Light Emitting Diode (LED) and Compact Fluorescent Lights (CFL) bulbs have revolutionized energy-efficient lighting.
CFLs are simply miniature versions of full-sized fluorescents. They screw into standard lamp sockets, and give off light that looks similar to the common incandescent bulbs— not like the fluorescent lighting we associate with factories and schools.
LEDs are small, very efficient solid bulbs. New LED bulbs are grouped in clusters with diffuser lenses, which have broadened the applications for LED use in the home. LED technology is advancing rapidly, with many new bulb styles available. Initially more expensive than CFLs, LEDs now bring more value since they last longer.
The Status of Energy Efficient Lighting
With a burgeoning supply of far more efficient light bulb options, the EU began a phased ban of incandescents in 2009. Canada followed suit banning the manufacture and import of higher wattage incandescent bulbs beginning in 2014.
In 2007, the U.S. set new energy efficiency guidelines for all bulbs, which effectively phased out the least efficient incandescent bulbs. Incandescents are now available only if they meet the new energy standard.
According to the US Department of energy, rapid adoption of LED bulbs would save hundreds of millions of tons of greenhouse gases from entering the atmosphere.
Australia, China, and numerous countries in Asia and Latin America have likewise phased out or banned incandescent bulbs. These changes are estimated to save each country that switches to energy efficient bulbs millions of dollars annually.
According to the US Department of energy, rapid adoption of LED bulbs would collectively save $265 billion over the next 20 years. This switch would also help eliminate the need to build 40 new power plants and save hundreds of millions of tons of greenhouse gases from entering the atmosphere.
LED Light Bulbs
LEDs (Light Emitting Diodes) are solid light bulbs that are extremely energy-efficient. When first developed, LEDs were limited to single-bulb use in applications such as instrument panels, electronics, pen lights and, more recently, strings of indoor and outdoor Christmas lights.
Manufacturers have expanded the application of LEDs by “clustering” the small bulbs. The first clustered bulbs were used for battery-powered items such as flashlights and headlamps. Today, LED bulbs are made using as many as 180 bulbs per cluster, and encased in diffuser lenses, which spread the light in wider beams. Now available with standard bases that fit common household light fixtures, LEDs are the next generation in home lighting.
A significant feature of LEDs is that the light is directional, as opposed to incandescent bulbs, which spread the light more spherically. This is an advantage with recessed lighting or under-cabinet lighting, but it is a disadvantage for table lamps. New LED bulb designs address this directional limitation by using diffuser lenses and reflectors to disperse the light more like an incandescent bulb.
The high cost of producing LEDs has been a roadblock to widespread use. However, researchers at Purdue University have developed a process for using inexpensive silicon wafers to replace the expensive sapphire-based technology. This has rapidly brought LEDs into competitive pricing with CFLs and incandescent bulbs. LED bulbs are now the standard for most lighting needs.
Benefits of LED Lightbulbs
LED bulbs last up to 10 times longer than compact fluorescents, and 40 times longer than typical incandescent bulbs.
Since LEDs do not have a filament, they are not damaged under circumstances when a regular incandescent bulb would be broken. Because they are solid, LED bulbs hold up well to jarring and bumping.
These bulbs do not cause heat build-up; LEDs produce 3.4 btu’s/hour, compared to 85 for incandescent bulbs. Common incandescent bulbs get hot and contribute to heat build-up in a room. LEDs prevent this heat build-up, thereby helping to reduce air conditioning costs in the home.
No mercury is used in the manufacturing of LEDs.
LED light bulbs use only 2-17 watts of electricity (1/3rd to 1/30th of Incandescent or CFL). LED bulbs used in fixtures inside the home save electricity, remain cool, and save money on replacement costs since LED bulbs last so long. Small LED flashlight bulbs will extend battery life 10 to 15 times longer than incandescent bulbs.
The cost of new LED bulbs has gone down considerably in the last few years and is continuing to go down. To see a cost comparison between the different types of energy saving light bulbs, see our Light Bulb Comparison Charts.
Light for Remote Areas and Portable Generators
Because of the low power requirement for LEDs, using solar panels becomes more practical and less expensive than running an electric line or using a generator for lighting in remote or off-grid areas. LED light bulbs are also ideal for use with small portable generators which homeowners use for backup power in emergencies.
Choosing an LED Light Bulb
Many different models and styles of LED bulbs are emerging in today’s marketplace. When choosing a bulb, keep in mind the following:
Estimate Desired Brightness
Read the package to choose desired brightness level. You can use wattage to compare bulb illumination. For example, a 9 watt (W) LED is equivalent in output to a 45 W incandescent. However, wattage measures energy used, not the light output. The new method for comparing bulbs is lumens. ‘Lumens’ is the measure of perceived brightness, and the higher the lumens, the brighter the bulb. Bulbs with similar wattage may vary in lumens. The FTC has mandated that all light bulb packages display lumens as the primary measure for comparing bulbs. For more information about lumens, see LED Terminology further down this page.
Do You Need a 3-Way Bulb?
New LED bulbs are available as combination three-way bulbs. These replace 30, 60 and 75-watt incandescent bulbs, while consuming 80% less power than an incandescent bulb.
Choose Between Warm and Cool Light
New LED bulbs are available in ‘cool’ white light, which is ideal for task lighting, and ‘warm’ light commonly used for accent or small area lighting.
Standard Base or Pin Base
LEDs are available in several types of ‘pin’ sockets or the standard “screw”(Edison) bases for recessed or track lighting.
Choose Between Standard and Dimmable Bulbs
Some LED bulbs are now available as dimmable bulbs. They will work with any standard dimmer switch.
Choose High Quality Bulbs or They Will Die Prematurely
Don’t buy cheap bulbs from eBay or discounters. They are inexpensive because the bulbs use a low-quality chip, which fails easily. Many cheaper varieties also don’t work inside enclosed light fixtures (see below) and will burn out within a year or less as they heat up.
Enclosed Light Fixtures Require Special LED Bulbs
LEDs have mechanisms to dissipate heat build-up, but these require more airflow than many common light fixtures permit. Bulbs designed for enclosed fixtures will last longer than standard LEDs. Look for explicit statements saying that a bulb works inside enclosed light fixtures.
Recessed, ‘Pot’ and Can Light Fixtures
Be sure to check the diameter of the bulb you’re considering against that of the can you’re filling. Your existing bulbs should say whether they are R20, BR30, or BR40. Look for these same numbers on the LEDs you’re purchasing. Because heat can also be an issue with recessed lighting, look for a description that indicates its suitability for recessed fixtures.
Floodlights, Spotlights, and Accent Lighting
If you’re replacing floodlights, spotlights, or accent lighting, be sure to consider whether you want the light to be diffused or focused. Omnidirectional bulbs will cast light over a wide area, while spotlights and floodlights will have a narrower band of illumination.
Common Styles of LED Bulbs
Diffused or Omnidirectional Bulbs
In this style LED bulb, clusters of LEDs are covered by a dimpled lens which spreads the light out over a wider area. Available in standard Edison bases, these bulbs have many uses, such as area lighting for rooms, porches, reading lamps, accent lamps, hallways and low-light applications where lights remain on for extended periods.
Dimmable Globe LED Bulbs
Designed for bathroom vanities or anywhere a globe bulb is required, these bulbs produce light equivalent to a 40-watt incandescent bulb, yet only consume 10 watts of power. Dimmable from 100% to 10%, these bulbs have a 200 degree beam angle to cast light in a wide area.
Track Lighting, Pin Base
Available in MR-16 (pin base), LEDs are ideal for track lighting. LEDs do not contribute to heat build up in a room because no matter how long they remain on, they do not get hot to the touch. Also, because they are 90% more efficient than incandescent bulbs, and last 10 times longer than CFLs, the frequency of changing bulbs is greatly reduced.
Flood Reflector LEDs for Recessed Cans and Track Lights, Screw-In Base
LEDs are now available for standard recessed lighting pots and housings. They range from 7.5 to 17watts, with beam widths from PAR20 to PAR38. Several models are dimmable. Also, because they are 90% more efficient than incandescent bulbs and last 10 times longer than CFLs, the frequency of changing bulbs is greatly reduced.
Flame Tip, Candelabra Base LEDs
Designed to replace incandescent candelabra bulbs, these flame tip LEDs deliver the equivalent light of a 25 – 35 watt incandescent while only drawing 3.5 watts of electricity. Because of the heat sink in the base, light doesn’t disperse downwards as much as a typical incandescent candelabra bulb.
LED Tube Lights
Designed to replace fluorescent tube bulbs, these LED tubes are available in 8 and 16 watts, which replace traditional 25-watt and 40-watt T8/T10/T12 fluorescent tubes. Because fluorescent lights are often installed in high ceilings in commercial sites, there are additional savings because the frequency of changing bulbs is greatly reduced.
LED panel lights come in a variety of sizes and can replace overhead tube lighting in both commercial and residential applications.
LED String Lights
Most commonly used for the winter holidays, replacing a string of incandescent holiday lights with LEDs can cut holiday lighting costs by more than 95%! Plus they can last for decades, making them an even more budget-friendly choice. For more information about energy efficient holiday lighting read our article: LED Christmas Lights and Other Energy Efficient Decorations
Coloring Rendering Index (CRI)
CRI represents the quality of light and its faithfulness to render colors correctly, that is, to enable us to perceive colors as we know them. The ideal CRI is 100, and some incandescent bulbs approach this level. LEDs and CFLs use different design components in trying to equal the CRI of incandescent bulbs. LED bulbs CRI ratings range from 70 to 95, and the best CFLs have ratings in the mid 80s. The LED CREE CR6 bulb, for example, features a CRI of 90 Warm White making it one of the highest in the industry.
Correlated Color Temperature (CCT)
CCT is the measure used to describe the relative color appearance of a white light source. CCT indicates whether a light source appears more yellow/gold/orange or more blue, in terms of the range of available shades of “white.” CCT is given in kelvins (unit of absolute temperature). 2700K is “warm” and 5000K is “cool.” The typical light color we are used to in indoor home lighting is “warm,” 2700 – 2800K.
When buying a light bulb, look for bulbs that produce more light but consume less energy.
A unit of standard measurement that is used to describe the amount of light contained in an area as perceived by the human eye. The more lumens, the brighter the light. You can use lumens to compare the brightness of any bulb, regardless of the technology behind it, and regardless of whether it’s incandescent, CFL or LED.
The flow of light measured in lumens. With light bulbs, it provides an estimate of the apparent amount of light the bulb will produce. Depending on the application, much of an incandescent bulb’s light is wasted because it’s emitted in every direction. LED bulbs, on the other hand, put out directional light, sending all of the light exactly where it’s needed.
In practical application, when buying a light bulb, look for bulbs that produce more light but consume less energy. Understanding lumens as a measure of brightness makes it easier to select the most efficient bulb for your application.
LED Bulb Colors
Most LED bulbs used today are clear or white bulbs, commonly available in ‘cool’ or ‘warm’ white light. But LEDs are also available in colors and used as individual bulbs, or in clusters, for special applications.
Red is the traditional color for maintaining night vision. Some LED headlamps and flashlights have the option of switching to red light for use at night.
Green is now the preferred light color for pilots and the military. The green color is also great for retaining night vision, and it doesn’t erase or render invisible the red markings on maps and charts.
Many people like blue light because it feels easy on the eyes, but research indicates that some lights in the blue spectrum can affect human circadian rhythms and therefore, sleep. Scientists now recommend against using objects lit with blue light 2-3 hours before bedtime.
The most popular of the LED colors. It produces a soft white light, without harsh reflection, glare or shadows.
LED amber bulbs do not attract flying insects like ordinary white bulbs. Amber LEDs are used outdoors in areas such as patios and decks where insects flying around lights are a nuisance.
Lumen Output Comparison: LED vs CFL vs Incandescent
Did you know that watts don’t tell you how bright a light will be?
To compare different light bulbs, you need to know about lumens. Lumens, not watts, tell you how bright a light bulb is, no matter the type of bulb. The more lumens, the brighter the light. Beginning in 2012, labels on the front of light bulb packages now state a bulb’s brightness in lumens, instead of the bulb’s energy usage in watts.
While lumens are the best measurement of comparative lighting among the various bulbs, they are not always a perfect measure. Some floodlights use an internal reflector in the bulb to send the light facing downward. When shopping for light bulbs, note that bulbs equipped with reflectors will deliver increased directional light.
The chart below shows the amount of brightness in lumens you can expect from different wattage light bulbs. The LED bulbs require much less wattage than the CFL or Incandescent light bulbs, which is why LED bulbs are more energy-efficient and long lasting than the other types of bulb.
|Incandescent Watts||Lumens||CFL equivalent||LED equivalent|
Handling and Disposal of LED Bulbs
LEDs can contain small amounts of heavy metals like lead, arsenic, and nickel, so it’s best to handle with care. Treat any broken bulb as hazardous waste, which means wearing gloves and a mask and cleaning the area thoroughly. Double bag the bulb fragments and any cleaning tools used and contact your local hazardous waste site for instructions on their preferred method of disposal. Many will likely have you simply throw it in the trash, while others will ask that you bring it to the hazardous waste collection site.
While LEDs are recyclable, recycling programs are few and far between. Call your local recycling collection center to find out if LED bulb recycling is available in your area. You can also try searching at Recycle Nation for a recycling facility that accepts LED bulbs near you.
CFL Lighting Benefits
CFLs are four times more efficient and last up to 10 times longer than incandescents. A 22 watt CFL has about the same light output as a 100 watt incandescent. CFLs use 50 – 80% less energy than incandescents.
Although initially more expensive, you save money in the long run because CFLs use 1/3 the electricity and last up to 10 times as long as incandescents. A single 18 watt CFL used in place of a 75 watt incandescent will save about 570 kWh over its lifetime. At 8 cents per kWh, that equates to a $45 savings.
Reduces Air and Water Pollution
Replacing a single incandescent bulb with a CFL will keep a half-ton of CO2 out of the atmosphere over the life of the bulb. If everyone in the U.S. used energy-efficient lighting, we could retire 90 average size power plants. Saving electricity reduces CO2 emissions, sulfur oxide and high-level nuclear waste.
Newer CFLs give a warm, inviting light instead of the “cool white” light of older fluorescents. They use rare earth phosphors for excellent color and warmth. New electronically ballasted CFLs don’t flicker or hum.
CFLs can be applied nearly anywhere that incandescent lights are used. Energy-efficient CFLs can be used in recessed fixtures, table lamps, track lighting, ceiling fixtures and porch lights. Three-way CFLs are also now available for lamps with 3-way settings. Dimmable CFLs are also available for lights using a dimmer switch.
Choosing a CFL
CFLs come in many shapes and sizes. When purchasing CFLs, consult the seller for recommendations and consider the following:
Choose Your Preferred Light Quality
CFL bulbs have a Kelvin or ‘K’ number listed on the packaging. CFLs with K numbers between 2700-3000 give off a soft bright light like incandescents. CFLs with K numbers between 3500-6000 give off a bright light. As you go up the K number scale the light gets bluish and closer to daylight.
Approx. 2700K = Warm White (looks just like incandescent)
Approx. 5000K = Cool White (white/blue, bright light)
Choose the Shape
CFLs are available in a variety of shapes to fit a range of lamps and lighting fixtures. See below on this page for the most popular CFL shapes.
Match Lumens to the Incandescent Being Replaced
Lumens indicate the amount of light being generated. (Wattage is a measure of energy use, not light strength.) Lumen output is printed on the bulb package or on the bulb product page if purchasing bulbs online.
CFL Light Bulb Models
CFLs are available in a variety of styles or shapes. Some have two, four, or six tubes. Older models, and specialty models, have separate tubes and ballasts. Some CFLs have the tubes and ballast permanently connected. This allows you to change the tubes without changing the ballast. Others have circular or spiral-shaped tubes. In general, the size or total surface area of the tube determines how much light the bulb produces.
The following CFL bulb models come with standard sockets for easy installation in most common household applications.
These bulbs are designed as a continuous tube in a spiral shape which has similar outside shape and light casting qualities to a standard incandescent bulb. Spiral CFL bulbs are made in several sizes to fit most common fixtures.
Triple Tube Lamps
These CFLs have more tubing in a smaller area, which generates even more light in a shorter bulb. They pack high light output into a very small space and can be used in fixtures designed for incandescent bulbs, such as table lamps, reading lamps, open hanging lamps, and bare bulb applications.
These are regular CFL spiral lamps which are placed inside a dome cover and fitted with a standard base which fits common lamp sockets. They are designed to give the appearance of the traditional light bulb for consumers looking for the more familiar light bulb appearance. The glass diffuser provides a quality of light similar to the ‘soft-white’ type of incandescent bulbs.
This shape is commonly used in bathroom vanity mirrors or open hanging lamps, and bare bulb applications. Bathroom vanities usually require multiple bulbs, which generate radiant heat. The CFL globe will reduce this heat buildup while saving energy. The glass diffuser provides a soft-white light.
These lamps are designed to be ideal for recessed and track lighting fixtures, indoors and outdoors. They provide diffused, soft, white light, and generate less heat than will an incandescent flood or a halogen bulb. CFL flood lamps are available in varying sizes and wattages.
The screw-in torpedo-shape and the small-base of this bulb is designed for smaller light fixtures throughout the house, from chandeliers to sconces. To use a smaller candelabra-based bulb in a regular socket, you can use a socket reducer.
Limitations of CFL Lightbulbs
Although CFLs are an excellent source of energy-efficient lighting, they are not always the best choice for all lighting applications. Here are a few limitations to consider:
- On/Off Cycling: CFLs are sensitive to frequent on/off cycling. Their rated lifetimes of 10,000 hours are reduced in applications where the light is switched on and off very often. Closets and other places where lights are needed for brief illumination should use incandescent or LED bulbs.
- Dimmers: Dimmable CFLs are available for lights using a dimmer switch, but check the package; not all CFLs can be used on dimmer switches. Using a regular CFL with a dimmer can shorten the bulb life span.
- Outdoors: CFLs can be used outdoors, but should be covered or shaded from the elements. Low temperatures may reduce light levels – check the package label to see if the bulb is suited for outdoor use.
- Temperature: As noted above, low temperatures usually reduce light levels in CFLs temporarily because it takes them some time to heat up to their full capacity. For this reason, most CFLs aren’t the best choice for cold basements or outdoor walkways in northern climates.
- Retail Lighting: CFLs are not spotlights. Retail store display lighting usually requires narrow focus beams for stronger spot lighting. CFLs are better for area lighting.
- Mercury Content: CFLs contain small amounts of mercury, which is a toxic metal. This metal may be released if the bulb is broken or during disposal. For more information about mercury and CFLs, see below.
The principal reason for reduced lifespan of CFLs is heat. CFLs exhibit shorter lifespans in light fixtures and sockets where there is low airflow and high heat build-up such as recessed lighting. For these types of sockets it’s recommended to use specially designed CFLs for recessed lighting or LEDs. Another main reason for reduced lifespan of CFLs is too-frequent on/off cycling. These bulbs should be used where they will be left on for steady periods without being flicked on and off.
Mercury and CFLs
Mercury is a toxic metal associated with contamination of water, fish, and food supplies, and can lead to adverse health effects. A CFL bulb generally contains an average of 5 mg of mercury (about one-fifth of that found in the average watch battery, and less than 1/100th of the mercury found in an amalgam dental filling). A power plant will emit 10mg of mercury to produce the electricity to run an incandescent bulb compared to only 2.4mg of mercury to run a CFL for the same time. The net benefit of using the more energy efficient lamp is positive, and this is especially true if the mercury in the fluorescent lamp is kept out of the waste stream when the lamp expires.
Handling and Disposal of CFLs
The mercury in compact fluorescent bulbs poses no threat while in the bulb, but if you break one:
- Open a window and leave the room for 15 minutes or more.
- Use a wet rag to clean it up and put all of the pieces, and the rag, into a plastic bag.
- Place all materials in a second sealed plastic bag.
- Call your local recycling center to see if they accept this material. If not, and you’re located in the U.S., review the list of companies accepting CFL’s by mail maintained by the Environmental Protection Agency.
- Burned out CFLs can be dropped off at Home Depot and Ikea stores.
- Another solution is to save spent CFLs for a community household hazardous waste collection, which would then send the bulbs to facilities capable of treating, recovering or recycling them.
- For more information on CFL disposal or recycling, you can contact your local municipality.