One of the key advantages of LED-based lighting is its high efficiency, as measured by its light output per unit power input. White LEDs quickly matched and overtook the efficiency of standard incandescent lighting systems. In 2002, Lumileds made five-watt LEDs available with a luminous efficacy of 18–22 lumens per watt [lm/W]. For comparison, a conventional 60–100 W incandescent lightbulb produces around 15 lm/W,
so another word…it’s approx 12 to 20 times more efficent than incandescent lights…
The last time I check…LEDs are the most energy efficent light emiting device (More efficent than fluorescent lights)
Under “law of conservation of energy”
Energy does not disappears
In most lighting device powered by electricity.
Electricity is converted to both HEAT and LIGHT
So TOTAL electricity input = HEAT output + LIGHT output
Base on that principle. Whichever device is coolest to touch is most energy efficient, that’s a no brainier and no need to see “energy-star” compliant logo to tell you that.
I am an engineer so I know…