Light Bulb Tutorial

Have you gone shopping for light bulbs lately?  There are so many different options now, it’s almost mind boggling.  There is a lot of information to digest about each of the different type bulbs, but the first thing most people want to know is how much light each type will produce.  Over the years most of us have used the word “watt” as a measure of brightness.  For instance, we might want a 75 watt bulb in a lamp next to the chair where we read.  But “watt” is really a measure of the amount of power consumed by the bulb while it converts electricity to light.  The amount of light, or brightness, of the bulb is actually measured in lumens.  Although bulbs from different manufacturers vary in the amount of light produced while consuming a specific number of watts, the table below uses average watts and lumens to compare the most common bulbs you might find.

Although standard incandescent bulbs have been around since the end of the 19th century, their days are numbered.  While you’ll still see some on store shelves, manufacture of 100 watt incandescents ended in 2012, and 75 watt versions ended in 2013.  January 1, 2014 marked the end of manufacturing of 60 watt and 45 watt bulbs.  Retailers may continue selling standard incandescent bulbs until their inventory is gone.

Compact fluorescent lamps (CFL) are a good alternative to the disappearing incandescent bulbs, but there are some things to consider  before choosing a CFL.  One of the first things you may want to consider is the color of the light they produce.  First generation CFL bulbs produced a very bright white light, which many people didn’t like because they were accustomed to the warmer color of light from inacandescents.  The color of light is measured on the Kelvin Color Temperature Scale, and ranges from approximately 1700K (a match flame) to 27,000K (a clear blue sky).  The light produced by various bulbs generally falls in the color range of 2700K – 6500K.  Standard incandescent bulbs produce light in the color temperature of approximately 2700K.   Light from the earliest CFL bulbs was approximately 5000K.  But now, you can also find CFLs in the 3000K range if you prefer that warmer color.  You should also consider how the CFL will be used; many CFLs won’t work with a dimmer.  Cold weather may also impact them – many flicker or take a long time to reach full brightness in a cold environment, or they may not work at all.  There is a safety consideration, too:  CFL bulbs contain a small amount of mercury, so caution should be used if they break.  The mercury also means that CFLs must be disposed of as hazardous waste.

Light emitting diode (LED) bulbs use approximately 95% less power than incandescent bulbs to produce the same amount of light and last much longer.  They are available in the warm color range and most work well with dimmers.  Also, cold weather doesn’t have any effect on LEDs.  Like CFLs, LEDs cost more than standard incandescent bulbs, but they have a much long life expectancy.  LEDs are available in various color temperatures, ranging from warm to bright.

Another possible alternative to standard incandescent bulbs is the halogen bulb.  It is an incandescent-type bulb with halogen gas inside to slow the burn of the filament.  These bulbs are approximately 40% more efficient than a standard incandescent and have a long life, but they operate at a hotter temperature, so they may be a safety issue for some applications.  Halogen bulbs produce a warm light, approximately 3000K.

If you decide to replace your incandescent bulbs with Energy Star CFL or LED bulbs, they may be eligible for a rebate.  Check out the rebates page to see if yours qualify and to download the Rebate Forms.

Light Bulb Comparison

Use our Electric Cost Calculator to help you decide how much it will cost you to operate various bulbs.

For more information, check out our Right Light Guide.