Talk:LED lamp

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Better lamp[edit]

Impressive! This Philips bulb is much better than the one in the table. I was going to add these numbers

2.49 8.5 800 94 2700 80 10,000 5 48 58 63

but the "limit 10 per order" pushes me not to. At the amazon price, though, it still beats the other bulbs by a significant margin. So should we replace the extant Philips bulb, using the Amazon pricing or the special deal at The Home Depot? Calculation for last row (Total cost per 860 lumens over 20 years @ 13 cents/kWh & @ 6 hours/day) : (40*13/11*1.02+4.97*2)*860/800=62.52 (40*13/11*1.02+12*2)*860/800=77.63 --Elvey(tc) 15:35, 7 May 2015 (UTC)

Wikipedia should not be a parts catalog nor a sales brochure. Although we may list "typical" prices for things it should not be specific to any vendor, "special deal" or not. Jeh (talk) 16:21, 7 May 2015 (UTC)
Agreed; let's update it and go with the typical pricing, thus:
6 8.5 800 94 2700 80 10,000 5 48 72 77
--Elvey(tc) 04:55, 16 May 2015 (UTC)
I just reverted a change that replaced the typical pricing (which I updated a few days ago) with the special deal pricing - despite the above consensus to use typical pricing (which already makes this product the price leader), and made what seems a wrong replacement of 2 with 5 in terms of unit counts per 20 years.--Elvey(tc) 21:22, 24 May 2015 (UTC)
FFS! 4 bulbs needed for 20 years @ 6 hours/day, AFAICT. Not 5. WTF? --Elvey(tc) 06:04, 30 May 2015 (UTC)

Well, with your revert we now have the situation where different bulb types with identical 10,000 hour lives have a different number of bulbs to last 20 years, which is simply wrong! Also pre-revert we had the happy situation that all the long-life bulbs were replaced to give an identical 50,000 hours of life. Please rv your revert to get the table back into this happy situation. Thank. Rwendland (talk) 11:29, 30 May 2015 (UTC)

I think I see where we differ. I did my calculations based on 10,000 hour bulbs lasting 5 years @ 6 hours a day, hence 4 bulbs needed for 20 years @ 6 hours/day, as I said. I'm guessing you're saying 10,000 hour bulbs lasting just UNDER 5 years @ 6 hours a day, hence 5 bulbs needed for 20 years. Is that why we're disagreeing? Indeed, identical 10,000 hour lives have a different number of bulbs to last 20 years is simply wrong. Lifetimes are estimates, and we should be treating them as such, so I'd say it's more likely that 4 bulbs would be needed for 20 years @ 6 hours/day than 5. So I'm going to change the table to be consistent with that.
Also, there were some ">" in the table that were inappropriate; I removed 'em. --Elvey(tc) 23:21, 3 June 2015 (UTC)
Perhaps it's more appropriate to have non-integers for the average # of bulbs per 20 years. If you agree, feel free to make it so! --Elvey(tc) 23:31, 3 June 2015 (UTC)
Are we agreed - it's more appropriate to have non-integers for the average # of bulbs per 20 years? Not convinced the bulb just added adds to the article. Thoughts? The chart assumes only 1 will be needed for 20 years, but that's unlikely.--Elvey(tc) 09:17, 16 June 2015 (UTC)

Osram missing in the table[edit]

Why is the largest supplier of light solutions missing in the table? Schily (talk) 10:42, 4 June 2015 (UTC)

They're the biggest when it comes to LED lamps, which are the subject of this article? I'd guess Cree or Philips is. --Elvey(tc) 02:14, 5 June 2015 (UTC)
I've never seen Cree lamps in a retail store, so Cree seems to be far away from being a market leader. It may be that Cree is a local phenomenon in the US, but Osram acts worldwide and is much larger than Cree. Philips is large but not as large as Osram. From the presence in retail stores, I would guess that Philips is 1/2 to 2/3 of the size of Osram. In case you don't know: Osram is the company that invented the phoshor that made the white LEDs possible. Schily (talk) 09:45, 8 June 2015 (UTC)
The original reason for listing 3 LED bulbs was that there were 3 significantly different grades/specs of LEDs: generic/cheap, quality manufacturer giving better lumens/watt - Philips was the example, leading-tech bulb - expensive but best lumens/watt. Cree was the cheap one at one point so got named instead of "generic". Nowadays the performance of all 3 have become quite similar so we don't see much different in the spec, especially as the 9.4w Lenovation seems discontinued. I wonder if we should change to only list one representative LED bulb now, as they are so similar? Be easier to maintain one, and 3 does not give much extra info now. Rwendland (talk) 19:08, 8 June 2015 (UTC)
The article could be enhanced in general: Why not mention basic development milestones?
  • Telefunken made the first blue LEDs around 1980 (but they have been made from Silicon Carbide and as a result have been very expensive).
  • Nichia made the first cheap blue LEDs around 1994.
  • Fraunhofer IAF (Dr. Jürgen Schneider) made the first white LED using luninescence conversion around 1995.
  • Osram was a pioneer for the phosphor that allowed to make white LEDs for illumination purposes from blue LEDs and there was a long court case on the patents from Nichia and Osram [1] that started in 2001 because Osram did not pay for the Nichia cheap blue LED patent and Nichia did not pay for the Osram phohspor patents. The result of the case was that they both may continue not to pay, because both companies own the fundamemtal ideas that in common allow white LEDs. Schily (talk) 08:59, 9 June 2015 (UTC)
FYI, ideas per se are not patentable. Sounds like content for the article on LEDs, not this one on LED lamps. --Elvey(tc) 06:56, 17 June 2015 (UTC)
It seems that you did not read the article, otherwise you did know that it was talking about a patent process. Schily (talk) 09:53, 17 June 2015 (UTC)
I was in two hardware stores and a lighting store recently. All three had many Cree lamps. Let's not act based on guesses or anecdotes - yours or mine. --Elvey(tc) 04:35, 9 June 2015 (UTC)
But why then do you tell me the anecdote that you found cree lamps in a retail store? They are not sold in any retail store I did see for now. Osram however is dominant an omnipresent. Schily (talk) 08:26, 9 June 2015 (UTC)
Doesn't matter if I did or not; we should not act based on guesses or anecdotes - yours or mine. Not true: no Osram LED lamps when I was last at Home Depot. And virtually none (just 1 that's >1 watt) on their site. --Elvey(tc) 09:17, 16 June 2015 (UTC)
Well it may be that you can find some stores in a specific area on the world where your claim may be right. In general, you rather see Osram than Cree. Schily (talk) 09:57, 16 June 2015 (UTC)
Again, [citation needed].--Elvey(tc) 06:56, 17 June 2015 (UTC)
Wonderful! So you are willing to give sources on where the lamps in the table are available in retail stores? As this is not the US version of Wikipedia but the international one written in the English language but not assigned to a specific country, I propose to remove entries from the table for products that cannot be bought in a typical retail store in Europe. Schily (talk) 09:58, 18 June 2015 (UTC)

Table needs updating[edit]

The Philips bulb linked now says $8.18 for a 10.W 25,000 hour bulb all different values (except the item number). The Lenovation bulb linked is discontinued by that seller (I think), is 10.5W not 9.4, no mention of life hours and not dimmable. Rmhermen (talk) 11:38, 5 June 2015 (UTC)

Yep, as you say our Philips data does not match the cite. There used to be a 9.4w Lenovation at that cite - impressive low wattage for the lumens, but it does look like it has been discontinued for some more cheaper technology that is no longer so efficient. At one time the 3 LED bulbs we showed in the table represented significantly different levels of LED efficiency/technology, but now they are a commodity we don't see that any more. Should we change to only list one representative LED bulb now, as they are so similar? Rwendland (talk) 20:49, 7 June 2015 (UTC)
I fixed the link to the better Philips bulb in the table- to be to the newer one with better lumens/watt: 8.5w, 800 lumen 10khr bulb. See#Better_lamp and edit history. Doesn't seem like they're so similar to me. --Elvey(tc) 04:35, 9 June 2015 (UTC)

Elvey what is your concern with the addition to the table?Unconventional2 (talk) 13:30, 16 June 2015 (UTC)

What parts of "Not convinced the bulb just added adds to the article." and "Also 810 is wrong; would be 1200 (last row)" and do you miss or not understand?--Elvey(tc) 17:43, 16 June 2015 (UTC)
Sorry I didn’t and still don't see where you wrote "Not convinced the bulb just added adds to the article." Thanks for pointing out the 810/1200 error. What would you see as necessary criteria for the inclusion of additional bulb(s) in the table?Unconventional2 (talk) 18:20, 16 June 2015 (UTC)
As the most energy efficient (lumens/watt) standard consumer bulb I have seen, I believe that as a comparison it shows off the difference between the old and new technology’s the best.Unconventional2 (talk) 18:37, 16 June 2015 (UTC)
.Unconventional2:OK, that's a good enough reason for me to drop my objection. (Though I've had to return (feit) LED bulbs because they were less than half as bright as they claimed to be.) Please learn how to indent your replies. See, e.g. Wikipedia:Tutorial/Talk_pages. --Elvey(tc) 06:48, 17 June 2015 (UTC)
Elvey,Thanks for undoing your change!

Energy price[edit]

The price 13 US cent per kWh seems to be too low for an world wide average. Realistic seems to be something between 10 and 30 Euro cent ~ 12 .. 36 US cent.

I recommend to use at least a value of 20 Euro cent for the table as this makes traditional lamps even more inefficient. Schily (talk) 13:53, 16 June 2015 (UTC)

Much as I'd quite like it, if we went for non-US prices we'd have to find a cite for average bulb prices in Europe somehow as well - it would certainly show LED bulbs further cheaper than the others. But I think that would make it too complicated to do and maintain - we already probably spent too much time maintaing this table. For the U.S. the latest EIA residential average price is 12.35 cents/kWh, so our 13 seems OK. Rwendland (talk) 21:49, 16 June 2015 (UTC)
If table computations in Wikipedia support variables, I would recommend to try to support two sets of prices ac 12.something cent in the US is aprox. 10 Euro cent and this is definitely unrealistic for residential electricity prices in Europe even though the industry may pay something between 3 and 5 Euro cent. But the table already shows that the energy price is dominant for the total costs and I would like to be able to show that with higher energy prices, the total cost difference is much bigger and a LED based lamp typically redeems after a single year already. And BTW: you are right, lamp prices for incandescent and halogen lamps are higher in Europe and LED lamp prices are lower. A noname filament LED lamp with 100 lumen/W and 4W is e.g. available for aprox. 8 Euro - for 10-12 Euro, you get a LED with a CRI > 85. Schily (talk) 10:06, 17 June 2015 (UTC)

Calculation[edit]

As 20 years at 6 hours per day = 43800 hours and as most bulbs don’t last an even multiple of that number I would like to propose that we do a better job of figuring out the last two calculations in the table, by taking the bulb price and mathematically figuring out how much each bulb costs per hour of use and multiplying that by 43800 to arrive at a closer approximation of cost.Unconventional2 (talk) 02:02, 18 June 2015 (UTC)

Updated the “total cost” columns. Using, cost per bulb divided by bulb life times 43800 hours to improve accuracy. Somebody more skilled than I could/should probably update the formula so this doesn’t have to be calculated manually as I did. Also something should be added to the description of the table calculations. I would but am not sure what /how to add it. If/ when I do I will fix that too (if someone else hasn’t already)Unconventional2 (talk) 19:11, 19 June 2015 (UTC)
With this change it is practical to go back to a 10 year comparison period, which is easier for readers to comprehend. We only changed from 10 to 20 years when some LED bulbs had ~20 year lifetimes. We could change to per year, but that would mean adding cents based accuracy, so I don't think this helps comprehension and suggests a spurious level of accuracy. I'll do this unless anyone objects, and also expand the expression so it is easier to maintain. Rwendland (talk) 08:23, 20 June 2015 (UTC)
I have no issue with changing to 10 years. One of the considerations that doesn’t seem to be able to be taken into account on this table is that 20 years from now (even 10 years) electric rates are unlikely to stay at the same as current rates. The longer the time used the more uncertain this gets. Conversely to short a time span doesn’t high-lite the energy savings of LEDs as well. To me 10 years sounds about right but I will defer to others if something better is proposed. Unconventional2 (talk) 23:01, 20 June 2015 (UTC)