There are several types of light bulbs to choose from and some are inevitably better than others. In general, our main concern is to be able to save as much energy as possible. But there are also other factors that could influence our decision. For example:

The luminous efficiency of a light bulb.

Most people prefer light bulbs that are more luminous and they often prefer to pay more but to also have more light. Light is measures in units called lumens and they correspond to the amount of light that is produced per watt. Of course, no source of light available today is 100% efficient. Fluorescent light bulbs are the most luminous efficient and they only offer between 9% and 11%. Incandescent light bulbs stand between 1.9% and 2.6%. So CFL bulbs are the most efficient in this case and they are followed by halogen bulbs and incandescent bulbs.

Halogen vs. incandescent.

Here’s an interesting question: what’s the difference between a halogen bulb and an incandescent one. Well, it’s simple. Incandescent bulbs produce light by heating a filament of tungsten metal until it is white hot. In the case of normal light bulbs, the tungsten slowly vaporizes and deposits on the inside of the bulb. At one point, it becomes too thin to carry an electric current and the bulb burns out. But in the case of halogen bulbs, the special gas found inside causes the vaporized tungsten to deposit back onto the filament. It’s why halogen bulbs last longer and burn hotter.

Climate-controlled efficiency.

Some types of light bulbs are more efficient in certain climates. For example, fluorescent lamps are more efficient in warm climates. That’s because incandescent bulbs emit a lot of heat and they are suitable for these areas. This makes them particularly suitable for cold climates where switching to CFLs would only increase the energy cost and greenhouse gas emission.

The new halogen bulbs.

Graphic by George Retseck and Jen Christiansen

Halogen bulbs are not all the same. In fact, a new class has been developed. These particular bulbs use a special infrared coating to redirect infrared light back towards the filament. This way waste heat is reduced and efficiency is improved with up to 30% compared to the usual incandescent light bulb. However, these halogen bulbs are still not as energy-efficient as CFLs but they still offer a wonderful alternative for those that prefer halogen bulbs and would rather not switch to a different type.