Light Bulbs

Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers.

Cartoon of an LED bulb saying 'Watch out world, power saver coming through!' and an incondescent bulb leaving the scene.

If you need a new light bulb, you have a hard decision to make. There are several kinds of light bulbs to choose from. What are they? Does it make a difference?

Lights use a lot of electricity, so it's important to use the most efficient ones. Efficient bulbs use less electricity to make light. Using less electricity in turn creates less pollution. It's better for everyone.

So what are the different kinds of light bulbs?

The most common light bulbs you can find at the store are incandescent, compact fluorescent (CFL), light emitting diodes (LED), fluorescent, and halogen. It can feel overwhelming!

Let's look at each one individually.


incandescent light bulb

Credit: KMJ, alpha masking by Edokter

If you think about a regular light bulb, you're most likely picturing an incandescent bulb. They have the classic tear-drop shape. You can see the little piece of metal inside the glass that creates the light. This is an old design. These bulbs make a lot of heat when they're turned on. That heat is wasted electricity. For that reason, incandescent bulbs aren't very energy efficient.


CFL light bulb

Credit: Sun Ladder

Compact fluorescent bulbs are a newer design. They sometimes are shaped like a coil. These are very energy efficient. They don't create as much heat as incandescent bulbs do. They also last much longer. But CFL bulbs have mercury in them. This is a dangerous element, so CFL bulbs need to be treated with care. You can't throw them in the trash like other bulbs. They need to be recycled. You can take unbroken bulbs to special recycling centers.


fluorescent light bulb

Credit: Christian Taube

Fluorescent lights are the bigger version of CFLs. These are the lights that lots of office buildings and businesses use. They create a lot of light for big areas. Just like CFLs they have mercury in them. They need to be treated with care.


LED light bulb

Credit: Led-neolight

Light emitting diodes are another newer design for lighting. They create a lot of light with very little electricity. They're very energy efficient. And they last a very long time - even longer than a CFL. And unlike CFLs, they don't have mercury. That means they're better for the environment. They don't need to be specially recycled. The only problem is that LEDs are much more expensive than other bulbs. But many people would say they are worth it.


halogen light bulb

Credit: de:Benutzer:Ralf Pfeifer

Some light sockets use halogen bulbs. These work about the same way as incandescent bulbs. They create a lot of heat, but are a little more efficient than incandescent lights. They last for about one year, and they don't contain mercury. These bulbs are usually used for recessed lights like ones set into the ceiling in homes.