A lot of articles debated the Incandescent vs compact fluorescent vs light-emitting diodes problem, but some issues were not at all covered.
In the image below you will find a scoreboard with all 3 types.
Now lets get everything detailed.
Minimum time before failure (listed in the table in thousands of hours).
Although LEDs and CFLs state very long lifespans compared to the classic bulbs, in practice things are very different.
Here is why:
In the case LED bulbs, indeed, the actual LEDs inside are very unlikely to die, and even if one or more die, tehre are still plenty left, so the light will go on, just at a lower power level.
The problem here is actually the electrical circuit powering them up. The circuit adapts the power imput to 12VDC (because LEDs are usually connected as series of 3).
That circuit can fail much more easy than the actual LEDs. And it does in practice. Power variations can kill it quite easy.
For the CFLs, the big problem is switching (on off cycles). If you let them on permanently, then the lifespan will be clsoe to the specs, but if you keep powering them on and off, you will kill them very very fast (even with just a few consecutive on-offs).
Also, Incandescent bulbs are now produced at low costs with inferior materials and will not have the lifespan they used to have.
It’s clear that it drains more power that the other two, while LEDs are the most energy-efficient.
This is not actually discussed anywhere, and it is very important.
Yes, LEDs are good, but the only problem they have is bad divergence. While a standard incandescent light source will distribute light evenly in all directions, LEDs will have a very focused area of effect.
That means light will not evenly be distributed. In order to prevent this, some LED bulbs use LEDs mounted at an angle or all around a center.
In practice, if the LEDs will be mounted at the same angle, the only rooms that will be well illuminated by them will be the ones that have white walls and reflect a lot the focused light.
So if the general light level in a white-room for LEDs will be on-pair with the other two types, in a room with dark walls it will be a lot lower.
LEDs produce almost no heat, converting most of the electricity into light.
CFLs, while producing sometimes less heat than a normal incandescent bulb, still emit a large amount.
Incandescent bulbs are the only ones that emit natural light, because of they work just like the sun: by incandescence.
As for the actual color temperatures, LEDs can be manufactured in different enough colors, so they can be use for various situations.
CFLs are limited in this and furthermore they emit at a high frequency that has not been proved to be 100% safe for the human eye.
The only type of bulbs that can be used with any power source are the incandescent ones.
LEDs are best used on VDC power source (eliminating the need for the built-in AC-DC circuit) and can have problems when connected directly to AC lines, since some bad power switch configurations will interrupt the null, not the phase, so the LEDs will still have some power and can shine a little while light switch is off.
This problem also exist on CFLs, but manifests itself worse. The CFL will continuously emit light at variable intensity and that will significantly shorten it’s lifespan.
Additionally, CFLs cannot be used with switched that have power-off LED indicators. Current will go through the indicator LED and cause a similar effect.
CFLs contain mercury – they have to, otherwise they wouldn’t work. This might be great for producing light, but it does no good to the environment.
The mercury can accidentally be released in vapor form endangering anything alive who inhales it.
While CFLs and incandescent bulbs can break and cause physical damage, LED bulb casings are usually made of plastic so there is no danger from them.
But then, LEDs contain circuits that can actually cause a fire if malfunctioning. The chance is very small, but exists.
LEDs can be manufactured in a wide and variable form which means that you can have any shape /spatial distribution, variable density (therefore size).
This is a big advantage.
Incandescent bulbs can also be much smaller that default size.
But CFLs present a problem, because they cannot be technically manufactured in very small sizes.
The verdict is now complete, LEDs win, as long as the conditions of powering them are met while divergence and environment reflexions are proper. When one or more conditions are not met, incandescent bulbs remain the only viable solution.
CFLs should be removed from circulation world-wide. Unless suddenly wireless power systems become unlocked for the general market, they serve no use.