Most of us have become familiar with the term “LED” (or Light-Emitting Diode), but I wanted to cover what a LED really is and why it is better in every way than a typical incandescent light bulb in nearly any application. The principle behind the LED was discovered in the early 1900’s, but it wasn’t until the late 1960’s that anyone developed an affordable LED product. These early LED’s were typically used as indicator lights on instrument panels or in calculator displays. An LED is a solid state device which emits energy in the form of photons when an electrical current is passed thru a specially selected semiconductor alloy material. This effect is called electroluminescence. The material chosen determines the color of the light emitted by the LED. In contrast, an incandescent light bulb uses a thin wire filament which is heated by passing current thru it. The heated filament glows and also emits light in the form of photons. The filament also is enclosed within a glass bulb that is either filled with an inert gas or evacuated, protecting it from oxygen, which would cause the filament to burn up. As you can see, in an incandescent bulb, the light emitted is a byproduct of heating the element, thus the large amount of heat generated by incandescent bulbs.

Now to cover the advantages of LED’s versus incandescent light bulbs:

1. Due to the physical differences in design mentioned above, LED’s use far less energy than incandescent bulbs. In fact, they use less than 15% of the energy for a comparable light output. This obviously means that your battery will power LED lights for a longer period (roughly 7 times as long) and your generator or alternator will have to do less work to power LED products, ultimately saving fuel and reducing exhaust emissions.

2. LED’s are much more robust and reliable as they do not have a delicate filament that is subject to damage due to vibration or shock and naturally burns up after a relatively short service life. On average, the life span of a LED is roughly 40 times that of an incandescent!

3. LED’s are smaller in size because they do not require an evacuated or inert gas filled chamber within which to operate and do not have a relatively long filament.

4. LED’s are faster switching, which means their light is visible to the eye sooner when activated than an incandescent, which must heat up before emitting light. This is why LED’s have become popular in brake light and emergency flashing light applications.

5. LED’s emit less heat than an incandescent light bulb which is a safety improvement in terms of fire and burn risk and can help to improve comfort within a confined space such as a boat cabin or small camper or RV. In fact, on the order of 90% of the energy consumed by an incandescent light bulb is emitted as heat.

6. Since it does not include a glass enclosure, LED’s do not present the same dangers as incandescent bulbs which can be broken by even minor impacts, exposing sharp glass edges and the hot filament.

In terms of disadvantages, the only one would be cost in some applications, particularly when it comes to high intensity light output applications such as automotive headlamps. High intensity application of LED’s require special circuitry and generate a significant amount of heat as well. However, in most other applications the cost of LED technology has become competitive with incandescent, especially when you consider the much longer service life and lower energy consumption.