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> A high pressure sodium vapor lamp has an efficiency of around 150 lm/W Source? Allegedly, Cree has developed a white LED with up to 254 lm/W. [1] [1] Cree

• ars 13y ago
  > Source? It's poor form to ask for a source of something that would take you 15 seconds to google. > Allegedly, Cree has developed a white LED with up to 254 lm/W Interesting considering that the theoretical maximum is 251 lm/W - so I wonder which law of physics they violated to do that. (Most likely it's not actually white, but reddish.) And this time I will give you a source since this is a tiny bit harder to google http://physics.ucsd.edu/~tmurphy/papers/lumens-per-watt.pdf http://physics.ucsd.edu/~tmurphy/papers/lumens-per-watt.pdf