Buying a light bulb used to be easy

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Buying a light bulb used to be really easy, but that changed with the arrival of energy-saving models.

It is very hard to buy a quality light bulb. I have often bought from "good" brand-names and got disappointed.

Here is a feature list:

  • Brightness.
    Unfortunately, the lumen values are not linear (they do not increase proportional to the current flow), especially from 2,000 Lumen. I don't know the maths. If you can help, please drop me a line. This is the table I have been using for reference:
Incasdencent Watt Lumen LED Watt Energy-saver Watt Halogen Watt Info source
40 W 450 lm 5 W 10 W 1
60 W 800 lm 10 W 15 W 1
75 W 1100 lm 14 W 20 W 1
100 W 1,200 lm
150 W 1,700 lm
1,900 lm 23 W
2,700 lm 28 W
2,800 lm 30 W
3,000-3,250 lm 160 W
200 W 10,000 lm

Info source 1: El País, La (ardua) tarea de elegir la bombilla perfecta y ahorrar.

  • Color temperature.
    2700K is best, it yields a yellowish light comparable to the traditional incasdencent light bulbs with a tungsten (wolfram) filament.
    3000K might be described as "soft, warm white", but it's a little too cold and you'll notice the difference. Anything over 3000K will be too cold, and the light will turn blueish.
  • Turn-on speed.
  • Lifespan.
  • Cycling endurance.
  • Clear or frosted glass.
  • Noise.
  • Dimmable.
  • Physical robustness.
  • Operating temperature.

Compact fluorescent lamp (CFL)

I am particulary dissatisfied with compact fluorescent lamp (CFL) technology, especially after all the hype.

Its many drawbacks are:

  • Expensive.
  • Slow to turn on.
  • Often last much shorter als advertised, due to low cycling endurance.
  • Noisy. Most CFLs make a humming noise that you may notice in a quiet environment.
  • Cold light colour.
  • Normally not dimmable.
  • The light bulb itself is also ugly.
  • Contain toxic mercury (quicksilver) which complicates their disposal.
  • They turn darker with time.

On the bright side, they consume very little electricity.

LED lamp

LED lamps have a few drawbacks:

  • Expensive.
  • Weak. I just cannot find powerful LED lamps. The ones I see around are too weak for the living room.

They win in every other category.

Halogen lamps


  • Cheap.
  • Fast to turn on.
  • Bright.


  • High electricity consumption compared to CFLs or LEDs.
  • They lose a lot of brightness with age (see 'cooking' below).
  • Dimmable, but you often get a hummy noise when dimmed from the power supply.
  • They get very hot, so:
    • They tend to turn darker (they 'cook') with time.
    • If you touch one during operation, you'll get burnt.
    • Careful when cold too. Fingertip oil may make them even hotter and damage them.
  • Some halogen bulbs shed a cold light (colour temp 3000 K or higher).

Fluorescent tubes


  • Cheap.
  • Powerful.
  • Consume little electricity.


  • Big, long.
  • The starters break down often.
  • Cold colour.
  • Slow to turn on.
  • Poor cycling endurance.
  • Humming noise.
  • Not dimmable.
  • Brittle.