The recent discussion about lights has pricked my conscience (again!)
about the workshop lights, some of which are on several hours per day. I
have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
switchable in pairs.
Am I correct that, for equivalent light output, the LEDs consume about
half the power of fluorescents?
If that's correct, and assuming that all the lights are on for a total
of 4 hours per day on average, it seems that I could save roughly
0.6kWh/day by changing to LEDs. If an LED tube is about £5 and
electricity is about 50p/kWh then break-even is in less than 20 days.
This is all very rough, but is there a glaring error?

On 8/3/2023 10:21 AM, nothanks@aolbin.com wrote:
> The recent discussion about lights has pricked my conscience (again!) about the workshop lights, some of which are on several hours per day. I have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights, switchable in pairs.
> Am I correct that, for equivalent light output, the LEDs consume about half the power of fluorescents?
> If that's correct, and assuming that all the lights are on for a total of 4 hours per day on average, it seems that I could save roughly 0.6kWh/day by changing to LEDs. If an LED tube is about £5 and electricity is about 50p/kWh then break-even is in less than 20 days.
> This is all very rough, but is there a glaring error?

"Fluorescent lights produce between 50 and 100 lumens per watt.
By comparison, LEDs can produce roughly 130 lumens per watt."

I would say a more conservative estimate, is LEDs are 60 to 130 lumens per watt.

There are still lots of shit 60-80 lumen per watt LEDs in the channel.
Quoting "lab numbers" (130 or 200) is cheating, if they aren't really
in production, or, are more expensive. Even if the payback period
was longer, maybe the expensive LEDs would be better in the long run.
The higher output LEDs have fewer crystalline defects (disorder in crystal).
Eventually LEDs will reach a "maximum" output some day, but we may not be there yet.

The LED market, is to some extent siloed. You may not find any Nichia LEDs
in the lamps you buy (Japan?). Maybe they're Cree. It's possible the efficiency
of each of those companies, is different.

The effectiveness of LEDs, depends a lot on the luminaire design. The square
LED panels might be better from an absolute point of view, than sticking a
LED tube in a florry fixture. (The LED tube should send out light on 180 degrees
of the surface, rather than 360 degrees. The LEDs are not inherently 360 degree
devices, although you could put them on either side of a PCB if you wanted.)

I learned about LEDs, when I built my own bicycle light. I started with
a single "power" LED. I used a commercial grade reflector (polycarbonate,
aluminized) and fittings. The light was... terrible. Next, I built an array illuminator,
48 LEDs fitted with 15 degree lenses on each LED by the
manufacturer. That produces great light. Part of the reason
that works, is there is less "phosphor smothering" when using
large numbers of small LEDs. The operating temperature of the
LEDs can also be a bit lower that way. (One of the reasons I tried this,
is I ordered a "bag of LEDs" at the same time as I ordered the power LEDs,
and the bag of LEDs was just going into one of my parts bins for later.
Since the power LED was a dismal flop, that bag of LEDs was just
"staring me in the face".)

To some extent, you have to try these things out, and
see what you think.

Let's say that LEDs come with the following colour temperatures.

2500 degrees -- reading light for living room (least efficient bulb is the result)
3500 \___ -- slightly bluer light for shop
4500 /
9000 -- extremely blue, suited to bicycle lights (most efficient, not pleasant)

The next item is a single point specification for the colour balance.
A CRI of 80 is so-so. A CRI of 100 would be an emulation of a
black body emitter (like an incandescent).

"Incandescent and halogen light sources have a CRI of 100.
Typically, light sources with a CRI of 80 to 90 are regarded as good
and those with a CRI of 90+ are excellent! The general rule is: The higher
the CRI, the better the color rendering capacity. CRI is
independent of color temperature." [ See picture of four apples... ]

( https://www.westinghouselighting.com/lighting-education/color-rendering-index-cri.aspx )

Expecting a single point CRI number to reflect colour balance is never going
to work. There may be an alternate proposal to CRI, but the thing is,
people still make really bad LED light bulbs that will "knock an eye out",
whether we have a CRI value or not. I have a LED bulb here that is "mush"
and the light, while bright, is awful for any purpose.

To some extent then, you have to get a sample unit of whatever
you plan on using, and see for yourself.

In Dubai, they like smaller emitters for their efficiency. But one
of the prices for doing this, is the cost of fixturing. The electrician
would be there all week, wiring up all those sockets. The stand alone
Dubai lamps are low power, like 2W or 3W of mains power. The fake Dubai
lamps we can buy here, are SMPS based, and not the (lightly regulated)
capacitive dropper of the Dubai lamp. Dubai lamps use twice the filament
chains of LEDs that other filament chain lamps use.

https://image.khaleejtimes.com/?uuid=e851d3c1-3dd9-54b0-8dc9-f8bc20db735f&function=cropresize&type=preview&source=false&q=75&crop_w=0.99999&crop_h=0.84383&x=0&y=0&width=1200&height=675

These bulbs are more efficient than the ones we get, cheaply, at the store.
But then you'd have quite a wiring job ahead of you (many sockets).

https://hackaday.com/2021/01/17/leds-from-dubai-the-royal-lights-you-cant-buy/

Paul

On 03/08/2023 in message <kj1rfvFdml2U1@mid.individual.net>
nothanks@aolbin.com wrote:

>The recent discussion about lights has pricked my conscience (again!)
>about the workshop lights, some of which are on several hours per day. I
>have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
>switchable in pairs.
>Am I correct that, for equivalent light output, the LEDs consume about
>half the power of fluorescents?
>If that's correct, and assuming that all the lights are on for a total of
>4 hours per day on average, it seems that I could save roughly 0.6kWh/day
>by changing to LEDs. If an LED tube is about £5 and electricity is about
>50p/kWh then break-even is in less than 20 days.
>This is all very rough, but is there a glaring error?

My 5' LED light for the kitchen arrived this afternoon. I will have to see
what the light is like but can anybody tell me how I can balance it on my
head while I wire it up please?

--
Jeff Gaines Dorset UK
Tell me what you need, and I'll tell you how to get along without it.

On 03/08/2023 17:03, Jeff Gaines wrote:
> On 03/08/2023 in message <kj1rfvFdml2U1@mid.individual.net>
> nothanks@aolbin.com wrote:
>
>> The recent discussion about lights has pricked my conscience (again!)
>> about the workshop lights, some of which are on several hours per day.
>> I have 2 pairs of modern 6ft lights and one pair of elderly 5ft
>> lights, switchable in pairs.
>> Am I correct that, for equivalent light output, the LEDs consume about
>> half the power of fluorescents?
>> If that's correct, and assuming that all the lights are on for a total
>> of 4 hours per day on average, it seems that I could save roughly
>> 0.6kWh/day by changing to LEDs. If an LED tube is about £5 and
>> electricity is about 50p/kWh then break-even is in less than 20 days.
>> This is all very rough, but is there a glaring error?
>
> My 5' LED light for the kitchen arrived this afternoon. I will have to
> see what the light is like but can anybody tell me how I can balance it
> on my head while I wire it up please?

I think the idea is you screw it to the ceiling before you try wiring it!

(and if that is the hard bit - then one smallish screw placed through a
hole somewhere near the middle - with the end of the driver poked into
the head holding the screw in place. Now offer the thing up to the
ceiling and drive the screw enough to take the strain. You can now take
your time fixing it properly).

You could also try the "dead man" prop idea:

https://wiki.diyfaq.org.uk/index.php/Dead_man_prop

--
Cheers,

John.

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

On 03/08/2023 15:21, nothanks@aolbin.com wrote:
> The recent discussion about lights has pricked my conscience (again!)
> about the workshop lights, some of which are on several hours per day. I
> have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
> switchable in pairs.
> Am I correct that, for equivalent light output, the LEDs consume about
> half the power of fluorescents?

These examples use tubes from TLC Direct.

Their 5ft and 6ft triphosphor T8 fluorescent tubes are 58W and 70W
respectively. The light output is 5200 and 5600 lumens. That's 90 and 80
lumens per watt. The total light output for 2 x 5ft and 2 x 6ft tubes
would be 21800 lumens.

For comparison, look at their LEDlite led "fluorescent tubes". The 5ft
and 6ft tubes are both rated at 24W and 4000 lumens, so providing 167
lumens per watt. On that basis they are twice as efficient (the real
fluorescents would provide light over 360°; the led equivalents are said
to provide 330°, so they're essentially equivalent). Strangely, the
LEDlite website says the 24W tubes provide only 3230 lumens, or 135
lumens per watt.

> If that's correct, and assuming that all the lights are on for a total
> of 4 hours per day on average, it seems that I could save roughly
> 0.6kWh/day by changing to LEDs. If an LED tube is about £5 and
> electricity is about 50p/kWh then break-even is in less than 20 days.
> This is all very rough, but is there a glaring error?

To get 21800 lumens from the led tubes, you'd require 5.5 tubes - so 5
tubes in practice. The consumption of 5 tubes is 5 x 24W, or 120W. For 4
hours, that's 480Wh. The fluorescents would use 256W, or 1024Wh over the
same period. So, overall, the leds would use 0.5kWh less per day than
the fluorescents. That's 20p/day based on 40p/kWh (that might be a bit
on the high side, as mine is currently 37p/kWh). At TLC, 3 x 5ft leds
and 2 x 6ft leds would cost about £51 + vat; let's say £63. On that
basis, it would take £63/£0.20 days, or around 45 weeks to save enough
electricity to pay for the tubes. You'd also have to factor in another
5ft tube holder for the extra tube, or put up with 25% less light from 4
tubes.

--

Jeff

On 03/08/2023 in message <uagkiq$r1v7$1@dont-email.me> John Rumm wrote:

>I think the idea is you screw it to the ceiling before you try wiring it!
>
>(and if that is the hard bit - then one smallish screw placed through a
>hole somewhere near the middle - with the end of the driver poked into the
>head holding the screw in place. Now offer the thing up to the ceiling and
>drive the screw enough to take the strain. You can now take your time
>fixing it properly).
>
>You could also try the "dead man" prop idea:
>
>https://wiki.diyfaq.org.uk/index.php/Dead_man_prop

The wiring is behind it so I have to connect it first. It goes into spring
clips so the plan is fix them to the ceiling, balance the light on a step
that allows the flex to reach the choc-block (that was used by the
spotlights) then clip it up. We'll have to see :-)

--
Jeff Gaines Dorset UK
Roses are #FF0000, violets are #0000FF
if you can read this, you're a nerd 10.

On 03/08/2023 19:22, Jeff Gaines wrote:
> On 03/08/2023 in message <uagkiq$r1v7$1@dont-email.me> John Rumm wrote:
>
>> I think the idea is you screw it to the ceiling before you try wiring it!
>>
>> (and if that is the hard bit - then one smallish screw placed through
>> a hole somewhere near the middle - with the end of the driver poked
>> into the head holding the screw in place. Now offer the thing up to
>> the ceiling and drive the screw enough to take the strain. You can now
>> take your time fixing it properly).
>>
>> You could also try the "dead man" prop idea:
>>
>> https://wiki.diyfaq.org.uk/index.php/Dead_man_prop
>
> The wiring is behind it so I have to connect it first. It goes into
> spring clips so the plan is fix them to the ceiling, balance the light
> on a step that allows the flex to reach the choc-block (that was used by
> the spotlights) then clip it up. We'll have to see :-)

If the wiring is in the ceiling void, there is no harm in extending the
switched live cable a bit to make it easier. You can push the spare into
the ceiling when done. Failing that place a fixing in the ceiling such
that it's hole will later be hidden by the light. Attach a strap of some
kind to that to hold the fitting while you wire.

--
Cheers,

John.

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

On 03/08/2023 21:47, John Rumm wrote:
> On 03/08/2023 19:22, Jeff Gaines wrote:
>> On 03/08/2023 in message <uagkiq$r1v7$1@dont-email.me> John Rumm wrote:
>>
>>> I think the idea is you screw it to the ceiling before you try wiring
>>> it!
>>>
>>> (and if that is the hard bit - then one smallish screw placed through
>>> a hole somewhere near the middle - with the end of the driver poked
>>> into the head holding the screw in place. Now offer the thing up to
>>> the ceiling and drive the screw enough to take the strain. You can
>>> now take your time fixing it properly).
>>>
>>> You could also try the "dead man" prop idea:
>>>
>>> https://wiki.diyfaq.org.uk/index.php/Dead_man_prop
>>
>> The wiring is behind it so I have to connect it first. It goes into
>> spring clips so the plan is fix them to the ceiling, balance the light
>> on a step that allows the flex to reach the choc-block (that was used
>> by the spotlights) then clip it up. We'll have to see :-)
>
> If the wiring is in the ceiling void, there is no harm in extending the
> switched live cable a bit to make it easier. You can push the spare into
> the ceiling when done. Failing that place a fixing in the ceiling such
> that it's hole will later be hidden by the light. Attach a strap of some
> kind to that to hold the fitting while you wire.
>

to be honest, the new LED battens and plastic casings are much lighter
than the old flourries with their heavy iron framed ballasts and metal
casings.....

I think the other thing to bear in mind is that the traditional tubes lose
efficiency over time, whereas as far as I can tell, LEDs do not. Of cours
this depends on the way they make the light, I believe some use UV leds
which makes the phosphor light up at visible light in a similar way to
traditional tubes using ionised gass, but the driving of the older tubes is
less efficient as well, unless its an electronic ballast.
I of couse only use light when a sighted person comes around, so there
seems little point in changing until it comes time to replace something,
when the light panels start to look attractive providing the reliability is
there. If you don't want to have to redecorate the sealing however the LED
tubes is the only game in town as real tubes are like hens teeth.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Jeff Layman" <Jeff@invalid.invalid> wrote in message
news:uagqfn$ro7v$1@dont-email.me...
> On 03/08/2023 15:21, nothanks@aolbin.com wrote:
>> The recent discussion about lights has pricked my conscience (again!)
>> about the workshop lights, some of which are on several hours per day. I
>> have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
>> switchable in pairs.
>> Am I correct that, for equivalent light output, the LEDs consume about
>> half the power of fluorescents?
>
> These examples use tubes from TLC Direct.
>
> Their 5ft and 6ft triphosphor T8 fluorescent tubes are 58W and 70W
> respectively. The light output is 5200 and 5600 lumens. That's 90 and 80
> lumens per watt. The total light output for 2 x 5ft and 2 x 6ft tubes
> would be 21800 lumens.
>
> For comparison, look at their LEDlite led "fluorescent tubes". The 5ft and
> 6ft tubes are both rated at 24W and 4000 lumens, so providing 167 lumens
> per watt. On that basis they are twice as efficient (the real fluorescents
> would provide light over 360�; the led equivalents are said to provide
> 330�, so they're essentially equivalent). Strangely, the LEDlite website
> says the 24W tubes provide only 3230 lumens, or 135 lumens per watt.
>
>> If that's correct, and assuming that all the lights are on for a total
>> of 4 hours per day on average, it seems that I could save roughly
>> 0.6kWh/day by changing to LEDs. If an LED tube is about �5 and
>> electricity is about 50p/kWh then break-even is in less than 20 days.
>> This is all very rough, but is there a glaring error?
>
> To get 21800 lumens from the led tubes, you'd require 5.5 tubes - so 5
> tubes in practice. The consumption of 5 tubes is 5 x 24W, or 120W. For 4
> hours, that's 480Wh. The fluorescents would use 256W, or 1024Wh over the
> same period. So, overall, the leds would use 0.5kWh less per day than the
> fluorescents. That's 20p/day based on 40p/kWh (that might be a bit on the
> high side, as mine is currently 37p/kWh). At TLC, 3 x 5ft leds and 2 x 6ft
> leds would cost about �51 + vat; let's say �63. On that basis, it would
> take �63/�0.20 days, or around 45 weeks to save enough electricity to pay
> for the tubes. You'd also have to factor in another 5ft tube holder for
> the extra tube, or put up with 25% less light from 4 tubes.
>
> --
>
> Jeff
>

On 03/08/2023 16:36, Paul wrote:

> 2500 degrees -- reading light for living room (least efficient bulb is the result)

That's down to your personal preference.

Those with ageing eyes may find that something towards the blue ('cool'
or LEDs sold as daylight) give a page better contrast for reading.

> 3500 \___ -- slightly bluer light for shop
> 4500 /

Also for work areas such as kitchens or probably workshops.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 03/08/2023 19:22, Jeff Gaines wrote:
> On 03/08/2023 in message <uagkiq$r1v7$1@dont-email.me> John Rumm wrote:
>
>> I think the idea is you screw it to the ceiling before you try wiring it!
>>
>> (and if that is the hard bit - then one smallish screw placed through
>> a hole somewhere near the middle - with the end of the driver poked
>> into the head holding the screw in place. Now offer the thing up to
>> the ceiling and drive the screw enough to take the strain. You can now
>> take your time fixing it properly).
>>
>> You could also try the "dead man" prop idea:
>>
>> https://wiki.diyfaq.org.uk/index.php/Dead_man_prop
>
> The wiring is behind it so I have to connect it first. It goes into
> spring clips so the plan is fix them to the ceiling, balance the light
> on a step that allows the flex to reach the choc-block (that was used by
> the spotlights) then clip it up. We'll have to see :-)
>

Replace the chock bloc with Wago connectors. Flipping down a lever is
much easier and faster than trying to do the screw up.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 03/08/2023 19:08, Jeff Layman wrote:
> On 03/08/2023 15:21, nothanks@aolbin.com wrote:
>> The recent discussion about lights has pricked my conscience (again!)
>> about the workshop lights, some of which are on several hours per day. I
>> have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
>> switchable in pairs.
>> Am I correct that, for equivalent light output, the LEDs consume about
>> half the power of fluorescents?
>
> These examples use tubes from TLC Direct.
>
> Their 5ft and 6ft triphosphor T8 fluorescent tubes are 58W and 70W
> respectively. The light output is 5200 and 5600 lumens. That's 90 and 80
> lumens per watt. The total light output for 2 x 5ft and 2 x 6ft tubes
> would be 21800 lumens.
>
> For comparison, look at their LEDlite led "fluorescent tubes". The 5ft
> and 6ft tubes are both rated at 24W and 4000 lumens, so providing 167
> lumens per watt. On that basis they are twice as efficient (the real
> fluorescents would provide light over 360°; the led equivalents are said
> to provide 330°, so they're essentially equivalent). Strangely, the
> LEDlite website says the 24W tubes provide only 3230 lumens, or 135
> lumens per watt.
>
>> If that's correct, and assuming that all the lights are on for a total
>> of 4 hours per day on average, it seems that I could save roughly
>> 0.6kWh/day by changing to LEDs. If an LED tube is about £5 and
>> electricity is about 50p/kWh then break-even is in less than 20 days.
>> This is all very rough, but is there a glaring error?
>
> To get 21800 lumens from the led tubes, you'd require 5.5 tubes - so 5
> tubes in practice. The consumption of 5 tubes is 5 x 24W, or 120W. For 4
> hours, that's 480Wh. The fluorescents would use 256W, or 1024Wh over the
> same period. So, overall, the leds would use 0.5kWh less per day than
> the fluorescents. That's 20p/day based on 40p/kWh (that might be a bit
> on the high side, as mine is currently 37p/kWh). At TLC, 3 x 5ft leds
> and 2 x 6ft leds would cost about £51 + vat; let's say £63. On that
> basis, it would take £63/£0.20 days, or around 45 weeks to save enough
> electricity to pay for the tubes. You'd also have to factor in another
> 5ft tube holder for the extra tube, or put up with 25% less light from 4
> tubes.
>
Just spotted that I c*cked-up by only costing one tube (and probably
under-estimated its cost) :-( Although underlying electricity costs are
high at the moment they will (probably?) fall.
A bit more poking-around suggests: that T5 tubes give about 100 Lumens/W
and T8s around 80 Lumens/W, so size matters!
It's hard to find believable accurate info about life and efficiency,
but the bottom line seems clear: even for relatively high usage there
isn't a strong economic argument for replacing serviceable fluorescents
with LEDs. Replacing failed units with LED is, obviously, a no-brainer.

Jeff Layman wrote:

> the leds would use 0.5kWh less per day than the fluorescents. That's
> 20p/day based on 40p/kWh (that might be a bit on the high side, as mine
> is currently 37p/kWh).

Yes that's high, I currently pay EDF 29.5p and BG 31.0p

On 06/08/2023 11:40, Andy Burns wrote:
> Jeff Layman wrote:
>
>> the leds would use 0.5kWh less per day than the fluorescents. That's
>> 20p/day based on 40p/kWh (that might be a bit on the high side, as mine
>> is currently 37p/kWh).
>
> Yes that's high, I currently pay EDF 29.5p and BG 31.0p

I was looking at an old bill! Elec is currently 31.9p/kWh (that includes
5% vat).

--

Jeff

On 06/08/2023 10:48, nothanks@aolbin.com wrote:

> Just spotted that I c*cked-up by only costing one tube (and probably
> under-estimated its cost) :-( Although underlying electricity costs are
> high at the moment they will (probably?) fall.
> A bit more poking-around suggests: that T5 tubes give about 100 Lumens/W
> and T8s around 80 Lumens/W, so size matters!
> It's hard to find believable accurate info about life and efficiency,
> but the bottom line seems clear: even for relatively high usage there
> isn't a strong economic argument for replacing serviceable fluorescents
> with LEDs. Replacing failed units with LED is, obviously, a no-brainer.

I think that sums it up well. My cost estimate of 37p/kWh should have
been 32p/kWh (will it fall more, or is that the final reduction we can
expect?), and looking at various sites appears to suggest that the led
fluos would be giving nearer to 120 lumen/watt rather than 150. in fact,
Philips state about 100l/W - so not that much more than a standard fluo.
On that basis, simply replacing working fluos with led equivalents makes
little sense.

--

Jeff

On 06/08/2023 13:19, Jeff Layman wrote:

> 32p/kWh (will it fall more, or is that the final reduction we can expect?)

To a first approximation our electricity prices are driven by gas
prices, and they (wholesale) are now below what they were when Vlad
started his little exercise ...

On 06/08/2023 14:49, Andy Burns wrote:
> On 06/08/2023 13:19, Jeff Layman wrote:
>
>> 32p/kWh (will it fall more, or is that the final reduction we can
>> expect?)
>
> To a first approximation our electricity prices are driven by gas
> prices, and they (wholesale) are now below what they were when Vlad
> started his little exercise ...
>

though we weren't then paying for Bulb and Ofgem's other lesser
disasters, and there is pressure on Ofgem to switch the burden of that
and other fixed and mixed costs from standing charges to unit rates

--
Robin
reply-to address is (intended to be) valid

On 06/08/2023 16:49, Robin wrote:
> On 06/08/2023 14:49, Andy Burns wrote:
>> On 06/08/2023 13:19, Jeff Layman wrote:
>>
>>> 32p/kWh (will it fall more, or is that the final reduction we can
>>> expect?)
>>
>> To a first approximation our electricity prices are driven by gas
>> prices, and they (wholesale) are now below what they were when Vlad
>> started his little exercise ...
>>
>
> though we weren't then paying for Bulb and Ofgem's other lesser
> disasters, and there is pressure on Ofgem to switch the burden of that
> and other fixed and mixed costs from standing charges to unit rates

Which would hit families needing to do a lot of washing, drying and
heating and elderly people needing extra, often electric, heating in the
colder months.

On 06/08/2023 10:48, nothanks@aolbin.com wrote:
> the bottom line seems clear: even for relatively high usage there isn't
> a strong economic argument for replacing serviceable fluorescents with
> LEDs. Replacing failed units with LED is, obviously, a no-brainer.

I came to that conclusion as well. In respect of the long tubes anyway.
CFLS proved so unreliable, dim , and short lived that they got replaced
irrespective of whether they failed or not.

The colour of fluoro light is is not my favourite, but for work areas,m
who cares?

LEDS now seem to be getting more and more reliable. I have had a fair
few pop, but the remainder are rock solid.

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On 06/08/2023 13:19, Jeff Layman wrote:

> I think that sums it up well. My cost estimate of 37p/kWh should have
> been 32p/kWh (will it fall more, or is that the final reduction we can
> expect?),

Nuclear power stations sell to the grid currently at around 4-5p.
Hinkley point is guaranteed around 9.5p I think. Drax wood is similar
to coal at the 4-5p mark I think

Its gas and renewables that together drive the price up.

--
Labour - a bunch of rich people convincing poor people to vote for rich
people by telling poor people that "other" rich people are the reason
they are poor.

Peter Thompson

On 06/08/2023 14:49, Andy Burns wrote:
> On 06/08/2023 13:19, Jeff Layman wrote:
>
>> 32p/kWh (will it fall more, or is that the final reduction we can
>> expect?)
>
> To a first approximation our electricity prices are driven by gas
> prices, and they (wholesale) are now below what they were when Vlad
> started his little exercise ...
>
No, they are now driven by green taxes and renewable subsidies.

--
Labour - a bunch of rich people convincing poor people to vote for rich
people by telling poor people that "other" rich people are the reason
they are poor.

Peter Thompson

The Natural Philosopher wrote:

> CFLS proved so unreliable, dim , and short lived that they got replaced
> irrespective of whether they failed or not.

Mine got relegated to the loft.

> LEDS now seem to be getting more and more reliable. I have had a fair
> few pop, but the remainder are rock solid.

Agreed, I had a few "China specials" that didn't last long, but since
models that are genuinely equivalent to 100W bulbs arrived, they've been
fine.

Just the fluoro tubes in garage/shed left now, some are sluggish to
start when cold, but they're used such short time it doesn't justify
changing them to LED.

On 07/08/2023 11:04, Andy Burns wrote:
> The Natural Philosopher wrote:
>
>> CFLS proved so unreliable, dim , and short lived that they got
>> replaced irrespective of whether they failed or not.
>
> Mine got relegated to the loft.
My loft has the only fluorescent tubes in the property!

>
>> LEDS now seem to be getting more and more reliable. I have had a fair
>> few pop, but the remainder are rock solid.
>
> Agreed, I had a few "China specials" that didn't last long, but since
> models that are genuinely equivalent to 100W bulbs arrived, they've been
> fine.
>
> Just the fluoro tubes in garage/shed left now, some are sluggish to
> start when cold, but they're used such short time it doesn't justify
> changing them to LED.

Exactly. When running well (enough) leave well, alone.

--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

On Sunday, 6 August 2023 at 10:48:09 UTC+1, noth...@aolbin.com wrote:
> On 03/08/2023 19:08, Jeff Layman wrote:
> > On 03/08/2023 15:21, noth...@aolbin.com wrote:
> >> The recent discussion about lights has pricked my conscience (again!)
> >> about the workshop lights, some of which are on several hours per day. I
> >> have 2 pairs of modern 6ft lights and one pair of elderly 5ft lights,
> >> switchable in pairs.
> >> Am I correct that, for equivalent light output, the LEDs consume about
> >> half the power of fluorescents?
> >
> > These examples use tubes from TLC Direct.
> >
> > Their 5ft and 6ft triphosphor T8 fluorescent tubes are 58W and 70W
> > respectively. The light output is 5200 and 5600 lumens. That's 90 and 80
> > lumens per watt. The total light output for 2 x 5ft and 2 x 6ft tubes
> > would be 21800 lumens.
> >
> > For comparison, look at their LEDlite led "fluorescent tubes". The 5ft
> > and 6ft tubes are both rated at 24W and 4000 lumens, so providing 167
> > lumens per watt. On that basis they are twice as efficient (the real
> > fluorescents would provide light over 360°; the led equivalents are said
> > to provide 330°, so they're essentially equivalent). Strangely, the
> > LEDlite website says the 24W tubes provide only 3230 lumens, or 135
> > lumens per watt.
> >
> >> If that's correct, and assuming that all the lights are on for a total
> >> of 4 hours per day on average, it seems that I could save roughly
> >> 0.6kWh/day by changing to LEDs. If an LED tube is about £5 and
> >> electricity is about 50p/kWh then break-even is in less than 20 days.
> >> This is all very rough, but is there a glaring error?
> >
> > To get 21800 lumens from the led tubes, you'd require 5.5 tubes - so 5
> > tubes in practice. The consumption of 5 tubes is 5 x 24W, or 120W. For 4
> > hours, that's 480Wh. The fluorescents would use 256W, or 1024Wh over the
> > same period. So, overall, the leds would use 0.5kWh less per day than
> > the fluorescents. That's 20p/day based on 40p/kWh (that might be a bit
> > on the high side, as mine is currently 37p/kWh). At TLC, 3 x 5ft leds
> > and 2 x 6ft leds would cost about £51 + vat; let's say £63. On that
> > basis, it would take £63/£0.20 days, or around 45 weeks to save enough
> > electricity to pay for the tubes. You'd also have to factor in another
> > 5ft tube holder for the extra tube, or put up with 25% less light from 4
> > tubes.
> >
> Just spotted that I c*cked-up by only costing one tube (and probably
> under-estimated its cost) :-( Although underlying electricity costs are
> high at the moment they will (probably?) fall.
> A bit more poking-around suggests: that T5 tubes give about 100 Lumens/W
> and T8s around 80 Lumens/W, so size matters!
> It's hard to find believable accurate info about life and efficiency,
> but the bottom line seems clear: even for relatively high usage there
> isn't a strong economic argument for replacing serviceable fluorescents
> with LEDs. Replacing failed units with LED is, obviously, a no-brainer.

Those lm/w figures are for new fl tubes, over decades they fall a lot. Last time I replaced fluoros their output was way down, but no-one realised until the new LEDs went in.

On 12/08/2023 21:29, Animal wrote:

> Those lm/w figures are for new fl tubes, over decades they fall a lot. Last time I replaced fluoros their output was way down, but no-one realised until the new LEDs went in.

Many years ago at my former place of work they replaced all the fluoro
tubes with new fluoro tubes over the weekend. When we came in on the
Monday the office/factory was very much brighter!

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk