The mechanical aspects are bad enough. They are all too large.

Don't be so sure these days. I've managed to buy golf ball bulbs only
slightly larger than incandescent ones. They are half the size of an
incandescent GLS.

My main issue is with the appalling quality of the light produced.

Many bulbs are fine these days. The main problem is that it is a bit hit and
miss when you buy a bulb. Some are excellent. Some are dire. Some sort of
labelling about light quality could seriously help here. Perhaps as well as
the A-G scale for energy efficiency, they could institute an A-G scale for
spectrum quality.

Christian.

Domestic fuel consumption is actually far greater than all the electricity
consumption of fuel put together, and transport exceeds them both.

Perhaps that is because of lack of insulation. All the houses I have run
have had electricity consumption and gas consumption at a similar cost. I
don't recognise the heating being considerably more than electricity.

Christian.

Christian McArdle wrote:
Domestic fuel consumption is actually far greater than all the electricity
consumption of fuel put together, and transport exceeds them both.

Perhaps that is because of lack of insulation. All the houses I have run
have had electricity consumption and gas consumption at a similar cost. I
don't recognise the heating being considerably more than electricity.

Christian.


It may well be: you are certainly the exception, not the rule.

I think this is true of modern urban terraced/flat or semi-d type
houses..but a larger detached house has a lot more exposed wall per unit
floor area. whereas for a given floor area lighting requirements remain
more or less constant.

You might say that that is a recipe to insist that all housing should be
built in terraced or tower block form...;-)

...OTOH urban STREET LIGHTING is a HUGE waste of power - a fact that some
councils have twigged to.

The Natural Philosopher wrote:

[...]

Order on line, and save 3 gallons. Thats about 463 MJ of energy.

If that had been burnt in a power station it would probably be around
200 Megajoules of electrical output.

There are 8760 hours in a year. 3 Mega seconds. So thats about 66W

31.5 Ms in a year, not 3, so about 6 watts equivalent.

So. *That one trip to London and back equates to a

6 W thingy

on 24x7 ALL YEAR*.

--
Andy

The Natural Philosopher wrote:
Pete C wrote:
On Thu, 24 Aug 2006 17:36:42 +0100, Andy Hall
wrote:

I'd have to factor in all of my various servers and networking equipment......

There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).

Wel I have just replaced my 17" monitor that was about 50W, with a 19"
LCD which on standby, is about 3W I think.

But I bet there's a wall-wart associated with it that consumes more
than 3W on standby :-(

So. *That one trip to London and back equates to a

6 W thingy

on 24x7 ALL YEAR*.

So, say an average mileage of 12000 miles is equivalent to having 600W of
lighting on all year. Some people use over 500W in a single room with
halogen downlighters. If you have them in every room, you could well emit
more CO2 from your lighting alone in one year than driving for 12,000 miles.

Even a more typical setup of 500W of halogen in the kitchen and an average
of 150W in other rooms (some 100W incandescent and some halogen) could
easily eat up a good 3-6000 miles worth of CO2 annually.

Christian.

Andy Wade wrote:
The Natural Philosopher wrote:

[...]

Order on line, and save 3 gallons. Thats about 463 MJ of energy.

If that had been burnt in a power station it would probably be around
200 Megajoules of electrical output.

There are 8760 hours in a year. 3 Mega seconds. So thats about 66W

31.5 Ms in a year, not 3, so about 6 watts equivalent.

So. *That one trip to London and back equates to a

6 W thingy

on 24x7 ALL YEAR*.

Apologies. Miscounted the 0's.

Still at an average duty cycle of say 10%..Which is probably what
lightbulbs actually get...

Domestic fuel consumption is actually far greater than all the electricity
consumption of fuel put together, and transport exceeds them both.

Actually no. The following article suggests that on a global scale, lighting
alone emits the same CO2 as two thirds of cars. It is well worth tackling.

Christian.

Light's Labour's Lost -- Policies for Energy-efficient Lighting, 560 pages,
ISBN 92-64-10951-X, paper ?100, PDF ?80 (2006)
Type: Studies
Subject: Climate Change ; CO2 Emissions ; Electricity ; Energy Efficiency ;
Energy Policy ; Energy Projections ; G8
When William Shakepeare wrote Love's Labour's Lost he would have used light
from tallow candles at a cost (today) of £12,000 per million-lumen hours.
The same amount of light from electric lamps now costs only £2! But today's
low-cost illumination still has a dark side. Globally, lighting consumes
more electricity than is produced by either hydro or nuclear power and
results in CO2 emissions equivalent to two thirds of the world's cars.

A standard incandescent lamp may be much more efficient than a tallow
candle, but it is far less efficient than a high-pressure sodium lamp. Were
inefficient light sources to be replaced by the equivalent efficient ones,
global lighting energy demand would be up to 40% less at a lower overall
cost. Larger savings still could be realised through the intelligent use of
controls, lighting levels and daylight.

But achieving efficient lighting is not just a question of technology; it
requires policies to transform current practice. This book documents the
broad range of policy measures to stimulate efficient lighting that have
already been implemented around the world and suggests new ways these could
be strengthened to prevent light's labour's from being lost.

Martin Bonner wrote:
The Natural Philosopher wrote:
Pete C wrote:
On Thu, 24 Aug 2006 17:36:42 +0100, Andy Hall
wrote:

I'd have to factor in all of my various servers and networking equipment......
There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).
Wel I have just replaced my 17" monitor that was about 50W, with a 19"
LCD which on standby, is about 3W I think.

But I bet there's a wall-wart associated with it that consumes more
than 3W on standby :-(

Actually NOT.

In fact it is a watt on standby.

http://www.samsung.com/uk/products/m...Specifications

less than 38W on full blast.

And not that expensive either.

Christian McArdle wrote:
So. *That one trip to London and back equates to a
6 W thingy

on 24x7 ALL YEAR*.

So, say an average mileage of 12000 miles is equivalent to having 600W of
lighting on all year. Some people use over 500W in a single room with
halogen downlighters. If you have them in every room, you could well emit
more CO2 from your lighting alone in one year than driving for 12,000 miles.

Even a more typical setup of 500W of halogen in the kitchen and an average
of 150W in other rooms (some 100W incandescent and some halogen) could
easily eat up a good 3-6000 miles worth of CO2 annually.

Christian.


Assuming you had the lot on all the time.
Which of course you do not.

Assumong that the ancillary energy requirements of your car - the energy
into new tyres, brake pads and the like - is zero. Which of course they
are not.

My biggests room - the kitchen . 35 sq meters - has precisely 9 50W
spots in it. And three 40W candles. All on three separate dimmed
circuits. 570W in total.

I think I would have noticed if the electricity consumption had
trebled...the fact is they get at best about 4 hours of usage per day -
more in winter, less in summer.

Let's say I could knock those down to 120W - saving on average 350W *
365 *4 or 500 KWh. If I could get dimmable CFL spots I certainly would
consider it..but what am I saving..£50 a year. ONE tankful of diesel. In
mioney terms.

Or in carbon terms about 100 litres of fuel...

Great. When I used to work and commute, that would have lasted me
precisely three days in the car..

Christian McArdle wrote:

Maybe it is sometimes, but I think its also used fairly enough. Just
how much government control of your life do you want? Where do we draw
the line?

You draw the line where behaviour adversely affects others to an
unreasonable degree.

but that only shows the problem - that there is a very wide spectrum of
opinion on where that point lies.


The constructive path would be to look at why people arent buying
many cfls and address the issues with them. And theres nothing difficult
about doing so.

My belief is that the main reason is because of a combination of unit
purchase price disparity and the stupidity of the average purchaser. I don't
believe that people specifically and intentionally buying vanity bulbs is
the main problem. I think that if vanity bulbs were seriously increased in
price, then the majority, who couldn't tell the colour spectrum of a sodium
light from an incandescent, would buy CFLs and those who want to continue
with halogens can pay enough extra to offset the carbon.

I expect it would work that way. Its a lot of extra costs running the
taxation system though, and would only alienate the end consumers. I'd
much rather see the poor light quality of some cfls issue addressed,
which is their prime problem. And the misleading power equivalance
figures. And tip to base dimension labelling. This approach would
satisfy what consumers want and avoid the extra costs of taxation.

Once again _not_ nannying forces one to look at actually solving the
problem, which is surely a far better option.


And in other areas like part p... I dont even need to comment.

Yes. Part P fails on many counts. It was ill thought out and didn't pass the
test of adversely affecting others. Pure protectionism from vested
interests.

Yes. But... Part P was believed at the time by the govt to be a measure
that would prevent adverse effects on people. My point was that
a) whenever one body regulates others, it will make mistakes.
b) in practice its level of comprehension may be so poor that it is
simply disruptive and counterproductive.

This is just one more argument against governments fiddling with the
minutiae of peoples lives, because they arent really competent to do
so.


NT

And the misleading power equivalance figures.

I'm not sure they are that misleading. It is just that they take a few
minutes to warm up.

Christian.

The Natural Philosopher wrote:
Pete C wrote:
On Thu, 24 Aug 2006 17:36:42 +0100, Andy Hall
wrote:

I'd have to factor in all of my various servers and networking equipment......

There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).

Wel I have just replaced my 17" monitor that was about 50W, with a 19"
LCD which on standby, is about 3W I think. About 30W illuminated..

Note that replacing _working_ CRT monitors with LCDs is
counterproductive energywise. Although it reduces electricity use, the
money cost and energy cost of buying the monitor are never paid back by
these reductions. So those of us with an army of CRTs should ideally
keep them.


The PCs - well..it costs money to go for ultra small chips that can
still switch fast enough at lower power. The problem is inherent to
Microsnot..it needs giga flops to even put the welcome screen up, let
alone the bloatware it normally runs.

yes, pc psus are so inefficient because its slightly cheaper that way.
Laptops underclock CPUs to reduce energy use, but in desktops consumers
just want faster, they dont ask about energy figures when buying.
Labelling with typical anual energy use & cost might swing a few sales
to more efficient machines.


NT

Fash wrote:
wrote:
Fash wrote:

So dont start there at all, its the worst of all options. Halogens are
also the highest fire risk of all lighting types, and have other issues
too.

The point is that the mains ones are used in exactly the same way as
low voltage halogens so if you want halogens use low voltage not mains.

I understand, but I dont think that makes it logical to recommend any
halogens.


The point of using halogens is that they are much more directional than
either incandescent or fluorescent (of all varieties) this makes them
very good for task lighting which is what you need in a kitchen

no, if you want task lighting, put the lighting where the task is and
use some flavour of fluorescent. Halogen is not a good choice.


re LEDs, theyre still gimmick lighting at this time. Maybe one day, but
certainly not today, not for normal household uses.

The kind of lighting the OP is talking about is the first place that
LEDs will break into the market.

I cant help but notice that when people talk about LED lighting its
always 'will'. 'Will' means 'doesnt.' LEDs simply do not compare well
to anything for normal domestic lighting. They are niche products only,
the rest is just hype.


Take a look at Luxeons latest K2
devices and efficiency is on a par with CFL the issue is just cost.

But that is a self contradiction. High production cost equals a lot of
energy input in production, making the thing not so energy efficient
after all. High purchase price means again it does not compete cost
wise. LEDs are simply not on a par with cfls, and never have been.
Flourescent technology has been the winner for general lighting for
many decades, and still is.


For
broad diffuse lighting LEDs have much further to go as CFLs are pretty
good at this and the emission profile (virtually isotropic from a CFL)
is similar to what we're used to from incandescent. LEDs on the other
hand need lots of optics to create a beam profile that's isotropic
since output is usually lambertian or if a lens is used fairly focused.

Its just as possible that LEDs will never get there. They never have so
far, and LED technology has been around for decades. But what really
counts is theyre not there today - and never have been.

We can specualte about the future gains in LED technology, but other
technologies also advance over time, and have always won over LEDs to
date. LEDs have their place, but it isnt for general lighting. To
illuminate the picture, just look at a graph of efficacy versus year
for LEDs and flourescent from the 1930s to today. LED is way behind.


NT

Pete C writes:

There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).

Because laptops are designed to do this otherwise battery life would
be really bad.

PCs are a collection of interchangeable components made by
manufacturers who simply want to make money.

To make a low power machine you can't use these intgerchangeable
components and you shouldn't use anything x86, which is an
environmental and technical disaster area. A mac mini uses 20-30W I
believe.

You can compare Apples and Apples when you see that Apple stopped
mentioning laptop battery life since the switch to Intel.

Jon

Haitz law says that LED brightness doubles ~every 2 years and in fact
it's getting quicker than that. LED products are already in the market
place in niche areas such as architectural lighting and signalling.
Also they are getting pushed into larger and larger LCDs as a result of
regulation. In the automotive area the drive to remove mercury is now
quite serious and the EU and other regulatory bodies are able to skew
normal market economics resulting in earlier tipping points. One of the
big reasons LEDs don't compete is that the volumes are too small AND
the companies producing them are still working on high margins. This is
not sustainable as Taiwan and China (who generally care less about
intellectual property) move into the market prices will drop
significantly. At the moment ~1/2 the cost of a white LED is license
fees for other peoples patents. This means you're total energy market
is not as accurate as you might think although clearly lawyers do
generate lots of hot air.

The other thing you're wrong or at least over egging is improvements in
fluorescent technology. There has been very little improvement in CCFL
over the last 20 years and newer developments like HCFL and EEFL are
not more efficient they just offer control benefits around things like
dimming and flashing which are not important for general lighting.

Cheers

Fash

On 2006-08-25 10:43:38 +0100, The Natural Philosopher said:

Christian McArdle wrote:
Domestic fuel consumption is actually far greater than all the
electricity consumption of fuel put together, and transport exceeds
them both.

Perhaps that is because of lack of insulation. All the houses I have
run have had electricity consumption and gas consumption at a similar
cost. I don't recognise the heating being considerably more than
electricity.

Christian.


It may well be: you are certainly the exception, not the rule.

I think this is true of modern urban terraced/flat or semi-d type
houses..but a larger detached house has a lot more exposed wall per
unit floor area. whereas for a given floor area lighting requirements
remain more or less constant.

You might say that that is a recipe to insist that all housing should
be built in terraced or tower block form...;-)

..OTOH urban STREET LIGHTING is a HUGE waste of power - a fact that
some councils have twigged to.

Absolutely. Anything that could be done to dispense with those
hideous sodium and mercury vapour lights would be superb.

Even a more typical setup of 500W of halogen in the kitchen and an
average of 150W in other rooms (some 100W incandescent and some halogen)
could easily eat up a good 3-6000 miles worth of CO2 annually.

Assuming you had the lot on all the time.
Which of course you do not.

Er. If you had the whole lot on all the time, it would be far worse.

The 3000 mile figure was using the 10% duty cycle that Nat Phil suggested.
Certainly not 100%.

Assumong that the ancillary energy requirements of your car - the energy
into new tyres, brake pads and the like - is zero. Which of course they
are not.

Well, the house has considerable energy input into cement, plaster, paint,
even wood. What is your point?

Or in carbon terms about 100 litres of fuel...

Great. When I used to work and commute, that would have lasted me
precisely three days in the car..

Perhaps you were commuting more than average? Perhaps your car was obscenely
wasteful. My Peugeot 107 would go 450 miles on 33 litres of fuel. Were you
commuting 225 miles a day? Were you driving a wasteful car? Could at least
some commuting be done using telecommunications?

Christian.

Were you commuting 225 miles a day?

Whoops. I mean 150 miles a day.

Christian.

On 2006-08-25 13:02:59 +0100, Jonathan Schneider
said:

Pete C writes:

There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).

Because laptops are designed to do this otherwise battery life would
be really bad.

PCs are a collection of interchangeable components made by
manufacturers who simply want to make money.

To make a low power machine you can't use these intgerchangeable
components and you shouldn't use anything x86, which is an
environmental and technical disaster area. A mac mini uses 20-30W I
believe.

You can compare Apples and Apples when you see that Apple stopped
mentioning laptop battery life since the switch to Intel.

Jon

It actually isn't bad - MacBook Pro seems to be quite a bit better than
nearest equivalent PC hardware. Part of it seems to be that MacOS X
does a much better power management job than the Redmond Rubbish.

"Andy Hall" wrote in message
...
On 2006-08-25 13:02:59 +0100, Jonathan Schneider
said:

You can compare Apples and Apples when you see that Apple stopped
mentioning laptop battery life since the switch to Intel.

Jon

It actually isn't bad - MacBook Pro seems to be quite a bit better than
nearest equivalent PC hardware. Part of it seems to be that MacOS X
does a much better power management job than the Redmond Rubbish.



Apple switched to Intel because Intel processor deliver a lot more
processing power per watt than the Power PC processors.
This was true of the Centrino and is even better for the Core processors.

Apple knew that if it didn't switch it was going to have real problems
competing.

As for OSX being better than windows.. that is personal choice and depends
more on which applications you want to run.

On 2006-08-25 16:20:36 +0100, "dennis@home"
said:


"Andy Hall" wrote in message ...
On 2006-08-25 13:02:59 +0100, Jonathan Schneider
said:

You can compare Apples and Apples when you see that Apple stopped
mentioning laptop battery life since the switch to Intel.

Jon

It actually isn't bad - MacBook Pro seems to be quite a bit better than
nearest equivalent PC hardware. Part of it seems to be that MacOS X
does a much better power management job than the Redmond Rubbish.



Apple switched to Intel because Intel processor deliver a lot more
processing power per watt than the Power PC processors.
This was true of the Centrino and is even better for the Core processors.

Apple knew that if it didn't switch it was going to have real problems
competing.

As for OSX being better than windows.. that is personal choice and
depends more on which applications you want to run.

It's Unix. Of course it's better than Windows.

I''ve been able to sleep and restart the Mac for the last two months.
It was last rebooted in early July. In that time, it has been on and
off literally hundreds of fixed and wireless networks, had applications
exited and restarted or just left dormant. It has behaved faultlessly.

If I try to do anything close to that with Windows, I'm lucky if it
lasts a day between reboots and a ridiculously long start up time
because of all the crap that gets loaded.

I do still have a very small number of legacy Windows applications that
don't have equivalent Mac versions. I can run these in Parallels
with XP or dual boot with Bootcamp.

Christian McArdle wrote:
Domestic fuel consumption is actually far greater than all the electricity
consumption of fuel put together, and transport exceeds them both.

Actually no. The following article suggests that on a global scale, lighting
alone emits the same CO2 as two thirds of cars. It is well worth tackling.


yes, but the average town has about ten times as much street lighting
that is on ALL NIGHT as the homeowners bulbs contribute.

I am all in favour of eradicating the lot frankly.

The message
from The Natural Philosopher contains these words:

yes, but the average town has about ten times as much street lighting
that is on ALL NIGHT as the homeowners bulbs contribute.

I am all in favour of eradicating the lot frankly.

I'd gladly get rid of streetlighting. Better I'd like to get rid of the
lights on the side of the new White Elephant Centre a hundred yards or
so away. They shine outwards not downwards and are vile.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Fri, 25 Aug 2006 10:04:43 +0100, "Christian McArdle"
wrote:

There's something that could do with creative regulation, why do PCs
use 50-100W when laptops use 15W (including the screen!).

The desktops frequently don't use 50-100W if set up properly with the energy
saving options implemented. Set it to halt the processor on idle, shut off
the screen and power down the disks and it won't eat that much more than a
laptop.

I'm not so sure, I made a SFF PC with a fairly modest 1.6G CPU,
normally it idled at 60W, with maximum underclocking/undervolting that
dropped to ~40W.

Then I got a 1.7G Centrino laptop, when the screen was off it idled at
10W!

For a PC that's on 24/7 and needs to be silent, IMHO it can work out
cheaper to get a laptop that uses little power than a desktop with all
the mods to make it as quiet as possible.

With firewire and a big external disc it would make a good home server
too. Plus it has a built in UPS

cheers,
Pete.

Christian McArdle wrote:
Domestic fuel consumption is actually far greater than all the electricity
consumption of fuel put together, and transport exceeds them both.

Perhaps that is because of lack of insulation. All the houses I have run
have had electricity consumption and gas consumption at a similar cost. I
don't recognise the heating being considerably more than electricity.

But the cost of electricity (per kWh) is greater than Gas (per kWh) so
though I would agree, from my experience that the two bills may be
similar that is not the same as same energy consumption.

Over the past two years extensive renovation changed my pattern of
energy use: I have probably saved £10 per quarter just by installing a
boiler that /does not/ have a pilot light. Using a combi rather than
electric shower should make a difference to relative rates of
consumption though it is difficult to tell so far.

On 25 Aug 2006 04:40:13 -0700 someone who may be
wrote this:-

Note that replacing _working_ CRT monitors with LCDs is
counterproductive energywise. Although it reduces electricity use, the
money cost and energy cost of buying the monitor are never paid back by
these reductions. So those of us with an army of CRTs should ideally
keep them.

Indeed. Only when they have hard to fix faults is it worth replacing
them.



--
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

Christian McArdle wrote:

And the misleading power equivalance figures.

I'm not sure they are that misleading. It is just that they take a few
minutes to warm up.

Christian.

....up to their misleading level. Equivalent powers are quoted compared
to non-standard gls, though they like to phrase it so people think
otherwise. Real life equivalence ratio of 4 is closer the mark. This is
one of the reasons first time users think they make the place look
grotty, theyre putting the wrong power bulb in.


NT

Fash wrote:

Haitz law says that LED brightness doubles ~every 2 years and in fact
it's getting quicker than that.

Haitz law is not a law of course. Really we'll just have to wait and
see. It would be unrealistic to expect no ceiling to LED efficacy, and
as of now we simply dont know where or when that ceiling will occur.


LED products are already in the market
place in niche areas

yes, some of which they suit fine. But not general lighting.

such as architectural lighting and signalling.
Also they are getting pushed into larger and larger LCDs as a result of
regulation. In the automotive area the drive to remove mercury is now
quite serious and the EU and other regulatory bodies are able to skew
normal market economics resulting in earlier tipping points.

none of which is general lighting

One of the
big reasons LEDs don't compete is that the volumes are too small AND
the companies producing them are still working on high margins. This is
not sustainable as Taiwan and China (who generally care less about
intellectual property) move into the market prices will drop
significantly. At the moment ~1/2 the cost of a white LED is license
fees for other peoples patents. This means you're total energy market
is not as accurate as you might think although clearly lawyers do
generate lots of hot air.

will this make enough difference?


The other thing you're wrong or at least over egging is improvements in
fluorescent technology. There has been very little improvement in CCFL
over the last 20 years and newer developments like HCFL and EEFL are
not more efficient they just offer control benefits around things like
dimming and flashing which are not important for general lighting.

These technologies are not what I refer to. The newer techs used in
general lighting are much further back on the curve, and are
triphosphors, electronic ballasts, spiral tubes and electrodeless
lamps. These are the ones relevant to general lighting today.

Fl tech has gone through the same piecemeal improvement process as
LEDs, starting back in the late 1930s when fl lighting began. And its
continuing.

LEDs may overtake fl yet for general lighting, and equally they may
fail to, but 2 things are for su
- for general lighting today LED is not a reasonable choice.
- LEDs have some way to go to catch up with todays fl technology.


NT

In article . com,
"Fash" writes:
Haitz law says that LED brightness doubles ~every 2 years and in fact
it's getting quicker than that. LED products are already in the market
place in niche areas such as architectural lighting and signalling.
Also they are getting pushed into larger and larger LCDs as a result of
regulation. In the automotive area the drive to remove mercury is now
quite serious and the EU and other regulatory bodies are able to skew
normal market economics resulting in earlier tipping points. One of the
big reasons LEDs don't compete is that the volumes are too small AND
the companies producing them are still working on high margins. This is
not sustainable as Taiwan and China (who generally care less about
intellectual property) move into the market prices will drop
significantly. At the moment ~1/2 the cost of a white LED is license
fees for other peoples patents. This means you're total energy market
is not as accurate as you might think although clearly lawyers do
generate lots of hot air.

This does mean we can predict the point at which LED lighting
becomes a viable consumer product -- it's when the patents run
out. So take a peak performing LED today, and that product could
become a mass consumer product in about 20 years time.

A second fundamental problem with LEDs is their inability to work
at the same temperatures as most existing light sources, which
means they have to be very much more efficient (which they aren't)
or much bigger (to dissipate the heat whilst maintaining a low
temperature).

The other thing you're wrong or at least over egging is improvements in
fluorescent technology. There has been very little improvement in CCFL
over the last 20 years and newer developments like HCFL and EEFL are
not more efficient they just offer control benefits around things like
dimming and flashing which are not important for general lighting.

There's a factor of 2 performance improvement in fluorescent
phosphors which is awaiting whoever first works around Stokes
shift. I suspect we will start seeing minature metal halide
lamps as contenders to halogen downlighters in the next few
years too as the HID headlamp patents expire. Other lamp
technologies aren't going to sit still for the next 20 years
just so LEDs can become viable commodities.

--
Andrew Gabriel

...up to their misleading level. Equivalent powers are quoted compared
to non-standard gls, though they like to phrase it so people think
otherwise. Real life equivalence ratio of 4 is closer the mark. This is
one of the reasons first time users think they make the place look
grotty, theyre putting the wrong power bulb in.

People's experience may also vary according to their local supply potential.
Incandescent bulbs are very sensitive to voltage. People living in a house
with 250V will get a much brighter output from a "100W" incandescent than
people living with 230V. The CFLs won't vary nearly so much.

Christian.

yes, but the average town has about ten times as much street lighting that
is on ALL NIGHT as the homeowners bulbs contribute.

Street lighting could be much better designed. They should be made to point
downwards, both to save energy and to make the sky darker. Remember, though,
that those sodium lights are much more efficient that even fluorescent
lighting (they give out twice the light) and there is probably less than one
street light for every house, even given all the non-residential roads.

Christian.