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> The best LEDs are now remarkably close to the theoretical maximum luminous efficacy. Do you have any pointers/references where I could read up on this? I'm d
by jwr 10y ago
> The best LEDs are now remarkably close to the theoretical maximum luminous efficacy.
Do you have any pointers/references where I could read up on this? I'm designing home lighting with power leds and finding that despite all the hype, it's quite difficult to beat the efficiency of TL5 HE fluorescent tubes with LEDs. I also noticed that while the output in lm/W has been increasing, it seems to increase very slowly these last few years.
- jdietrich 10y agoDepending on acceptable bandpass and desired color temperature, a white light has a maximum luminous efficacy of 250–370 lm/W. Nichia currently offer a white LED that achieves 210 lm/W at >80 CRI. Cree have high-flux LEDs capable of ~200 lm/W at >70 CRI. There's room for improvement, but nothing revolutionary. Cree had a prototype device achieving 303 lm/W in 2014, but it isn't currently commercially viable. Lower efficiency LEDs still make up a large proportion of the market for simple reasons of cost. https://arxiv.org/pdf/1309.7039.pdf https://arxiv.org/pdf/1309.7039.pdf https://www.nichia.co.jp/specification/products/led/NF2W757G-F1-E.pdf https://www.nichia.co.jp/specification/products/led/NF2W757G... http://www.cree.com/~/media/Files/Cree/LED%20Components%20and%20Modules/XLamp/Data%20and%20Binning/ds%20XPL.pdf http://www.cree.com/~/media/Files/Cree/LED%20Components%20an... http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier http://www.cree.com/News-and-Events/Cree-News/Press-Releases...
- jwr 10y agoThank you — this is much-appreciated information and interesting reading.