LEDs (Light Emitting Diodes)  are small, solid light bulbs which are extremely energy-efficient. Until recently, 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 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 which fit common household light fixtures, LEDs are the next generation in home lighting.

The high cost of producing LEDs has been a roadblock to widespread use. 

However, researchers at Purdue University have recently developed a process for using inexpensive silicon wafers to replace the expensive sapphire-based technology. This promises to bring LEDs into competitive pricing with CFLs and incandescents. LEDs may soon become the standard for most lighting needs. 

Benefits of LED lightbulbsLong-lasting - LED bulbs last up to 10 times as long as compact fluorescents, and far longer than typical incandescents. 

Choosing an LED lightbulb 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 wattage - read the package to choose desired illumination level. For example, a 3W LED is equivalent in output to a 45 W incandescent.

• 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.

The common styles of LED bulbs include the following: Recessed/Track bulbs

Available in pin base or standard (Edison) base, LEDs are ideal for track or recessed lighing. LEDs do not contribute to heat buildup 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

incandescants, the frequency of changing bulbs is greatly reduced. 

Diffused 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 a range of wattage and sizes, these bulbs have many uses, such as area lighting for small rooms, porches, reading lamps, accent lamps, hallways and low-light applications where lights remain on for extended periods. 

Spotlight and Floodlight LEDs The spotlight LED lacks a dispersing lens, so it appears brighter as its light is directed forward. The floodlight model gives a spread-out dispersed light. Well suited for ceiling lights, outdoor floodlights. Retail display lighting, landscape lighting and motion sensors. 

LED Colors 

Red - red is the traditional color for maintaining night vision.

Green - green is now the preferred color for pilots and the military. The green color is also great for retaining night vision, and it doesn’t erase the red markings on maps and charts.

Blue - many people like the blue because it is very easy on the eyes. Blue appears to be a good reading light for elderly eyes. Elderly folks report that they can read under the blue light for hours without eyestrain, compared to severe eyestrain in less than 30 minutes with incandescent lighting.

White - the most popular of the LED colors. It produces a soft white light, without harsh reflection, glare or shadows.

Amber - LED amber bulbs do not attract flying insects, as do ordinary white bulbs. Amber LEDs are used outdoors in areas such as patios and decks where insects flying around lights are a nuisance.