wrote:
On 10 Jan, 21:16, The Natural Philosopher wrote:
wrote:
On 10 Jan, 12:20, "Mary Fisher" wrote:
wrote in message
...
On 9 Jan, 20:04, "Mary Fisher" wrote:
"Roger Mills" wrote in message
...
...
Even if he is, it's a very valid question - and one that seems to be
ignored by the government when thrusting these token green measures on
us.
Just as your average suburban domestic windmill will take more energy
to
manufacture it than it will ever generate in its lifetime.
Evidence?
Well you could try asking someone who's got one.
An owner doesn't usually know the energy cost of manufacture.
It is a difficult question to answer. For my own purposes, I assume
10% of the final cost to me, unless the item is manufactured in an
economy where energy and labour is cheap, where I assume 20%. So, a
1000ukp turbine will have to produce 200ukp of electricity, or 2000kWh
of electricity before it fails to energetically pay for its
manufacture. At 5 quid a year, not very likely.
The trouble is there
is nowhere near enough wind in most urban/suburban settings. It's a
bit old hat - even the most credulous innumerate greenies now accept
they don't work where there are trees and buildings.
Nobody is thrusting windmills on anyone.
I don't agree. The grants available, the extra points on your home
energy assessment, the example set by our betters (eg David Cameron),
domestic generation inducements from electricity suppliers etc. add up
to a very strong encouragement bordering on coercion.
Ive just been listening to the beeb.

germany will pay you about twice what they will sell you electricity at,
if you make it from windmills or solar panels. MASSIVE susbify, since
its totally unecomonic.

Contrast the speches today with respect to nuclear. "Has to pay for
itself, no government subsidies".

Level playing field my arse.


I sat open mouthed while watching the News at Ten tonight. With all
the spin on renewables we've endured over recent years, they finally
admitted what offshore wind costs - 85quid/MWh!!!

The figures they quoted we

Coal 30ukp/MWh
Gas 38ukp/MWh (and going up no doubt)
Nuclear 39ukp/MWh
Offshore Wind 85ukp/MWh

Some green energy companies will pay you based on what appears to be a
calculation (ie gross overestimate) of what your turbine might
produce. I note that Equipower will pay you 18p for every unit you
export vrom your solar panel! All this to get their hands on ROCs!


Interesting. I missed that.

It feels about right from my own calcs. I'd put the offshore wind costs
higher than that tho..a huge amount depends on how much the wind blows,
in the windmill case, and how much the nuclear reactors are run flat out
and therefore getting best use of capital,and fixed overheads, in the
nuclear case.

Both have virtually zero fuel costs but high fixed costs.

Another unknown factor is how long the stuff will last. The magnox stuff
has done what - 50 years? Will the windmills survive a hurricane or
three? I'd laugh myself silly if we see a aerial view of a lot of poles
standing in the water with the blades snapped off. Its all very well
feathering them IF the wind direction is constant.But would they stand
turbulence..at 120 mph? And what if the feathering or head rotation
mechanism fails..

Anyway, cost per KW is a function of the lifetime..you could argue - and
certainly British Energy shareholders seem to be, that teh vcapital cost
has depreciated to nothing, and its all profit..over running and
maintenance costs.

I don't know if you remember Clarkson on the supertanker 'This ship will
be run until the cost of maintaining it exceeds the cost of borrowing
enough to build another one: then it will be scrapped.'

I.e. if your maintenance costs of a nuclear power station exceed the
cost of borrowing enough to build a new one and decommission the old,
you do that. I suspect that the way British Energy will go now..get a
new one built alongside, and use that to fund the decommissioning of the
older sets. Then nick the turbines and boilers and generators and use
them in another set..if they are worth using.













T

On 10 Jan 2008 20:07:50 GMT someone who may be
(Andrew Gabriel) wrote this:-

We are certainly embarking on increased mercury pollution

No we aren't.

Indeed.

That this is a myth has been explained many times before, but for
those whose religion appears to be opposing anything green
http://www.bbc.co.uk/dna/actionnetwork/A22400182 provides some
information on the subject.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Thu, 10 Jan 2008 07:34:01 -0800 (PST) someone who may be "Man at
B&Q" wrote this:-

Where do you think the air warmed by a heater ends up?

You are assuming all heating is by convection.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 10 Jan 2008 15:01:22 GMT someone who may be Huge
wrote this:-

Combine that with the enthusiasm displayed by the likes of Hansen, Mary and
Hilary Benn (and other similar innumerates),

Excellent, rudeness and personal attacks in one posting. Do keep it
up.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

In article ,
David Hansen writes:
On 10 Jan 2008 20:07:50 GMT someone who may be
(Andrew Gabriel) wrote this:-

We are certainly embarking on increased mercury pollution

No we aren't.

Indeed.

That this is a myth has been explained many times before, but for
those whose religion appears to be opposing anything green
http://www.bbc.co.uk/dna/actionnetwork/A22400182 provides some
information on the subject.

The figures in there are a little out of date, and not for the EU.
We're better than that now with CFLs. Typical mercury contents
of new CFLs is now down to 3mg. Another 2.5mg is given off in the
electricty production, which is 5.5mg total. For an equivalent
filament lamp, 10mg is given off in the electricity production.

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would
have been written some time ago, and advances have allowed less
to be used since then.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Man at B&Q" wrote in message
news:bbd3d536-8d6d-4c8e-83c2-
....

Do you just have one tungsten bulb per room?

Mary

No of course not. But if I can't replace tungsten with low energy on a
one
for one basis, I'll have to install a lot more lighting points which -
quite apart from any cost and Part-P inplications - will spoil the look
of
many of my rooms.

So the look of your rooms is more iomportant than the future of the
environment and your power bills.

The environment will suffer far more from the dumping of end of life
CFLs and all they contain, than a bit of tungsten, glass and some
inert gas.

MBQ



It's the power used when bulbs are switched on which is the cost to the
environment.

Mary

wrote in message
...
On 10 Jan, 20:07, (Andrew Gabriel) wrote:
In article
,
writes:

We are certainly embarking on increased mercury pollution

No we aren't.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Thank you for that illuminating reply. I don't quite understand why
you bother though. Surely any possible humour in your persistently
childish responses has worn thin by now? Or is that really the best
you can do? In which case you have my sympathy.

Well you keep making statements without any back-up, is that the best you
can do?

Mary

"David Hansen" wrote in message
...
On 10 Jan 2008 15:01:22 GMT someone who may be Huge
wrote this:-

Combine that with the enthusiasm displayed by the likes of Hansen, Mary
and
Hilary Benn (and other similar innumerates),

Excellent, rudeness and personal attacks in one posting. Do keep it
up.

Oh, I didn't see that. People who write offensive posts end up in my kf so I
miss such gems :-)

Mary

"Mary Fisher" wrote in message
t...

"David Hansen" wrote in message
...
On 10 Jan 2008 15:01:22 GMT someone who may be Huge
wrote this:-

Combine that with the enthusiasm displayed by the likes of Hansen, Mary
and
Hilary Benn (and other similar innumerates),

Excellent, rudeness and personal attacks in one posting. Do keep it
up.

Oh, I didn't see that. People who write offensive posts end up in my kf so
I miss such gems :-)

Mary

Just had a thought though, I don't mind being associated with David Hansen,
nor being enthusiastic about important matters. Being positive is better
than being negative.

Mary

On Fri, 11 Jan 2008 12:06:17 UTC, "Mary Fisher"
wrote:

It's the power used when bulbs are switched on which is the cost to the
environment.

How naive.

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

On Thu, 10 Jan 2008 18:10:14 -0000, "Mark"
wrote:


"RobertL" wrote in message
...
On Jan 9, 8:10 pm, "Mark" wrote:
"Mark" wrote in message

...

I'll keep an eye open for higher wattage ones then. I don't
think I've ever seen ones higher than 20 / 22 watt.

Are the 27 watt ones the same size or larger?
--
David in Normandy

I've found these 60watt, equivant to 300 watt tungsten.

How much? king hell!

oops! Forgot the link. Here it is:-

http://www.lightbulbs-direct.com/var...l.asp?var=4119


They would be great, but they cost £47 EACH!!!!

Robert


You forgot the VAT so they cost £55.86 each.
A mere £50 each if you buy 10.

mark


You could get three 5' complete flourescent fittings with electronic
ballasts for that.

"Mary Fisher" wrote in message
t...

"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
Mary Fisher wrote:

"Roger Mills" wrote in message
...

Some rooms have low voltage halogen downlighters. What am I supposed
to replace *those* with?

There's no 'supposed' about it.


OK, so what *is* the situation? If these are to be banned, the 'powers
that be' have *hopefully* thought about a suitable replacement which
doesn't involve demolishing and re-building my house?

If the powers that be didn't enforce downlighting on you then they have no
responsibility to replace them.

I don't think that's a fair point though. I mean has anyone been forced to
use petrol
perhaps then we should ban it ;-)



I don't currently know what that is - although LED-based lights do look
reasonably promising.

I think so too. People dismiss them for their relatively (as yet) lopw
light emittance,

yes I have three in use but they aren't much good for lighting unless you're
about a foot away from them. I use them in the hallway but presently they
are just too dim to be practical anywhere else.

their colour (which I like)
Me too but I don;t wnat to watch TV by blue green or red light even if it
does cycle between the colours.

and for other imagined problems
I'm not sure the problems are imagined.

but I think they're the future.
OLEDs mighy be next.

I might not be here to see it but I shan't be here to see many other
exciting things.

I'm waiting for the time when each buld with have it's own sealed mini
nuclear reactor
in it and a guernetee where it's worth you're while taking the used bulb
back
to the supplier and you swop it out for a replacent for minmal cost.

If people got a couple of quid back for expended bulbs then that would
do far more to encourage true recycling. I remember the days when you'd get
money back on beer bottles. I imagined I could become a millionaire from
returning my empties but they stopped all that. :-(

"Man at B&Q" wrote in message
...
On Jan 10, 12:28 am, "OG" wrote:
"The Medway Handyman" wrote in
nder.co.uk... Mike
Scott wrote:
I'm curious. "Low energy" bulbs are very much in the news - but how
much extra energy is expended in their manufacture compared to a
standard incandescent? I assume it's more - so is there a real net
/overall/ saving over the bulb life? If so, how much?

Assuming that low energy bulbs are more efficient & give off less heat
for
a given amount of light, would you not have to replace that heat in
order
to maintain the same room temperature?

Yes but

No buts about it.

If your room needs heating, use a heater and put it where the heat needs
to
be. It's madly inefficient to put a heater about 10 inches from the
ceiling

}Why? Give us the science.

Because keeping the ceiling warm isn't a good idea unless you live above the
ceiling.
A lot of the heat generated in a bulb is in the filament and doesn't get
passed
on very far even though the glass gets quite hot, there's not usualy enough
air circulation
to take theheat from the bulb.



(which is in effect what you are doing with incandescent bulbs).

}Where do you think the air warmed by a heater ends up?


It doesn't really end up anywhere it gets dissipated and cools as it
circulates.



} the heat from the heater? Think of the bulb as providing
}the heat that would anyway dissipate through the ceiling to save the
}heater from having to do it.

}Same applies to TVs on standby.

But wasteful and ineffective as using a soldering irn to heat your home yes
it gets hot.
Similar thing with a kettle.

My father uses bulbs to warm things up but limits it to hospital cages for
budgies
where the bulb is under the cage and the heat rises which is fine for a
small cage
and a bird but a human would hardly notice the room warming up due to a 100w
incandescent bulb.

If it were such a good idea to have heat sources up high then radiators
would be mounted up high on the wall where they could be run much hotter
due to people being less likely to burn themselves if brushing against them.

It also seems to be why radiators are commonly placed under windows
so they can heat up the cold air around the windows making it rise,
after all there's little point in heating up hot air that is above your
head.

On 10 Jan 2008 15:01:22 GMT, Huge wrote:

On 2008-01-10, The Natural Philosopher wrote:

My own personal opinion is that the answers a-

Not very much
Its not hugely relevant
In many cases the disadvantages are NOT worth it.

Combine that with the enthusiasm displayed by the likes of Hansen, Mary and
Hilary Benn (and other similar innumerates), the fact that they don't actually
last as long as the manufacturers say and that some find the light and/or the
start-up time unacceptable, what other reasons do we need not to use them?

BTW, we went to India for a 2 week holiday a couple of months ago, and didn't
see a single filament bulb the whole time - all the lighting in hotels,
restaurants, etc., was CFLs. I have no idea what that means.

Lower A/C costs.

On Fri, 11 Jan 2008 00:21:38 +0000, Andrew Gabriel wrote:

In article ,
mick writes:

You sure about that? I oversimplified.

For a poor PF load the voltage and current are out of phase with each
other (how far depends on the PF PF=1 is in phase, PF=0 is 90deg out).
The generator is producing (and consuming fuel for) VA (real power).

It doesn't work like that. What's happening at the per mains cycle level
is that at one point in the cycle you are drawing more power than you
need, and at another point you are giving back the excess.

Correct, but you are giving it back later in the cycle, which effectively
shifts the voltage phase relative to the current phase. The difference in
phase angle is theta, and the PF is cos Theta.

The supply
infrastructure has to carry and be sized for this extra power you took
and then gave back (and weren't charged for) plus the power you actually
used, but all that happens is that someone else will use the power you
gave back and the generator doesn't need to produce it again for them.


Smoke & mirrors. We are looking at the load of a single CFL. Well, I am,
anyway. :-) True, lots of CFLs may well eventually "self correct" by all
adding their lousy PFs at the right time. lol!

However, the low power factor resulting from compact fluorescents
doesn't involve any significant phase shift.

Sorry, but it has to. The load is either inductive or capacitive so it
produces either a leading or lagging PF, which is very significant as a %
of the load when the PF is as bad as 0.5.

It results because the
power supply in the lamps only draws power in the peaks of the waveform.
This power draw only in the peak is stored in the lamp and used to
generate a continuous output. However, with supply losses being I^2R,
drawing twice the current for half the time still generates twice the
power loss in the supply infrastructure, although as Andy pointed out,
that's still less than the losses from an equivalent filament lamp. But
the power station in this case only has to generate the power for the
period of the cycle when the lamp draws it. Inertia of the generator
armatures smooths this out in practice.

Drawing energy only at the peak of the waveform creates harmonics on the
mains waveform, introducing distortion and adversely affecting the PF of
the load.

Eventually I suspect that all CFLs will contain some form of PF
correction in the form of filtering. As the number of them climbs the
power supply authorities will probably insist on it - or start charging
everyone by VA rather than W.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

"mick" wrote in message
. uk...
On Thu, 10 Jan 2008 22:54:21 +0000, Andy Wade wrote:

mick wrote:

[...] and the power station has to generate 60W to light your 30W CFL
(although you are only charged for 30W).


You sure about that? I oversimplified.

For a poor PF load the voltage and current are out of phase with each
other (how far depends on the PF PF=1 is in phase, PF=0 is 90deg out).
The generator is producing (and consuming fuel for) VA (real power).
However, domestic consumers pay by W (apparent power), not VA. So you see
30W of load at the meter and can measure the AC RMS current into the
lamp, but the V and A waveforms are out of phase so the actual V*A is
greater than the W value. (W=VA*PF so a 30W (apparent power) lamp with a
PF of 0.5 will require 30/0.5=60VA input to power it)

Agreed that the distribution losses into poor PF loads also escalate with
I^2R.

Also agree that the % difference on your bill will be insignificant. :-)


This is the same problem computer (& most switched mode) power suplpies
tend to have, in fact years ago we (the college) were told we'd have to pay
more
for our electricity due to this power factor because when you have 1000s of
computers on site it does add up.

"Jan Wysocki" wrote in message
k...
On 2008-01-10, Mary Fisher wrote:

"Roger Mills" wrote in message
...
[snip]

Some rooms have low voltage halogen downlighters. What am I supposed to
replace *those* with?

If they're MR16s, then there are 3 and 4W LEDS available (search for
Brilux/Luxeon/Cree MR16)

I've seen some 5W MR16 they recon they're equiv. to 20w halogen. £15

http://www.rapidonline.com/productin...du leno=78803


One thing that I haven't seen discussed is the health issue as a product of
brightness.
A friend has tried reading under LED lights and gets eye strain I believe
this is due to
the limited real brightness. Our eyes adapt in dim lights but don;t work as
efficiently
and our dept of field (what's in focus), and dim light does cause eye
strain.
So I'm a bit concerned about using dimmer lights to be green if my eye sight
suffers
in the long term.

I'd also like to find out for myself just how bright a light is rather than
rely on
the manufactures weighted & obscure specifications.
I'm thinking along the lines of using a digital camera as a light measuring
tool.

On Fri, 11 Jan 2008 13:18:19 -0000 Whisky-dave wrote :
A lot of the heat generated in a bulb is in the filament and doesn't
get passed on very far even though the glass gets quite hot, there's
not usualy enough air circulation to take theheat from the bulb.

If that were so, the bulb would just get hotter and hotter!

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On Fri, 11 Jan 2008 00:49:22 +0000, The Natural Philosopher wrote:

mick wrote:
On Thu, 10 Jan 2008 22:54:21 +0000, Andy Wade wrote:

mick wrote:

[...] and the power station has to generate 60W to light your 30W CFL
(although you are only charged for 30W).
That's a complete misunderstanding of the idea of power factor. The
[supply system] doesn't have to generate 60 W, nor burn fuel at a rate
equivalent to 60 watts worth of output. The (RMS) current drawn by
the lamp is the same as for 60 W resistive load, so resistive losses
in the cables are increased by a factor of four without power factor
correction. However the I^2*R losses due to current drawn by your
lighting load will pale into insignificance compared to that caused by
much heavier resistive loads (cookers, heaters, showers).



You sure about that? I oversimplified.

For a poor PF load the voltage and current are out of phase with each
other (how far depends on the PF PF=1 is in phase, PF=0 is 90deg out).
The generator is producing (and consuming fuel for) VA (real power).
However, domestic consumers pay by W (apparent power), not VA. So you
see 30W of load at the meter and can measure the AC RMS current into
the lamp, but the V and A waveforms are out of phase so the actual V*A
is greater than the W value. (W=VA*PF so a 30W (apparent power) lamp
with a PF of 0.5 will require 30/0.5=60VA input to power it)

Agreed that the distribution losses into poor PF loads also escalate
with I^2R.

Also agree that the % difference on your bill will be insignificant.
:-)


Substations have BANKS..ACRES of capacitors to correct for power factor,
so that the generators do NOT have to run widely differing VI phase
differences. Its not really clear what sort of PF a CFL is anyway..A
bridge rect and an electrolytic maybe? Or a half wave rect and an
electrolytic..I bet there is a lot of input ripple..its easy enough to
stabilise output ripple with an HF SMPS..anyway a bot of C across the
mains is good, as its in the reverse direction to all those motors and
things..there the current lags the voltage..with capacitors it tends to
lead a bit.

It doesn't work like that. You can't correct for distortion-induced power
factor problems by throwing caps at it. That usually results in worsening
the PF and setting up resonances in the system.

There is a good (but technical) paper on this he
http://users.ece.utexas.edu/~grady/POWERFAC.pdf

This is relevent too:
http://www.iaeel.org/IAEEL/NEWSL/199..._a_3_4_95.html

And this: (very interesting!)
http://sound.westhost.com/articles/incandescent.htm


--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

On Fri, 11 Jan 2008 10:12:34 +0000, Andrew Gabriel wrote:

snip

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would have
been written some time ago, and advances have allowed less to be used
since then.


Good point. Another is that manufacturers have no interest at all in
using high quantities of mercury as it isn't a cheap metal to extract or
manage. I'm pretty certain that they are attempting to keep the amount as
low as possible.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

On 11 Jan, 09:21, David Hansen
wrote:
On 10 Jan 2008 20:07:50 GMT someone who may be
(Andrew Gabriel) wrote this:-

We are certainly embarking on increased mercury pollution

No we aren't.

Indeed.

That this is a myth has been explained many times before, but for
those whose religion appears to be opposing anything greenhttp://www.bbc.co.uk/dna/actionnetwork/A22400182provides some
information on the subject.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

That's so funny. The article was article was written by an Action
Network user not the BBC"! Really, can't you tell? But wait, it gets
funnier...

Using the figures from the article you cite we have:
CFL - 6mg total manufacture + 2.4mg from power stations = total 8.4mg
GLS - all Hg from power stations
= total 10mg

Now for the really funny bit - the emissions from power stations is
for 100% coal, but we only use 30% coal in UK, giving revised figures
of:

CFL - 6.8mg Hg
GLS - 3.0mg of Hg !!!!!!!!!!

But there was no way you were going to spot that because you are a
credulous innumerate!

Thanks for the information, now there is no need for me to consider
the shocking inefficiencies of Chinese brown coal power plants etc.

T

On 11 Jan, 10:12, (Andrew Gabriel) wrote:
In article ,
David Hansen writes:

On 10 Jan 2008 20:07:50 GMT someone who may be
(Andrew Gabriel) wrote this:-

We are certainly embarking on increased mercury pollution

No we aren't.

Indeed.

That this is a myth has been explained many times before, but for
those whose religion appears to be opposing anything green
http://www.bbc.co.uk/dna/actionnetwo...400182provides some
information on the subject.

The figures in there are a little out of date, and not for the EU.
We're better than that now with CFLs. Typical mercury contents
of new CFLs is now down to 3mg. Another 2.5mg is given off in the
electricty production, which is 5.5mg total. For an equivalent
filament lamp, 10mg is given off in the electricity production.

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would
have been written some time ago, and advances have allowed less
to be used since then.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

You conveniently attribute all UK power generation to coal. Only 30%
is coal. Setting aside the energy and pollution of manufacture, and
the actual amount of mercury used in manufacture, even with your
optimistic figures, incandescent bulbs still win.

T

In article ,
mick writes:
On Fri, 11 Jan 2008 10:12:34 +0000, Andrew Gabriel wrote:

snip

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would have
been written some time ago, and advances have allowed less to be used
since then.

Good point. Another is that manufacturers have no interest at all in
using high quantities of mercury as it isn't a cheap metal to extract or
manage. I'm pretty certain that they are attempting to keep the amount as
low as possible.

It has to be made very pure for fluorescent lights too, or quality
goes to pot. I think it's 4 times distilled to get to the required
purety.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 11 Jan, 14:26, andrew@a17 (Andrew Gabriel) wrote:
In article ,
mick writes:

On Fri, 11 Jan 2008 10:12:34 +0000, Andrew Gabriel wrote:

snip

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would have
been written some time ago, and advances have allowed less to be used
since then.

Good point. Another is that manufacturers have no interest at all in
using high quantities of mercury as it isn't a cheap metal to extract or
manage. I'm pretty certain that they are attempting to keep the amount as
low as possible.

It has to be made very pure for fluorescent lights too, or quality
goes to pot. I think it's 4 times distilled to get to the required
purety.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

So where do they dump all the contaminated gunge left at the end?

T

In article ,
mick writes:
On Fri, 11 Jan 2008 00:21:38 +0000, Andrew Gabriel wrote:

In article ,
mick writes:

You sure about that? I oversimplified.

For a poor PF load the voltage and current are out of phase with each
other (how far depends on the PF PF=1 is in phase, PF=0 is 90deg out).
The generator is producing (and consuming fuel for) VA (real power).

It doesn't work like that. What's happening at the per mains cycle level
is that at one point in the cycle you are drawing more power than you
need, and at another point you are giving back the excess.

Correct, but you are giving it back later in the cycle, which effectively
shifts the voltage phase relative to the current phase. The difference in
phase angle is theta, and the PF is cos Theta.

Yes indeed (although I'd prefer to say you shift the current phase
relative to the voltage phase, as you only control the current).

The supply
infrastructure has to carry and be sized for this extra power you took
and then gave back (and weren't charged for) plus the power you actually
used, but all that happens is that someone else will use the power you
gave back and the generator doesn't need to produce it again for them.

Smoke & mirrors.

Well, it explains the issue you brought up of why the generator
only needs to supply the power used, and not the VA.

We are looking at the load of a single CFL. Well, I am, anyway. :-)

OK, it can be different when you only have one load (depending
if the supply is one you can feed power back into). A UPS or
inverter will not be able to take back the power you didn't use
for reuse (and might actually waste further power trying to
absob it), and will need to be sized for the VA. An older simpler
rotary generator may be able to take it back and store it in the
rotor inertia so it doesn't need quite as much fuel to maintain
the speed.

True, lots of CFLs may well eventually "self correct" by all
adding their lousy PFs at the right time. lol!

It's different loads with different PF's and shifts which benefit
from this, although they don't have to be net balanced.

However, the low power factor resulting from compact fluorescents
doesn't involve any significant phase shift.

Sorry, but it has to. The load is either inductive or capacitive so it
produces either a leading or lagging PF, which is very significant as a %
of the load when the PF is as bad as 0.5.

This is wrong. A load which is inductive or capacitive has a phase
shift and a resulting PF 1, but this is not the only way to get
a PF 1.

It results because the
power supply in the lamps only draws power in the peaks of the waveform.
This power draw only in the peak is stored in the lamp and used to
generate a continuous output. However, with supply losses being I^2R,
drawing twice the current for half the time still generates twice the
power loss in the supply infrastructure, although as Andy pointed out,
that's still less than the losses from an equivalent filament lamp. But
the power station in this case only has to generate the power for the
period of the cycle when the lamp draws it. Inertia of the generator
armatures smooths this out in practice.

Drawing energy only at the peak of the waveform creates harmonics on the
mains waveform, introducing distortion and adversely affecting the PF of
the load.

Exactly -- you have no phase shift, but you have another way to get
PF 1. (Well, you could do a fourier transform of the peak pulse
current waveform and work out all the harmonic compontents, and
try to argue that all except the fundamental are shifted, but as
they're not at the mains frequency, that's inevitable. Given the
fundamental is not shifted and the other harmonics will all be
odd ones and symmetrical, I would argue there's no phase shift.)

Eventually I suspect that all CFLs will contain some form of PF
correction in the form of filtering. As the number of them climbs the
power supply authorities will probably insist on it - or start charging
everyone by VA rather than W.

EU has rules for switched mode power supplies (which is what CFLs
use). Those above a certain power rating must be power factor
corrected, but I think all CFL's fall below this limit. It's quite easy
to make them power factor corrected just by removing the smoothing
capacitor, but you get 100Hz flicker, and a drop in the efficiency
of the gas discharge due to stopping and starting it at this speed.
There are more complex ways to correct the PF of a SMPSU, but not
very consistant with a cheap throwaway consumable.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 11 Jan 2008 14:26:07 UTC, andrew@a17 (Andrew Gabriel) wrote:

In article ,
mick writes:
On Fri, 11 Jan 2008 10:12:34 +0000, Andrew Gabriel wrote:

snip

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would have
been written some time ago, and advances have allowed less to be used
since then.

Good point. Another is that manufacturers have no interest at all in
using high quantities of mercury as it isn't a cheap metal to extract or
manage. I'm pretty certain that they are attempting to keep the amount as
low as possible.

It has to be made very pure for fluorescent lights too, or quality
goes to pot. I think it's 4 times distilled to get to the required
purety.

Needing more energy...

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

In article ,
"Bob Eager" writes:
On Fri, 11 Jan 2008 14:26:07 UTC, andrew@a17 (Andrew Gabriel) wrote:

It has to be made very pure for fluorescent lights too, or quality
goes to pot. I think it's 4 times distilled to get to the required
purety.

Needing more energy...

Boiling 3mg of mercury, hum.
Actually, the lamp does that every time you switch it on.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"whisky-dave" wrote in message
news:fm7q7i$995$1@qmul...

"Mary Fisher" wrote in message
t...

"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
Mary Fisher wrote:

"Roger Mills" wrote in message
...

Some rooms have low voltage halogen downlighters. What am I supposed
to replace *those* with?

There's no 'supposed' about it.


OK, so what *is* the situation? If these are to be banned, the 'powers
that be' have *hopefully* thought about a suitable replacement which
doesn't involve demolishing and re-building my house?

If the powers that be didn't enforce downlighting on you then they have
no responsibility to replace them.

I don't think that's a fair point though. I mean has anyone been forced to
use petrol
perhaps then we should ban it ;-)

Leaded petrol WAS banned.

Today's fuel; for cars - even the cars themselves - one day will be banned
ifonly by people, because there are better alternatives.



I don't currently know what that is - although LED-based lights do look
reasonably promising.

I think so too. People dismiss them for their relatively (as yet) lopw
light emittance,

yes I have three in use but they aren't much good for lighting unless
you're
about a foot away from them. I use them in the hallway but presently they
are just too dim to be practical anywhere else.

their colour (which I like)
Me too but I don;t wnat to watch TV by blue green or red light even if it
does cycle between the colours.

You don't watch tv in the hall though - well, most people don't in my
experience. We don't watch it at all.

and for other imagined problems
I'm not sure the problems are imagined.

but I think they're the future.
OLEDs mighy be next.

I might not be here to see it but I shan't be here to see many other
exciting things.

I'm waiting for the time when each buld with have it's own sealed mini
nuclear reactor
in it and a guernetee where it's worth you're while taking the used bulb
back
to the supplier and you swop it out for a replacent for minmal cost.

I wish I undertstood all that ...

If people got a couple of quid back for expended bulbs then that would
do far more to encourage true recycling. I remember the days when you'd
get
money back on beer bottles. I imagined I could become a millionaire from
returning my empties but they stopped all that. :-(

Ah, the power of the pocket. Well, if money is important to you I suggest
you switch to low power bulbs and efficient gadgets.

Mary

On Fri, 11 Jan 2008 13:18:19 -0000 someone who may be "whisky-dave"
wrote this:-

Because keeping the ceiling warm isn't a good idea unless you live above the
ceiling.

Indeed. That is why heat recovery luminaires (in large air-
conditioned buildings) involve sucking hot air from the ceiling and
making use of it elsewhere. If the hot air was of use at ceiling
level the expense of doing this would not be worthwhile.




--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

wrote in message
...

....

That's so funny. The article was article was written by an Action
Network user not the BBC"! Really, can't you tell? But wait, it gets
funnier...


Ah - 'I heard it on the BBC so it must be true' ... perhaps you're too young
to remember that refrain :-)

Mary

"Bob Eager" wrote in message
...
On Fri, 11 Jan 2008 12:06:17 UTC, "Mary Fisher"
wrote:

It's the power used when bulbs are switched on which is the cost to the
environment.

How naive.

Most things appear so when taken out of context.

As does 'how naive' (sic)

Mary

"whisky-dave" wrote in message
news:fm7rco$9li$1@qmul...

"Jan Wysocki" wrote in message
k...
On 2008-01-10, Mary Fisher wrote:

"Roger Mills" wrote in message
...
[snip]

Some rooms have low voltage halogen downlighters. What am I supposed to
replace *those* with?

If they're MR16s, then there are 3 and 4W LEDS available (search for
Brilux/Luxeon/Cree MR16)

I've seen some 5W MR16 they recon they're equiv. to 20w halogen. £15

http://www.rapidonline.com/productin...du leno=78803


One thing that I haven't seen discussed is the health issue as a product
of brightness.
A friend has tried reading under LED lights and gets eye strain I believe
this is due to
the limited real brightness. Our eyes adapt in dim lights but don;t work
as efficiently
and our dept of field (what's in focus), and dim light does cause eye
strain.
So I'm a bit concerned about using dimmer lights to be green if my eye
sight suffers
in the long term.

I'd also like to find out for myself just how bright a light is rather
than rely on
the manufactures weighted & obscure specifications.
I'm thinking along the lines of using a digital camera as a light
measuring tool.

As someone else, perhaps not here, the matter of perceived brightness is
subjective.

Mary

"Tony Bryer" wrote in message
...
On Fri, 11 Jan 2008 13:18:19 -0000 Whisky-dave wrote :
A lot of the heat generated in a bulb is in the filament and doesn't
get passed on very far even though the glass gets quite hot, there's
not usualy enough air circulation to take theheat from the bulb.

If that were so, the bulb would just get hotter and hotter!

It does in an enclosed space, which is why that's not advocated.

Mary

On 11 Jan, 17:16, "Mary Fisher" wrote:
wrote in message

...

...



That's so funny. The article was article was written by an Action
Network user not the BBC"! Really, can't you tell? But wait, it gets
funnier...

Ah - 'I heard it on the BBC so it must be true' ... perhaps you're too young
to remember that refrain :-)

Mary

I not with interest you completely ignore the figures I gave. Based on
the authoritive article written by someone not from the BBC, normal
incandescent lamps produce less than half the mercury pollution of
CFLs.

T

On 11 Jan, 12:07, "Mary Fisher" wrote:
wrote in message

...



On 10 Jan, 20:07, (Andrew Gabriel) wrote:
In article
,
writes:

We are certainly embarking on increased mercury pollution

No we aren't.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Thank you for that illuminating reply. I don't quite understand why
you bother though. Surely any possible humour in your persistently
childish responses has worn thin by now? Or is that really the best
you can do? In which case you have my sympathy.

Well you keep making statements without any back-up, is that the best you
can do?

Mary

Fortunately for me I was backed up, all be it unwittingly, by someone
else.

T

On 09 Jan 2008 22:49:05 GMT, (Andrew
Gabriel) wrote:

In article ,
Derek Geldard writes:

The one's I got were "daylight" and probably made for "Growing
vegetation in an environment sealed from daylight" IYSWIM.

They would be completely wrong for that.
Actually, the high colour temperature "daylight" tubes are
completely wrong for almost every application you can think
of.

Viewing X-ray films.

Quilting.

Setting the grey scale on colour monitors.

DG

whisky-dave wrote:


If people got a couple of quid back for expended bulbs then that would
do far more to encourage true recycling. I remember the days when
you'd get money back on beer bottles. I imagined I could become a
millionaire from returning my empties but they stopped all that. :-(

As kids we used to supplement our pocket money by returning 'deposit'
bottles. Very effective - we would scour the neighbourhood to ensure no
bottle escaped. Don't know why they don't do it now.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

mick wrote:
On Fri, 11 Jan 2008 10:12:34 +0000, Andrew Gabriel wrote:

snip

IIRC, the EU max permitted mercury in a CFL is 5mg, but that would
have been written some time ago, and advances have allowed less to
be used since then.


Good point. Another is that manufacturers have no interest at all in
using high quantities of mercury as it isn't a cheap metal to extract
or manage. I'm pretty certain that they are attempting to keep the
amount as low as possible.

Thats a good point too. Market forces - nobody is going to put more than
they absolutely have to into a bulb because of cost.

A while ago the tree huggers were all wittering on about excessive
fertiliser use. Like the hole in the ozone layer they seem to have
forgotton that now because they have global warming to witter on about.

No farmer would use more fertiliser than he had too because of the cost.
They are very sharp people IME.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

"The Medway Handyman" wrote in message
.uk...
whisky-dave wrote:


If people got a couple of quid back for expended bulbs then that would
do far more to encourage true recycling. I remember the days when
you'd get money back on beer bottles. I imagined I could become a
millionaire from returning my empties but they stopped all that. :-(

As kids we used to supplement our pocket money by returning 'deposit'
bottles. Very effective - we would scour the neighbourhood to ensure no
bottle escaped. Don't know why they don't do it now.


I can vaguely remember getting 3d for each empty Corona bottle. Was that
right?

mark

On Fri, 11 Jan 2008 22:45:14 -0000, "Mark"
wrote:


I can vaguely remember getting 3d for each empty Corona bottle. Was that
right?


Can't see it would be worth flying it back to Mexico to be re-filled.

But then these 'ere Green****ers will skin turds for ha'pennies.

Hello Mary,

We know you're there.

DG