"The Natural Philosopher" wrote in message
...
IMM wrote:

"The Natural Philosopher" wrote in message
...


As you may know, I have a little hobby.
Flying electric model aircraft.
Up to tow years ago there was no way
to even approach the power and
energy densities of a tank of fuel. There
is now. And its tipped the balance so that
applied to cars, it comes out damn near
equal overall in terms of power and range
to weight of a tank of petrol and what is
needed to make it turn the wheels..

I can buy all I need to use this
technology NOW.


So, electric cars are "equal" to petrol right now in range and
performance.


They CAN be. One allegedly is.


Apart from the zero emissions at point of use (brilliant as cities are
cleaned right up), what else is there to tip the balance? Generating
more
electricity (very dirty procedure at present) at power stations is going
to
produce more emissions. Cleaning this up is an expensive nightmare, not
to
mention the electrical distribution system for re-charging vehicles.



Yes, but the alternatives are worse. At least the potential to generate
electricty from non fossil sources exists: hydrogen cars still need
hydrogen, and have neither the range, nor indeed the possibility to
generate the hydrogen cheaply except by electricity. The battery wins
over the hydrogen car. Period.

Whatever is dirty in a power statin is dirtier in a car. If you can go
froim fuel to power in a car at a certain level ofeffciency, then
certainly you can go from fuel to power, and electricity at least as
efficiently and at least at same level of pollution in a power station.
In fact its possible to do better when the weight limitations of car
engines are removed.


Otherwise we would have to look at biofuels - methanol, biodiesl etc. -
and hope that the economics of production make more sense.

I don;t think they do.

Deserts are waiting to be farmed.


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"The Natural Philosopher" wrote in message
...
IMM wrote:

"Rod Hewitt" wrote in message
.. .

"IMM" wrote in
:


A car has no insulation, as they produce so much waste heat the
engines can provide enough even in the coldest conditions. Adding
insulation, bonded to the cars sheet metal around the cabin, would
improve matters. The drive motors and batteries produce heat, so this
must be available for use.


And also add to the cost and weight...


Insulation should not add that much weight. Cost? Mass production will
bring that down.


I doubt that any heat would be available from motors if they are fitted
into the wheel hubs.


If they are. Most electric cars have one motor.


There may be problems supplying enough electrical power for the
demisters,
seat heaters (oops, well I have a Saab), and other things (maybe needing
a
heater for the screen/headlamp wash and other currently
unnecessary/rarely
fitted devices).


Cars are full of unnecessary crap which add cost and weight affecting
fuel
consumption, such as rev counters. Why does anyone need to know how
much
the engine is revving in a normal road car? Beats me. I know when it
is
revving, I hear and feel it. If it is revved too much the management
system
cuts it out.


True. Fashion accessory.

An electric window on the drivers side is unnecessary too


IMHO its mandatory. Its the window you use the most in paying for
parking tickets, and pulling them out of silly little slots only to feed
them into other sily little slots later...not to mention tossing coins
into teh darford crossing machines. The ability to get it down, and up,
quickly, without doing more than touch a button is essential.

, as
are electric sunroofs, which are a British fascination. The French
don't
want to know them.


Did you know IMM that it has been calculated that the weight, ad cost,
of winding handles exceeeds teh weight, and cost, of electrically driven
windows and sunroofs?

No. I don't suppose you do.

Or that the loss in power due to aerodynamic compromise of an open
window in hot weather is greater than the loss due to using a modern
efficient aircon?

No, I don't suppose you do.


Or that the losses in colling an engine via teh viscous fan exceed the
losses in blowing hopt airt into te caboin in winter?

You probably could work tat one out..

I knew all them, and knew them before you.

Why isn't the a/c an absorption system using waste engine heat, instead
of
taking power off the crank, reducing mpg?

Because its low grade power, and would need a HUGE HEAVY installation to
get colling out of it.

In the US absorption systems were found to be viable in cars.

Its time you enlisted in a snotty uni and learnt basic engineering.

The sort of engineering I should engage in is demolition engineering, and
run bulldozers through Oxbridge, Eton, Harrow, etc. Then we will all be
better off.


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"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof, twice
the
area, and produce the same volume of solar hot water as the Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a 25Jw
one.

It is not. Solar collectors produce hot water. Some produce more than
others for the same area, hence more efficient for a given area.




No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

Are you saying that for a given solar collector, if you have two
installations of _the identical model_ but with installation X having a 1sq
m area but Y having a 2 sq m area, then because installation Y has an output
that is twice that of installation X it is necessarily twice as efficient?

No?

Well, that is the implication of quoting a bogus specification like
"efficiency per square metre".


Or to put it another way. I have installation X which is 1 sq m and I can
calculate it's efficiency is 60%. The efficiency of installation Y is still
60%. It has twice the input power, but also twice the output power.



--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof, twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is limited on
a roof. Solar panel X can be more efficient (ratio of converted power out
to power in) than panel Y. But panel X may take up four times the area of
panel Y. It means eff all if the area is not taken into account. For a
given area which is the most efficient? Area, area, area.




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"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is limited
on
a roof. Solar panel X can be more efficient (ratio of converted power
out
to power in) than panel Y. But panel X may take up four times the area of
panel Y. It means eff all if the area is not taken into account. For a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.






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"IMM" wrote in message
...


No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is limited
on
a roof. Solar panel X can be more efficient (ratio of converted power
out
to power in) than panel Y. But panel X may take up four times the area of
panel Y. It means eff all if the area is not taken into account. For a
given area which is the most efficient? Area, area, area.




Have removed the x-posting to u.r.g so as not to inflict them further with
this ridiculous thread. Wish I'd never asked about bloody lichens and
mosses now.

This is simple.

So X is more efficient (ratio of converted power out to power in) than Y.
But it takes up 4 times the area. Therefore it has four times the input
power, as this is directly proportional to it's area (radiant energy from
the sun is some number Watts per Square Metre).

IF X is 4x the area of Y, AND it is more efficient, then it must necessarily
output more than 4x the output power of Y.

If it does not, and you are saying that X requires four times the surface
area (and therefore four times the input power) that Y requires in order to
_output the same amount of power_ then it is not more efficient than Y, but
it instead has only 1/4 of the efficiency of Y.

Or to put this another way, if you had an installation of X and Y with both
the same area, X would only output 1/4 of the power of Y for the same input
power (being proportional to the area). Once again, X is only one quarter
as effiicient as Y.


--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk

"IMM" wrote in message
...

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as
a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is
limited
on
a roof. Solar panel X can be more efficient (ratio of converted power
out
to power in) than panel Y. But panel X may take up four times the area
of
panel Y. It means eff all if the area is not taken into account. For
a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay
for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.






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Technically Richard's right. You keep switching your definitions.

Quote: Solar panel X can be more efficient (ratio of converted power out to
power in) than panel Y snip For a given area which is the most efficient?
Answer: Obviously panel X. You said so yourself.

Quote: panel X may take up four times the area of panel Y
OK. So you could swap each panel X for four Y's in the same area. This
effectively gives you a large panel Y with the same area as a panel X and
all that matters is the relative efficiency.

But practically you are right as well - area is very important assuming the
area cannot be tiled by panels because it is too small. But, the efficiency
is still the same. Surely all you have to do is:

1. For each panel type, work out how many (if any) you can fit on the roof.
2. Multiply by the efficiency

Whichever gets the highest score will give you the most energy output from
your roof.

--
Martin & Anna Sykes
( Remove x's when replying )
http://www.users.globalnet.co.uk/~sykesm

"Martin Sykes" wrote in message
...

"IMM" wrote in message
...

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient
as
a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is
limited
on
a roof. Solar panel X can be more efficient (ratio of converted
power
out
to power in) than panel Y. But panel X may take up four times the
area
of
panel Y. It means eff all if the area is not taken into account.
For
a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay
for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.






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Technically Richard's right. You keep switching your definitions.

Quote: Solar panel X can be more efficient (ratio of converted power out
to
power in) than panel Y snip For a given area which is the most
efficient?
Answer: Obviously panel X. You said so yourself.

Quote: panel X may take up four times the area of panel Y
OK. So you could swap each panel X for four Y's in the same area. This
effectively gives you a large panel Y with the same area as a panel X and
all that matters is the relative efficiency.

But practically you are right as well - area is very important assuming
the
area cannot be tiled by panels because it is too small. But, the
efficiency
is still the same. Surely all you have to do is:

1. For each panel type, work out how many (if any) you can fit on the
roof.
2. Multiply by the efficiency

Whichever gets the highest score will give you the most energy output from
your roof.

--
Martin & Anna Sykes
( Remove x's when replying )
http://www.users.globalnet.co.uk/~sykesm




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"Martin Sykes" wrote in message
...

"IMM" wrote in message
...

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient
as
a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is
limited
on
a roof. Solar panel X can be more efficient (ratio of converted
power
out
to power in) than panel Y. But panel X may take up four times the
area
of
panel Y. It means eff all if the area is not taken into account.
For
a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay
for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.

Technically Richard's right.
You keep switching your definitions.

I don't.

Quote: Solar panel X can be more efficient (ratio of converted power out
to
power in) than panel Y snip For a given area which is the most
efficient?
Answer: Obviously panel X. You said so yourself.

Quote: panel X may take up four times the area of panel Y
OK. So you could swap each panel X for four Y's in the same area. This
effectively gives you a large panel Y with the same area as a panel X and
all that matters is the relative efficiency.

But practically you are right as well - area is very important assuming
the
area cannot be tiled by panels because it is too small. But, the
efficiency
is still the same. Surely all you have to do is:

1. For each panel type, work out how many (if any) you can fit on the
roof.
2. Multiply by the efficiency

Whichever gets the highest score will give you the most energy output from
your roof.

--
Martin & Anna Sykes
( Remove x's when replying )
http://www.users.globalnet.co.uk/~sykesm




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In uk.d-i-y, RichardS noaccess@invalid wrote:

This is simple.

It is. There's a universally-agreed on meaning of the word "efficiency"
in its technical sense. But our resident eccentric, IMM, will insist on
treating it as a synonym for "effectiveness", "utility", "fitness for
purpose", or a slew of other terms. He will (on all past form) refuse to
back down on terminology; if you're not careful he'll accuse you soon of
having been blinded to the iniquities of land taxation and word abuse by
your time at a snotty Uni.

Please don't feed the trolls. Benign neglect is working reasonbly on the
oh-so-humourous cross-posting brigade. Even the wish to not leave Google
/dejanews history uncorrected is served better in the long term by
removing the encouragement to polemic which answering IMM provides.

Just walk on by. This is not the thread you're looking for. Nothing to
see here, folks, Move along. Move along. They'll turn to rock when the
sun comes out. Move along.

wrote in message ...
In uk.d-i-y, RichardS noaccess@invalid wrote:

This is simple.

It is. There's a universally-agreed
on meaning of the word "efficiency"
in its technical sense.

Which is lacking.

snip inane babble


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wrote in message ...
In uk.d-i-y, RichardS noaccess@invalid wrote:

This is simple.

It is. There's a universally-agreed on meaning of the word "efficiency"
in its technical sense. But our resident eccentric, IMM, will insist on
treating it as a synonym for "effectiveness", "utility", "fitness for
purpose", or a slew of other terms. He will (on all past form) refuse to
back down on terminology; if you're not careful he'll accuse you soon of
having been blinded to the iniquities of land taxation and word abuse by
your time at a snotty Uni.

I was waiting for some bizzare twist of logic and relevance to come from
IMM, but we were spared of that! Not sure that a Northern Redbrick (however
accomplished) quite qualifies for the usual vitriol from IMM. I'm sure I'll
be proven wrong on that score soon, tho.

Perhaps the motto I ought to remember is to never argue with a fool. They
bring you down to their level and then win on experience....


Please don't feed the trolls. Benign neglect is working reasonbly on the
oh-so-humourous cross-posting brigade.
(I don't see those posts, excepting when someone replies to them and drops
the xposts. Gonna drop a post in about NewsProxy at some point 'cos it's
doing sterling work for me in filtering out all of this crap)

Even the wish to not leave Google
/dejanews history uncorrected is served better in the long term by
removing the encouragement to polemic which answering IMM provides.

Just walk on by. This is not the thread you're looking for. Nothing to
see here, folks, Move along. Move along. They'll turn to rock when the
sun comes out. Move along.

ah, you beat me to it - this was pretty much my last post on the subject,
and even my usual morbid curiosity would have failed me had the thread
continued.

--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk

"RichardS" noaccess@invalid wrote in message news:4005525c$0$29495

Perhaps the motto I ought to remember is to never argue with a fool. They
bring you down to their level and then win on experience....

That is why I have backed out.




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In article ,
IMM wrote:
snip inane babble

Perhaps you'd consider trimming correctly your other posts?

--
*What boots up must come down *

Dave Plowman London SW 12
RIP Acorn

Dave Plowman wrote:

In article ,
IMM wrote:

Modern multi-braced roof trusses are cheap, and adequate, but won't
allow you to add a room in the attic like substantial victorian ones
might.


So? Modern timbers are far superior to Victorian houses.


It gets better and better....

It's all down to those new fangled polymerised timber trees they grow
now.... that where you get plastic wood from you know ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"IMM" wrote in message
...

"Franz Heymann" wrote in message
...

"The Natural Philosopher" wrote in message
...
Franz Heymann wrote:


So with a large area of Thermolux you might get to 200% more easily
than
with other panels?
Please, please understand that there is no such concept as
"efficiency
per
square foot" in either engineering or in physics. Efficiency is
usually
simply the ratio between the output power and the input power of a
system.



Actually that is not totally so. Efficency is a term that can be
applied
to more things than power.

For example, one could define the efficiency of a roof in terms of the
amount of water that runs off versus the total amount that falls on
it.


One can define an efficient business as one that has the highest sales
value, or margin value, per employee.

Efficiency is a measure of the efficacy against a theoretically
perfect
system,

That is the beginning of a circular argument.

of something doing the job it is designed to do. As normally
measured by how much it produces of the desired output versus how much
input it needs.

If we for example take solar energy, it is not menaingful to say that
e.g. civering every roof in lonbdon with a .3% efficient solar panel
is
inefficient, if the cost of so doing would actually be less than
building and running an equivalent power station over the same .
timescales.

One could argue that in terms of various resources one or the other is
more efficient.

The power station takes up less space, but uses more fossil fuel. The
electric panel is inefficient in overall thermodynamic terms, but
maybe
more efficient in the actual use of sunlight, since we don't have to
wait a couple of million years for the trees to turn back into
oil...The

power station has far less labour content involved, but perhaps uses
more materials.

uppose fo an instant that we cracked fusion power. Who cares about
efficiency, since the actual waste products - helium and heat - are
totally insignificant in a global context. At that point electcity
would
become the cheapest form of energy, subject to no taxes at all
probably,
and we would all be driving electric cars, and heating our houses
electrically, immediately :-)

Thanks for the homily.

I agree that in general usage, "efficiecy" is bandied around with gay
abandon. However, the discussion about solar panels was a
scientific/engineering one. To talk about "efficiency per unit area" in
such a context is pure nonsense.

What balls!

It is not balls at all. Two readers have tried to help you out of the
nonsense you have been speaking, but you appear not to have got the point at
all yet.
I reserve a part of a roof of 20ft x 10ft, 200 squ foot. I put in flat
plate collectors, I get n volume of solar heated hot water on a certain
isolation at a certain time of year. I put in the same 200 squ foot
Thermomax solar collectors. I get n x 2 volume of hot water on the same
isolation and certain time of year. For each squ foot of roof the
Themomax
is 100% more efficient. Is that clear?

Firstly, 100% of what?
Secondly, the number you quote is independent of the area of the panels,
the correct way of making the claim is to say quite simply "Thermomax panels
are twice as efficient as the flat plate units". That would be a precise
statement, incapable of being misunderstood than the incorrect way you have
been using for describing relative efficiencies.

Please believe me, an efficiency is only a ratio, and as such it is a
dimensionless quantity.
"Efficiency per square foot" is a meaningless concept, which can be misused
in the way I have now tried to show you at least four times.

I could use 400 squ foot of flat plate collector on the roof, twice the
area, and produce the same volume of solar hot water as the Thermomax
solar
collectors which takes up half as much square footage.

Absolutely correct. The Thermomax is twice as efficient as the flat panel.
You therefore need only half as much thermomax as flat plate to produce the
same power.

The area is "very" important in this instant. Is that clear?

As clear as daylight. The reason for the reduced area of Thermomax is that
it has twice the efficiency as the flat plate. *Not* that it has "twice the
efficiency per square foot".

Franz





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"IMM" wrote in message
...

"The Natural Philosopher" wrote in message
...
IMM wrote:

"Franz Heymann" wrote in message
...

"The Natural Philosopher" wrote in message
...

Franz Heymann wrote:



So with a large area of Thermolux you might get to 200% more easily

than

with other panels?
Please, please understand that there is no such concept as
"efficiency

per

square foot" in either engineering or in physics. Efficiency is

usually

simply the ratio between the output power and the input power of a

system.


Actually that is not totally so. Efficency is a term that can be
applied
to more things than power.

For example, one could define the efficiency of a roof in terms of
the
amount of water that runs off versus the total amount that falls on
it.


One can define an efficient business as one that has the highest
sales
value, or margin value, per employee.

Efficiency is a measure of the efficacy against a theoretically
perfect
system,

That is the beginning of a circular argument.


of something doing the job it is designed to do. As normally
measured by how much it produces of the desired output versus how
much
input it needs.

If we for example take solar energy, it is not menaingful to say that
e.g. civering every roof in lonbdon with a .3% efficient solar panel
is
inefficient, if the cost of so doing would actually be less than
building and running an equivalent power station over the same .
timescales.

One could argue that in terms of various resources one or the other
is
more efficient.

The power station takes up less space, but uses more fossil fuel. The
electric panel is inefficient in overall thermodynamic terms, but
maybe
more efficient in the actual use of sunlight, since we don't have to
wait a couple of million years for the trees to turn back into
oil...The


power station has far less labour content involved, but perhaps uses
more materials.

uppose fo an instant that we cracked fusion power. Who cares about
efficiency, since the actual waste products - helium and heat - are
totally insignificant in a global context. At that point electcity
would
become the cheapest form of energy, subject to no taxes at all
probably,
and we would all be driving electric cars, and heating our houses
electrically, immediately :-)

Thanks for the homily.

I agree that in general usage, "efficiecy" is bandied around with gay
abandon. However, the discussion about solar panels was a
scientific/engineering one. To talk about "efficiency per unit area"
in
such a context is pure nonsense.


What balls!

I reserve a part of a roof of 20ft x 10ft, 200 squ foot. I put in
flat
plate collectors, I get n volume of solar heated hot water on a
certain
isolation at a certain time of year. I put in the same 200 squ foot
Thermomax solar collectors. I get n x 2 volume of hot water on the
same
isolation and certain time of year. For each squ foot of roof the
Themomax
is 100% more efficient. Is that clear?

I could use 400 squ foot of flat plate collector on the roof, twice
the
area, and produce the same volume of solar hot water as the Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a 25Jw
one.

It is not. Solar collectors produce hot water. Some produce more than
others for the same area, hence more efficient for a given area.

No. Not more efficient for a given area. Just more efficient. The area is
irrelevant.
Some unkmeasured area of flat panel may produce 1 kW. The same area of
Thremomax may produce 2 kW. The thermomax is therefore twice as efficient
as the flat panel. The area you have used for doing the comparison is quite
irrelevant.

Franz

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is limited
on
a roof. Solar panel X can be more efficient (ratio of converted power
out
to power in) than panel Y. But panel X may take up four times the area of
panel Y. It means eff all if the area is not taken into account. For a
given area which is the most efficient? Area, area, area.

If the efficiency of a panel is 60% per square ft then, on the assumption
that you understand what physical dimensions and units are, the efficiency
of 1 sq.ft is 60%, the efficiency of 2 sq.ft is 120% and so on. I
suppose you realise now that you have hit on a method of producing perpetual
motion.

Let me ask a final question:

Given that, as you say, the efficiency is 60% per sq foot, what will the
efficiency of a set of panels covering 200 sq. ft be?
Note, I am asking for the efficiency of the whole set, not the "efficiency
per sq.ft", as you put it.

I take it that we agree that the efficiency is the ratio between the power
in the insolation and the power delivered to the heating system

Franz.

"IMM" wrote in message
...

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as
a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is
limited
on
a roof. Solar panel X can be more efficient (ratio of converted power
out
to power in) than panel Y. But panel X may take up four times the area
of
panel Y. It means eff all if the area is not taken into account. For
a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay
for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.

That was a trivial remark. Power transducers and transformers are usually
compared in terms of their efficiencies, amongst othe things

Franz

"Martin Sykes" wrote in message
...

"IMM" wrote in message
...

"IMM" wrote in message
...

"RichardS" noaccess@invalid wrote in message
...
"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof,
twice
the
area, and produce the same volume of solar hot water as the
Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient
as
a
25Jw
one.

It is not. Solar collectors produce hot water. Some produce more
than
others for the same area, hence more efficient for a given area.

No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

In this case it does. Area is the most important factor as it is
limited
on
a roof. Solar panel X can be more efficient (ratio of converted
power
out
to power in) than panel Y. But panel X may take up four times the
area
of
panel Y. It means eff all if the area is not taken into account.
For
a
given area which is the most efficient? Area, area, area.

Also, with solar panels the input doesn't really matter as you don't pay
for
it. The output per square foot, or metre (hot water generated), is what
matters. The efficiency of a boiler comes into the "ratio of converted
power out to power in", and is important as you pay for the fuel.






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Technically Richard's right. You keep switching your definitions.

Quote: Solar panel X can be more efficient (ratio of converted power out
to
power in) than panel Y snip For a given area which is the most
efficient?
Answer: Obviously panel X. You said so yourself.

Quote: panel X may take up four times the area of panel Y
OK. So you could swap each panel X for four Y's in the same area. This
effectively gives you a large panel Y with the same area as a panel X and
all that matters is the relative efficiency.

But practically you are right as well - area is very important assuming
the
area cannot be tiled by panels because it is too small. But, the
efficiency
is still the same. Surely all you have to do is:

1. For each panel type, work out how many (if any) you can fit on the
roof.
2. Multiply by the efficiency

Whichever gets the highest score will give you the most energy output from
your roof.

Qiute correct. And you did not need a mention of the spurious and
non-existent concept of "efficiency per square foot".

Franz

"IMM" wrote in message
...

[snip]

Technically Richard's right.
You keep switching your definitions.

[IMM says:]
I don't.

You do. You talk about "efficiency per square foot" and in the next line
you refuse to multiply the efficiency per sq ft by the area to obtain the
resultant efficiency.

[snip]

Franz

"martin" wrote in message
news
On Tue, 13 Jan 2004 22:10:07 -0000, "IMM" wrote:


"Franz Heymann" wrote in message
...

The radioactive contamination by a nuclear station is negligible,
despite
the protestations of the anti-nuclear lobby.

If every power staionin the world was nuclear we would be in big trouble
getting rid of the waste.

And even that contamination is
largely caused by irresponsible practices.

The human element. When it breaks down, big, big problems.

As is the case with flying machines.
There have been many more deaths due to aeroplane crashes than due to the 3
Mile Island accident.
Chernobyl does not count. That was as close as one can get to wilful
negligence.

Best forgot
nuclear as cleaner, lower tech alternatives are around right now.

But for how long will they last, and for how long can we tolerate their
insidious effects on the atmosphere?
I will venture a guess that many more people all over the world are this
moment dying from side effects of these lower tech alternatives than from
anything ascribable to nuclear power plants.

Franz

"The Natural Philosopher" wrote in message
...
Franz Heymann wrote:

"The Natural Philosopher" wrote in message
...

Martin Brown wrote:



Solar power works reasonably at latitudes below about 45 degrees, but
it
is quite frankly a complete non-starter at latitudes 55N and above.
Unless you count biomass conversion in forests for indirect fuel
generation.



Agreed. Horses for courses.

However tide power is not impossible either. Not an easy one tho.

If only we could get fusion power working...


Fusion power is going to turn out to be a great deal filthier than
fission
power.



I don't think so. The fisson products would all be relatively short
lived isoptopes, and teh main product is helieum. Non radioactve helieum


Its only the vast amounts of radiation intereacting with the shielding
that would cause some radioactive compounds to be generated.

No. In the reactions which are presently considered, there will be a lot of
tritium around. Tritium is a gas and it has a long half life. It scares
the pants off me.


Fission power is the cleanest and least polluting energy source ever
produced on earth.

Yes, I tend to agree with you.


The number of deaths per kilowatt hour which occur in the extraction and
processing of fossil fuels is a lot higher than the corresponding
number
for the extraction of uranium



I would not be surprised.


The pollution of the atmosphere by fossil fuel stations is vastly worse
than
the pollution caused by nuclear power stations.


That is certainly true.



The radioactive contamination by a nuclear station is negligible,
despite
the protestations of the anti-nuclear lobby. And even that
contamination is
largely caused by irresponsible practices.



Yes, the arguments are kind of curious:-

"We mustn't use nuclear power because the waste it generates might after
a few hundred years cause a little environmental change in certain deep
caves or the bottom of the ocean, so we had better stick to natural gas
and oil and coal, which are running out, are absolutely known TO BE
causing MAJOR environmental impact, and WILL DEFINITELY affect the WHOLE
HUMAN RACE in a few years, extremely adversely".

The real reason is probably to limit the suppies of enriched uranium in
case some gets into the wrong hands...


Franz

"Franz Heymann" wrote in message
...

"martin" wrote in message
news
On Tue, 13 Jan 2004 22:10:07 -0000, "IMM" wrote:


"Franz Heymann" wrote in message
...

The radioactive contamination by a nuclear station is negligible,
despite
the protestations of the anti-nuclear lobby.

If every power staionin the world was nuclear we would be in big
trouble
getting rid of the waste.

And even that contamination is
largely caused by irresponsible practices.

The human element. When it breaks down, big, big problems.

As is the case with flying machines.
There have been many more deaths due to aeroplane crashes than due to the
3
Mile Island accident.
Chernobyl does not count. That was as close as one can get to wilful
negligence.

Grow up!


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RichardS wrote:


Have removed the x-posting to u.r.g so as not to inflict them further with
this ridiculous thread. Wish I'd never asked about bloody lichens and
mosses now.

Its no use talking to IMM since the diodes went all down his left hand side.

IMM wrote:

"RichardS" noaccess@invalid wrote in message news:4005525c$0$29495


Perhaps the motto I ought to remember is to never argue with a fool. They
bring you down to their level and then win on experience....


That is why I have backed out.



^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

QED.

John Rumm wrote:

Dave Plowman wrote:

In article ,
IMM wrote:

Modern multi-braced roof trusses are cheap, and adequate, but won't
allow you to add a room in the attic like substantial victorian ones
might.



So? Modern timbers are far superior to Victorian houses.



It gets better and better....


It's all down to those new fangled polymerised timber trees they grow
now.... that where you get plastic wood from you know ;-)



Don't be silly John. Everyone knows its because all the timbers now go
to university and get a certificate of Political Correctness.

Franz Heymann wrote:


As clear as daylight. The reason for the reduced area of Thermomax is that
it has twice the efficiency as the flat plate. *Not* that it has "twice the
efficiency per square foot".


Its because he didn't go t uni. He's very sensitive about it.

He sort of graps the concept that a square foot of one is better than a
square foot of another, but detailed explanatins of teh correct words to
use just pass hum by.

He's a humpty dumpty. Words mean what HE wants them to mean.

IMM wrote:


Grow up!


or the noocooler bogglers will get you!!!

On Thu, 15 Jan 2004 01:36:40 +0000, The Natural Philosopher
wrote:

John Rumm wrote:

Dave Plowman wrote:

In article ,
IMM wrote:

Modern multi-braced roof trusses are cheap, and adequate, but won't
allow you to add a room in the attic like substantial victorian ones
might.



So? Modern timbers are far superior to Victorian houses.



It gets better and better....


It's all down to those new fangled polymerised timber trees they grow
now.... that where you get plastic wood from you know ;-)



Don't be silly John. Everyone knows its because all the timbers now go
to university and get a certificate of Political Correctness.

Has to be a non-snotty one though.

..andy

To email, substitute .nospam with .gl

"IMM" wrote in message
...

"Rod Hewitt" wrote in message
.. .
"IMM" wrote in
:

A car has no insulation, as they produce so much waste heat the
engines can provide enough even in the coldest conditions. Adding
insulation, bonded to the cars sheet metal around the cabin, would
improve matters. The drive motors and batteries produce heat, so this
must be available for use.

And also add to the cost and weight...

Insulation should not add that much weight. Cost? Mass production will
bring that down.

I doubt that any heat would be available from motors if they are fitted
into the wheel hubs.

If they are. Most electric cars have one motor.

There may be problems supplying enough electrical power for the
demisters,
seat heaters (oops, well I have a Saab), and other things (maybe needing
a
heater for the screen/headlamp wash and other currently
unnecessary/rarely
fitted devices).

Cars are full of unnecessary crap which add cost and weight affecting fuel
consumption, such as rev counters.

Please have a feeling for quantitative matters. Your car is capable of
producing more than 10^5 watts and you are mithering about an instrument
which uses at most 5 watts to produce data which is very valuable for
enabling you to use the engine effectively?

Why does anyone need to know how much
the engine is revving in a normal road car?

Beats me. I know when it is
revving, I hear and feel it.

I find it a very useful device for helping me to decide on when to change
gear. It is more quantitarive than just "having a feel for it"

If it is revved too much the management system
cuts it out. An electric window on the drivers side is unnecessary too,
as
are electric sunroofs, which are a British fascination. The French don't
want to know them.

At last we are in agreement about something

Why isn't the a/c an absorption system using waste engine heat, instead of
taking power off the crank, reducing mpg?

Franz

"IMM" wrote in message
...

"The Natural Philosopher" wrote in message
...
Franz Heymann wrote:

"The Natural Philosopher" wrote in message
...

Martin Brown wrote:



Solar power works reasonably at latitudes below about 45 degrees, but
it
is quite frankly a complete non-starter at latitudes 55N and above.
Unless you count biomass conversion in forests for indirect fuel
generation.



Agreed. Horses for courses.

However tide power is not impossible either. Not an easy one tho.

If only we could get fusion power working...


Fusion power is going to turn out to be a great deal filthier than
fission
power.



I don't think so. The fisson products would all be relatively short
lived isoptopes, and teh main product is helieum. Non radioactve helieum

Its only the vast amounts of radiation intereacting with the shielding
that would cause some radioactive compounds to be generated.


Fission power is the cleanest and least polluting energy source ever
produced on earth.



Yes, I tend to agree with you.


The number of deaths per kilowatt hour which occur in the extraction
and
processing of fossil fuels is a lot higher than the corresponding
number
for the extraction of uranium



I would not be surprised.


The pollution of the atmosphere by fossil fuel stations is vastly
worse
than
the pollution caused by nuclear power stations.

That is certainly true.

If all power stations were nuclear around the world the waste would pile
up
and be a huge problem in the future. Silly idea and should be forgotten.

It is obvious that you have never given a moments intelligent thought to
this question. You are just following the flock. The waste from a nuclear
power station is in fact a great deal easier to dispose of safely than the
waste from a fossil fuel plant. The trouble lies entirely in the fact that
the shepherds who persistently lead the sheep astray on this matter have not
even the faintest understanding of the issues involved in comparing methods
of disposing of waste from power stations.

Franz

"Franz Heymann" wrote in message
...

"IMM" wrote in message
...

"Rod Hewitt" wrote in message
.. .
"IMM" wrote in
:

A car has no insulation, as they produce so much waste heat the
engines can provide enough even in the coldest conditions. Adding
insulation, bonded to the cars sheet metal around the cabin, would
improve matters. The drive motors and batteries produce heat, so
this
must be available for use.

And also add to the cost and weight...

Insulation should not add that much weight. Cost? Mass production will
bring that down.

I doubt that any heat would be available from motors if they are
fitted
into the wheel hubs.

If they are. Most electric cars have one motor.

There may be problems supplying
enough electrical power for the
demisters, seat heaters (oops, well I
have a Saab), and other things (maybe needing
a heater for the screen/headlamp wash
and other currently unnecessary/rarely
fitted devices).

Cars are full of unnecessary crap which
add cost and weight affecting fuel
consumption, such as rev counters.

Please have a feeling for quantitative matters.
Your car is capable of producing more than
10^5 watts and you are mithering about an
instrument which uses at most 5 watts to
produce data which is very valuable for
enabling you to use the engine effectively?

Are you joking? How does a rev counter make the average driver use the
engine effectively/. Most ignore it. It is pretty well useless.

Why does anyone need to know how much
the engine is revving in a normal road car?

Beats me. I know when it is
revving, I hear and feel it.

I find it a very useful device for helping me
to decide on when to change
gear. It is more quantitarive than just
"having a feel for it"

99% of driver know when to change gear by the sounds and feel of the engine.
I know no one who looks at a rev counters. Also this is distracting, taking
the drivers eyes from the road.

If it is revved too much the management system
cuts it out. An electric window on the drivers side is unnecessary too,
as
are electric sunroofs, which are a British fascination. The French
don't
want to know them.

At last we are in agreement about something

Why isn't the a/c an absorption system using waste engine heat, instead
of
taking power off the crank, reducing mpg?

Franz




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"The Natural Philosopher" wrote in message
...
RichardS wrote:


Have removed the x-posting to u.r.g so as not to inflict them further
with
this ridiculous thread. Wish I'd never asked about bloody lichens and
mosses now.

Its no use talking to IMM since the diodes went all down his left hand
side.

LOL, such fun.


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"The Natural Philosopher" wrote in message
...
Franz Heymann wrote:

As clear as daylight. The reason for the reduced area of Thermomax is
that
it has twice the efficiency as the flat plate. *Not* that it has "twice
the
efficiency per square foot".


Its because he didn't go t uni.

I did. Thankfully not one of those snotty uni ones, full of half-breds.




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"Franz Heymann" wrote in message
...

The pollution of the atmosphere by fossil
fuel stations is vastly worse than
the pollution caused by nuclear power stations.

That is certainly true.

If all power stations were nuclear around
the world the waste would pile up
and be a huge problem in the future. Silly
idea and should be forgotten.

It is obvious that you have never given a
moments intelligent thought to
this question. You are just following the flock.

My God, he is the only with insight now.

The waste from a nuclear
power station is in fact a great deal easier
to dispose of safely than the
waste from a fossil fuel plant.

But is isn't!! It is dumped at the bottom of the ocean in casks that might
last 100 years, then they will slowly leak their toxic contents into the
ocean and into the food chain. This is a very sill idea. As people in the
20th century cursed the Victorian legacy of piled up dangerous slag heaps
and other filth, future generations will think the same of us.

The waste can be dumped down deep disused mines and then the seams concreted
up. In 1000 years time some one will probably tunnel into it. Of course
they will make a record, which will be lost. There are 4, 5 or 6 (no one
quite knows) underground store of TNT under Belgium fields. No one quite
knows where they are. These were the largest non-nuclear bombs ever made.
The British would tunnel under the German trenches, fill with TNT and
detonate, killing 10,000 men in one explosion from one bomb. The disused
bombs were not used because the British trenches had moved forwards over
them. One of these bombs went off by accident in 1955. Luckily no one was
killed. It is a matter of time before the others explode. Records of
where the bombs are? Some, but not all.

If every powerstatio in the world was nuclear, where would all the waste go?
Privately owned stations would cheaply dump the waste (illegal dumping of
chemicals in all countries is common), insead of down expensive deep mines
and sealing up with concrete. It is the human error aspect that is the
flaw. When it goes wrong the effects last for 100s of years after.

Also, cases of leukaemia are far greater around nuclear facilities. Just
co-incidence the nuclear people say. ********!!!

The trouble lies entirely in the fact that
the shepherds who persistently lead
the sheep astray on this matter have not
even the faintest understanding of the
issues involved in comparing methods
of disposing of waste from power stations.

They have a lot of common sense, that is clear. Dependency on fossil fuel
power can be vastly reduced by use of insulation, passive solar, superior
town planning eliminating cars, CHP, more efficient engines, etc, etc.



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IMM wrote:


99% of driver know when to change gear by the sounds and feel of the engine.
I know no one who looks at a rev counters. Also this is distracting, taking
the drivers eyes from the road.


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 :-)

In message , Franz Heymann
writes

"The Natural Philosopher" wrote in message
...
Franz Heymann wrote:

Fusion power is going to turn out to be a great deal filthier than
fission
power.

I don't think so. The fisson products would all be relatively short
lived isoptopes, and teh main product is helieum. Non radioactve helieum

Its only the vast amounts of radiation intereacting with the shielding
that would cause some radioactive compounds to be generated.

No. In the reactions which are presently considered, there will be a lot of
tritium around. Tritium is a gas and it has a long half life. It scares
the pants off me.

Tritium isn't all that bad. Its half life of about 12 years is short
compared to millenia for fission waste. Tritium is a beta emitter with
18keV electron decay and there is quite a market in tritiated plastics
for permanent glow in the dark (and still some requirement for H-bomb
initiators). Emergency lighting in some applications is based on it.

Fission power is the cleanest and least polluting energy source ever
produced on earth.

Yes, I tend to agree with you.

You have to get the whole life cycle right though. And they still
haven't an adequate solution for long term storage of high level waste.

Regards,
--
Martin Brown

In article ,
The Natural Philosopher wrote:
So? Modern timbers are far superior to Victorian houses.



It gets better and better....


It's all down to those new fangled polymerised timber trees they grow
now.... that where you get plastic wood from you know ;-)



Don't be silly John. Everyone knows its because all the timbers now go
to university and get a certificate of Political Correctness.

So they are full of saps, then?

--
*Welcome to **** Creek - sorry, we're out of paddles*

Dave Plowman London SW 12
RIP Acorn

In article ,
IMM wrote:
Its because he didn't go t uni.

I did. Thankfully not one of those snotty uni ones, full of half-breds.

But is so proud of it he's ashamed to name it...

--
*If a turtle doesn't have a shell, is he homeless or naked?

Dave Plowman London SW 12
RIP Acorn