PREDICTING the biggest flash developments that'll hit in 2019.....

Enderman · December 9, 2018, 11:25pm

mattheww1950:

The best High Pressure Sodium (HPS) lamps can deliver right around 100 lumens per watt, which at this point is only marginally lower efficiency then the best LED’s. Low Pressure Sodium is another matter entirely. If you can stand the color, because it is basically a monochromatic yellow, LPS can delivery over 200 lumens per watt in some lamps. There is however a significant difference in lifetime however, and LED’s are generally longer lived than HPS. The real question however is what is the longevity of the supporting electronics for the LED, and I suspect much of it will come up well short of the LED life expectancy. Generally HID ballast have very long life. There aren’t any active components in them, so if well designed, 20-30 years is not unrealistic. The problem with Electronics is that once you get past about 10 years, repairs become a real challenge because the parts they were built with no longer exist!

Go take a look at the lumens/watt numbers and maybe you will realize that 100lm/W is not “marginally lower than the best LEDs”