This doesn't make any sense.
A high pressure sodium vapor lamp has an efficiency of around 150 lm/W. An LED has an efficiency of under 100 lm/W.
Where is the energy savings? If anything an LED uses more energy, not less.
A high pressure sodium vapor lamp has an efficiency of around 150 lm/W. An LED has an efficiency of under 100 lm/W.
Where is the energy savings? If anything an LED uses more energy, not less.
Also, the referenced document shows LED lights as emitting 70 - 150 lm/W, so power consumption may be better than you think.
[1] http://www.grahlighting.eu/en/street-lighting-technology-com...
Source?
Allegedly, Cree has developed a white LED with up to 254 lm/W. [1]
[1] Cree Sets New Record for White LED Efficiency http://techon.nikkeibp.co.jp/english/NEWS_EN/20120423/214494...
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