Talk:LED lamp

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Neutrality issues[edit]

I know that only relatively recently have affordable LED lamps become available to replace incandescent and compact fluorescent alternatives, yet this article does seem to be biased against the emerging technology, focusing more on aspects such as power factor and colour rather than the pretty indisputable reduction in power consumed per lumen and time to full illumination. Whilst claims about life of an LED lamp are yet to be proved, it is clear that they consume less energy than equally bright alternatives and this article should reflect this. I'm not an expert on these matters, but to me the whole article seems to be biassed against this technology. I will research and improve, but this is a call to arms for those promoting LEDs as a viable and affordable alternative to more conventional lighting solutions.

Out of date?[edit]

I'm no expert about LED lights, and only came to the page to find out, but this sentence seems to have some issues:
"The light output of single LED is less than that of incandescent and compact fluorescent lamps; in most applications multiple LEDs are used to form a lamp, although high-power versions (see below) are becoming available."
- On what measure is LED light output less than incandescent? Surely not on power consumption? On bulb availability? On physical size?
- If "multiple LEDs are used to form a lamp" does that mean "mutliple LED bulbs are used to form an LED lamp"? Maybe it goes back to a previous era of LED spotlights? I can't connect it with the bulbs I've just fitted.
- About "high-power versions (see below) are becoming available", when I see below, illustrations are from 2010 and 2012, which makes me think the article may getting significantly out of date?
Tsuchan (talk) 11:31, 10 March 2016 (UTC)

"By what measure..." By light output per device. Lumens.
Forget the word "bulb" for a moment. A 100 watt incandescent light bulb, for example, has a light output of around 1000 lumens. As far as I know there are no individual LED devices with anything close to that much output that are practical for use as incandescent bulb replacements. Plus there are directionality and cooling issues.. Can you give a link to the LED bulbs you're talking about? Jeh (talk) 12:44, 10 March 2016 (UTC)
Yes, it will always be out of date. Badly so until LED technology plateaus. Here is a 100W equivalent LED bulb for standard UK bayonet fittings. Available as of 4th Sep 2016 - don't know how long the link will be good for. Lithopsian (talk) 10:41, 4 September 2016 (UTC)

Table energy cost calculations are wrong[edit]

The energy cost calculations in the comparison table seem to be on the basis that electricity is charged at fill price on all reactive power. You might say that is a worst case scenario, but I'm not aware of any supplier that uses that method. In practice, a certain proportion of reactive power is completely ignored (typically between a third and a half) and the rest charged at a rate that allows the supplier to recover the implied excess capacity costs (ie not at the full unit rate). Additionally, this is charged on the overall load from a combination of both low and high power factor devices. Domestic services rarely have any reactive power charges at all, and usually small business users aren't charged either. Large commercial users that have overall low power factor loads can correct their power factors at a much lower cost than would be incurred from the utility company. In summary, nobody is paying double for a device with a power factor of 0.5, nobody is paying even close to that, and most people aren't paying anything extra. The table is wrong. I propose adjusting it to a simple basis of real power used - I can't see any other value that would be meaningful of practical. A note could be added that some users may incur a charge if they use too many low power factor devices. Lithopsian (talk) 10:48, 4 September 2016 (UTC)

So I've commented out the whole lot. Commercially available LED lighting simply doesn't have a power factor of 0.5. There seems to be a sort of "climate-sceptic" movement out there out to demonstrate that LEDs are a waste of time and effort, making claims about low power factors and "real costs". In fact, high power LED lighting typically has power factors anything from 0.85 to near 1.0. Cree claims 0.9 for their A-shape domestic bulbs. Various standards authorities mandate power factors over 0.7 for all except the lowest power lamps. A power factor of 0.5 is the worst case for the crudest possible control circuit. The same basic arguments also apply to CFL lamps. In short, I see nothing to justify either the raw power factors in the table or the numbers derived from them. Feel free to expand or add back properly cited data. Lithopsian (talk) 16:15, 4 September 2016 (UTC)

Grammar[edit]

I'm no expert, but the grammar is quite poor in some places. I mostly noticed it in the paragraph regarding "LED drivers". Can somebody clean it up? Pretty Please?