by WatchfulEye » Tue 09 Oct 2007, 20:43:03
This is interesting news, and really demonstrates that public sentiment is beginning to change.
LEDs have improved immensely in recent years, but still aren't ready for the primetime, I don't think. Warm white LEDs are now available, which give a much more pleasant white than the very blue cast that standard 'white' LEDs produce. However, one thing that LED really struggles with is colour quality - they are much, much worse than CFL, and although the warm white are better, colour accuracy is not a match for CFL.
The other problem with LEDs is variability - LED production is inherently a variable process, so you get a wide spectrum of colours, brightness levels and hues. This is quite obvious on the cheaper lamps as each individual LED is a different brightness and colour to its neighbours. More expensive lights may use carefully matched LEDs in one lamp fitting, but not necessarily be matched from one fitting to another.
Even LED efficiency is nothing to write home about today. LEDs that you can buy today are almost as good as CFLs, although prototypes have been demonstrated with significantly better efficiency.
My personal preference for lighting is conventional tube fluorescent. If you can get them, the modern 5/8" diameter tubes really are good (but haven't filtered down to the consumer mass market, they are 'professional' products, with professional performance but a professional price tag). Modern fluorescents are highly efficient (approx 105 lumens / Watt, compared to CFL which are about 60 lm/W), start quickly (approx 1 second), start at full brightness (no warm up time), have zero flicker, zero buzz/hum, accurately controlled colour variability and very good colour rendering, as well as producing a relatively glare free light due to the long shape.
Not only are conventional fluorescent more efficient than compact, but they also contain less mercury (CFLs are medium pressure lamps, so need a relatively large mercury charge and high temperature to generate the appropriate pressure) and last twice as long (15k hours for modern lamps).
If you do have rooms to light, and fluorescents would be appropriate - then they can be good. But you have to make sure you get modern tubes/fittings (electronic fittings and 'triphosphor' tubes), the cheapo ones on the mass market use the old 1950s technology, with 1950s performance (flicker, green skin syndrome, annoying flickering when bulbs burn out, etc.)