natural, using CHP
to heat the local district. Transmission losses then are low and overall
energy efficient is very high. Sweden do this.
"woefully inefficient in terms of space used"? You see cows grazing under
them. They can be in the middle of fields and only occupy a small footprint.
There are windmill farms being built off-shore all over the UK right now,
Out of sight.
Wet solar panels generally inefficient per squ foot, but have the whole of a
south facing roof being a solar panel and the by shear size you have an
efficient collector, that will virtually provide all of the houses needs if
you can store the heat in a large thermal store
Put PV cells on every south facing roof and most of the power generation
station will not be needed. The solutions are there. It needs political
will to force it through.
On the domestic and commercial build front, insulation levels to
superinsulation, passive solar design of homes, as Germany as doing with
Passiv Solar regs, south facing roofs having integrated wet solar/PV cells,
boiler with integrated CPH elec/gas Stirling boilers and soon to be
introduced. The Stirling CPH boilers cut the peaks of electricity usage.
All this is right now, and can and should be implemented. Doing so will
drastically cut fuel usage and emissions and prevent fuel poverty. And more
efficiency is on the way...
What looks promising and appear likely to be introduced is the Zeolithe heat
pump, which runs on natural gas for the provision of domestic heating and
hot water. Currently these units are floor mounted and resemble a typical
boiler in appearance. Zeolithe heating appliance's use less energy and are
more environment-friendly than electric heat pumps and gas boilers. It
provides considerably higher output levels than the current conventional and
condensing boilers. Carbon-dioxide emissions are reduced by approximately
20 to 30%.
On the vehicle side, matters are more complex. Of course, local CHP power
stations drip charging electric car overnight is very sensible, but we do
not have the infrastructure for this, as yet. Also what do you do in a
city, when you car is parked on the road? How do you charge it?
There are far more efficient diesel and gasoline engines around, and are
running. These can be developed fully and integrated into a hybrid setup.
Another method suggested is waste heat from an advanced rotary engine (not
an inefficient Wankel design) which has well over 50% efficiency, driving a
small Stirling engine from its waste heat, which drives a compressor, which
charges an air tank. The compressed air assists drive via an air motor in a
hybrid setup. This is a fine stop gap, and around town the car can run on
non-polluting air, which is generated from what would have been wasted heat.
The whole setup can be small in size as rotary engines are small and a
compressor/air motors is also small. The compressor can also be the starter
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Hang a cable out of the window, or *gasp* build undergroung parking
areas with electrical sockets?
Or charge them up in supermarket car parks etc etc.
You CAN fully charge a lithium car in about an hour, but you need
specailsed charging facilities to do it safely.
Sadly these would require huge changes in engine factories, costing huge
amounts of money.
hugely complicated and expensive.
You could simply have a smaller engine that charges the batteries.
If you're going to build underground car parks for all city cars that
haven't their own off road parking, wouldn't it make much more sense to
spend the money on extending the tube network and making it cheap/free?
An electric car is only suitable for city use and will do nothing for
I only go to the supermarket on a day when I can be in and out in an hour.
Apart from the fortune needed to buy and replace such a battery for car
*Why is it that doctors call what they do "practice"?
Dave Plowman firstname.lastname@example.org London SW 12
That is simply not so.
With 300 mile range and potentially one hour fast charge from flat, it
would be ideal for rural use and commuting.
What it won't do is 16 hour 1000 mile journeys...
Yes. That is the only issue left IMHO. But I would suspect you would not
replace all teh battery - simply those cells that were below standard.
That would essentially be the major part of every 'service'
If you add 'potential' to that I might believe you. Non of the electric or
hybrid vehicles I've read about being tested in real world conditions get
near their claims of range, etc. And a one hour charge rules out lead acid
batteries - so the cost of alternatives is presently prohibitive.
Well, nor will any petrol car I know about without re-fuelling. And anyone
doing such a drive should have a couple of breaks anyway.
*Windows will never cease *
Dave Plowman email@example.com London SW 12
Not so. Things have really moved on in the last year or so. To the point
where there is at least one company brave enough to have built a lithium
polymer powered test car and be offering cell packs for sale. They have
repacakged the biggest they could find with safety circuitry and the
tests they came up with were close enough to my predictions for me to
feel they were not avaiting porcines.
Price is still an issue - the sort of stuff I buy retails at $3 per watt hour,
so 50kWh is $150,000
Thst for torch battery sized stuff. That represents a sort of 'it won't
cost more than that' level. A hand built racing engine costs thet much
as well, and no one says that because a Cosworth F1 engine is 100 grand,
thats waht a Ka should cost as well..
No, but the problem is the one hour minimum to completely refill its 'tank'
Here are some links
This one is already 9 years old but predicts todays performamnce figures
Heres the record holding electric car for teh Pikes |Peak run
Here is a company that can acatually supply 35kWh batteries for
cars...tho there is a whiff of bovine excrement about his one.
heres some data from a 1998 conference that pretty much says the same
thing I have been saying.
Ah. I found the one site I was looking for
This is a mean machine.
Yes,indeed, it would. It is, I agree, a more realistic target than
breeding flying pigs.
2) The petrol used in 300 miles by a typical modern car contains
about 1 GJoule. If we assume a factor of two higher efficiency, then
charging in an hour needs 140 KW. A standard domestic power circuit
is rated at 7 KW. You have a factor of 20 to make up.
Dammit, a CYCLIST will expend some 20 MJoules in 300 miles. Recharging
that in an hour needs 6 KW! There is NO WAY that you will design a car
to be as efficient as a cyclist, despite the motor lobby propaganda.
2) Despite claims, such devices would NOT help with congestion to
a detectable degree.
You need specialised facilities to charge the damn things at all, at
any rate. The necessity for fancy protection mechanisms is one of the
reasons that they are expensive.
Please could you take this stuff to a newsgroup (a) where people are
knowledgable about this sort of thing and (b) where it is on group?
I never said you would use the domestic circuit to fast charge. The
scenario was a 'fats charge' station like a petrol station where you
could plug in, have a pee, have a coffee, and come back with a more or
less charged car in under an hour. Typically you would NOT run the thing
totally flat - more like do 200 miles and then wait 40 minutes to charge it.
I am not going to repeat the figures, but I and someone else came up
independently with 9/10 hours at 20A to do the charge. That would mean
essentially 200A or 50Kw to do the one hour charge. I am not sure where
we differ between 50Kw and 140kW. My figures derived from taking the
shaft bhp used on a normal run, and electrifying those: The figures were
borne out by an actual test car that is running.
Ah. You have assumed a factor of two efficincy. I think that you should
be looking at 3 or more for a start. Petrol engines are not markedly
effuicient at part throttle. Transmission and ancillary sttuff
(alternator and other takeoffs - colling fans etc - sap more). They are
0% efficient sitting at traffic lights whereas electric motors can be
Well I dunno about cyclists. My figures were for about 50kWh (180MJ) for
the 300 miles. And those figures are borne out by other test sites I
found - no I haven't got them to hand because it arose in another
discussion elsewhere. Might be able to dig them up if you are
interested. ireckon a cyclist ambling along at 15mph might need about a
horsepower.. 750W - and would take 20 hours. That's 15KWh or 55MJ? yeah.
within the same range as you. For a back-of-the-envelope calculation.
If we take say 60mph as the average speed, its a 5 hour trip averaged at
10Kw, or about 15bhp. That seems eminently reasonsable for something
like a Fiat Punto - 50bhp - run at on average 1/3rd throttle. I am
assuming better than 90% conversion efficviency, because that is what a
decent electric motor, cells and controller can do. These are not fairy
No one said they would. what we are aiming for is almost zero pollution
at teh point-of-transport, and utilkisation of an existing electricity
infrastructure, especailly use of off peak electricity, which allows for
better efficiency of generation anyway.
Congestion can only be reduced by either dramatically raising speed
limits, or taking cars actually off the road.
Nothing too fancy is needed. A simple voltage and temperature monitor is
all that is required.
Currently the ones being developed for model use are about 30% of cell
cost - a few dollars only. How this would scale with larger cells is
unknown. Its the last area to investigate.
Well you seem to think YOU are, and so does IMM. AND I think its is
interesting enough to stay here until it dies of boredom.
Its no more YOUR group than it is mine. Its marginally nearer on topic
than 'britney spears nude'
What ??? I can't imagine a human being able to develop a horsepower
for very long at all - more like 100 or 200 watts and even that would not be
sustainable for long. So how does the average "regular" cyclist ride a bike for
an hour or so at 15 mph covering 15 miles ?
Followups set somewhere more relevant.
|> |> >>>An electric car is only suitable for city use and will do nothing for|> >>>congestion.|> >>>|> >>That is simply not so.|> >>|> >>With 300 mile range and potentially one hour fast charge from flat, it |> >>would be ideal for rural use and commuting.|> > |> > Yes,indeed, it would. It is, I agree, a more realistic target than|> > breeding flying pigs.|> > |> > 2) The petrol used in 300 miles by a typical modern car contains|> > about 1 GJoule. If we assume a factor of two higher efficiency, then|> > charging in an hour needs 140 KW. A standard domestic power circuit|> > is rated at 7 KW. You have a factor of 20 to make up.|> |> I never said you would use the domestic circuit to fast charge. The |> scenario was a 'fats charge' station like a petrol station where you |> could plug in, have a pee, have a coffee, and come back with a more or |> less charged car in under an hour. Typically you would NOT run the thing |> totally flat - more like do 200 miles and then wait 40 minutes to charge it.
Well, excluding the minor detail that taking an hour to 'fill up'
where it currently takes 5 minutes is not something that I should
want to do, using a 200 A circuit safely or even practically isn't
like using a 13 A one. Even in industry, the maximum plug that is
used just like a domestic 13 A one is rated at 32 A.
Inter alia, contact corrosion, condensation and so on are BAD NEWS
at 200 A.
|> Ah. You have assumed a factor of two efficincy. I think that you should |> be looking at 3 or more for a start. Petrol engines are not markedly |> effuicient at part throttle. Transmission and ancillary sttuff |> (alternator and other takeoffs - colling fans etc - sap more). They are |> 0% efficient sitting at traffic lights whereas electric motors can be |> stopped altogether.
I was estimating on the basis of distance driving. 50 KW is too low,
except for the smallest runabout, which would not meet most people's
requirements. 100 KW is more plausible, even given your factor of 3.
|> > >|> > > Dammit, a CYCLIST will expend some 20 MJ in 300 miles. Recharging|> > > that in an hour needs 6 KW! There is NO WAY that you will design a car|> > > to be as efficient as a cyclist, despite the motor lobby propaganda.|> >|> > Well I dunno about cyclists. My figures were for about 50kWh (180MJ) for|> > the 300 miles. And those figures are borne out by other test sites I|> > found - no I haven't got them to hand because it arose in another|> > discussion elsewhere. Might be able to dig them up if you are|> > interested. ireckon a cyclist ambling along at 15mph might need about a|> > horsepower.. 750W - and would take 20 hours. That's 15KWh or 55MJ? yeah.|> > within the same range as you. For a back-of-the-envelope calculation.|> |> What ??? I can't imagine a human being able to develop a horsepower|> for very long at all - more like 100 or 200 watts and even that would not be|> sustainable for long. So how does the average "regular" cyclist ride a bike
|> an hour or so at 15 mph covering 15 miles ?
At 200 W.
The indirect transmision losses involved in shovelling large numbers of
loads of small amounts of fuel to thousands of small power stations all over
the country are vastly greater than the transmission losses in power cables.
I bet they have not looked carefully enough at the costs and energy
efficiencies of such a policy, unless they are in a position in which the
fuel is naturally available dispersed all over the country.
Sadly, incapable of producing anything more than a negligible amout of
You should not use such a meaningless term in a discussion which is more or
less scientifically based. Efficiency is defined as power out/power in.
There is no room for a subsidiary phrase "per square foot".
Unfortunately the economics are still wrong. Very wrong. Otherwise they
would have been in use by more than the afficionados.
You should not have a car if having one means the appropriation of public
highway space for your exclusive use.
Or do folk who misuse roads in this way pay rent to the local authority?
And how many folk are gong to be trained to be proficient in servicing such
a vastly complicated object?
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