How would you assess the led can save energy or not?

LED is light emitting diode, the electricity energy can be transformed into visiable light by the led.but the emission of light that does not derive energy from the temperature of the emitting body. and traditional light from the thermal radiation,just like:incandescent and halogen lamps.so different light source has different lighting effects.
the lighting effects was measured by luminous flux and input power. this unit is 1m/w.

for example, the simple light device:ther are has 3*14W grille lamp.when it tries to use the 14W/1200lm lamp tube,
Also equipped with 2 pcs 14W ballasts. We worked out the system power as 18+32.5=50.5W , grille effects(LOR) as 70%.
so the light effects as 3600*70%/50.5W＝49.9lm/W .

if substitute the grille effects and substituted was slightly higher than in the 49.9lm/W . we can say that the substituted is energy-saving.