In the past decade, “green” energy and energy efficiency have become one of the most talked about technology trends. To some, it is a concern about impact on the environment, to others it is a way to cut energy costs. One of the darlings of energy saving technologies have been LEDs and for good reasons. They run cooler than incandescent lights, rival or even beat fluorescent lights in efficiency and can be designed into many space-constrained applications with ease. As a result, LEDs can be found in anything from a blinking light on a remote control, to a flash on camera phone, a light source in a flashlight or headlights on a supercar.
With the prices on LEDs continuously going down, manufacturers push them into more and more application at prices competitive with technologies they are replacing. Sometimes this push for “everything LED” goes a bit far and results in products that are not very useful or even inferior to the “old” technologies they are replacing.
Exhibit A: 100(!) LED flashlight versus 1 LED flashlight. Now we all like to have more of stuff: more salary, more helpings at dinner, and more vacation days. So more LEDs should clearly be better than less LEDs, let alone just one, right? Well, it certainly depends on whether you like to shine the light beyond 10 feet or carry it in a pocket. With 100 small LEDs in a flashlight with no optics, what you get is a flood light that lets you see your feet very well and not much beyond that. If your aim at night is to see the rabid dog before its chewing on your leg, a single LED light with good optics will be a considerably better choice as it will easily have a throw of 100 feet or more. The only saving grace for 100 LED flashlight is that it serves as a good weapon to fight off that rabid dog.
Exhibit B: Cheap LED car light bulb versus halogen light bulb. Pictured are 9005 lights bulbs, an LED based one and a regular halogen bulb. Both fit the same socket and are intended for use as Day Light Running (DLR) lamps or fog lights. This is where their similarities end. A regular halogen light bulb can be approximated with a point light source and the reflectors of car headlights are optimized for it. With the LED bulb, there are numerous directional light sources that are not optimized for the existing reflector design and lead to scattered light and glare for oncoming traffic. Beyond that, even 19 surface mounted LEDs with little to no heat sinking cannot compete in light output with a halogen light bulb. The end result of replacing a halogen light with cheap LED light is less light where a good chunk of it is wasted on useless glare.
So, lesson for the day? If you want your LED fix with the most light output, get the Audi R8 with LED headlight option, it’s only $10,000! On top of the actual price of the car.
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