Halogen Lamps Cannot Compete with LED in Landscape Lighting

December 30, 2007

Halogen lamps have been the standard in low voltage landscape lighting, but LED lamps are more efficient, last longer, and are more cost-effective.

Most of us are familiar with standard incandescent lighting as we have used them in our homes years. Halogen lighting, however, is less common. A halogen lamp is a type of incandescent lamp. It produces light in the same manner that a standard incandescent lamp produces light; that is, by running electrical current through a resistant filament--a process which creates heat which in turn produces light. The difference between standard incandescent lamps and halogen is the type of case inside the bulb. Standard incandescent landscape lights are filled with nitrogen or argon. In contrast, a halogen lamp is filled with halogen gas. When heated to a very hight temperature the halogen gas will bond with the vapors from the tungsten filament and redeposit them on the tungsten filament. This process essential self-repairs the tungsten filament that deteriorates as it burns. The end result is that the halogen bulb lasts much longer than a standard incandescent because of the self-repairing filament. However, halogen lights produce an incredible amount of heat and therefore are not very efficient. The intense heat they produce also creates a fire hazard.

Despite its inefficiency, halogen lamps have been the standard in low-voltage landscape lighting because of the intense light that can be produced by a small lamp. A standard glass halogen lamp produces about 16 lumens per watt. Thus, a 20 watt glass halogen landscape lighting lamp would produce 320 lumens. This lamp has an approximate life span of 10,000 hours or a little over a year.

LED lamps, or light emitting diodes, are a new lighting technology that are highly efficient and long-lasting. A new high performance LED can produce over 100 lumens per watt which is more than 6 times more efficient than halogen. Thus, a 3 watt LED lamp can produce the same amount of light as a 20 watt halogen lamp. In addition to the extreme advantage in efficiency, LED landscape lamps last much longer than halogen. A high quality LED can last for more than 60,000 hours--6 times the life of a halogen lamp or about 7 years.

If you illuminated one 20 watt halogen lamp for 8 hours each day for a period of one year the approximate cost would be $6.42. A comparable LED lamp would cost $1.02 to operate for the same period. When one considers that most landscape lighting systems use 15 or 20 lamps this adds up quickly.

Additionally, at the end of the first year the halogen lamp is at the end of its life and may only last a few months longer while the LED lamp is just getting broken in. The additional cost of halogen replacements and the labor cost in replacing the old halogen lamps over the 6 year life of the LED amounts to an additional savings factor that cannot be overlooked.