Boat Lights: LED, Versus Halogen, Versus HID

LEDs have generated a lot of interest among boaters over the last several years due to their high efficiency, powerful output, and unheard of longevity. Although early LED offerings were lacking in light quality and lumen output, rapid advancements in LED lighting technology have for all intents brought LEDs up to par and now they are considered a superior alternative to almost every other type of light source. This is not to say that traditional light sources are no longer worth consideration, but as LEDs continue to increase in quality and output, justifying the use of other lighting designs is becoming harder and harder to do. To see just how effective LEDs have become, let's take some time to compare some performance averages across the three main types of standard boat light types.
Halogen-
Halogens have been a longtime favorite among boaters due to their good power and affordable purchase price. There is often some confusion as to whether or not a halogen bulb qualifies as an incandescent light source, but the basic design is the same, only halogens contain added halogen and or bromine gases. The addition of these gases causes a reaction with the tungsten filament which results in vaporized tungsten being re-deposited on the filament as the lamp is operated. This increases the longevity of the lamp and allows it to run at higher temperatures, which in turn improves the color quality and overall lumen output of the bulb. However, halogen bulbs are as we mentioned, at their core a basic incandescent design, and like all incandescent bulbs are highly inefficient and relatively short lived. Some specs for a typical 50 watt halogen bulb commonly used on boats are listed below.
17-20 lumens per watt output.
2800-3400 Kelvin color temperature.
Lamp life 1700 - 2500 hrs.
Color rendering index 100.
1,500 to 2,000 hour operating life.
Very hot operating temperature.
Fragile wire filament can break under abusive conditions.
HID-Metal Halide-
HID bulbs produce light differently from halogen or LED light sources and represent some of the most powerful types of lighting available. Most HID bulbs used onboard boats are of the metal halide variety, which produces high output combined with good color quality and good longevity. HID lights are more commonly used in spotlights due to their intense output, but also see significant use in spreader applications where larger amounts of deck area need to be covered with substantially high lumen levels. HID lights produce light by creating an arc within a glass bulb that ignites gases and metallic salts to create a plasma ignition, in turn creating intense light output. HID lights are very efficient, have good longevity, and like halogen lamps produce large amounts of heat. For applications requiring the most powerful light output possible, HID systems are at the top of the list. The following are some basic performance specs for a typical 50 watt HID bulb.
Lamp life 5,000 - 20,000 hrs (varies greatly according to wattage).
2700K to 20,000 Kelvin color temperature.
75-95 Color rendering index.
Very hot operating temperature.
Erratic operation when bulb nears end of life rating.
Slow warmup, slow hot restart.
Requires ballast assembly for operaton.
Solid State Lighting- LEDs-
LEDs represent the newest generation of boat lighting technology and provide an excellent alternative to halogen and metal halide lamps. LEDs also produce light much differently than halogen or HID bulbs. LEDs consist of thin layers of semi conducting material coated with materials such as phosphorus which is affixed to a metal base and fed current through two contacts. When electrical current is passed through an LED, a process called electroluminescence takes place where in electrons pass through the semiconducting material and as they do they eventually release some energy in the form of photons, or visible light. This process is very efficient, produces low amounts of heat as compared to the amount of light produced, and works natively with direct current rather than alternating current.
Although LEDs do produce far less heat than incandescent or HID lamps, the LED chip itself is more sensitive to high heat levels, and it is possible for too much heat buildup to damage the LED and shorten its operating life if not dealt with. Because of this most manufacturers design LED fixtures with built in heat sinks, represented by finned housing designs which work to efficiently dissipate heat and maintain maximum performance. This heat management issue and heat management solution is why most LED fixtures look so different from standard lamps and is the leading source of trouble with LEDs, but these days most manufacturers of quality LEDs have produced designs which effectively reduce the issue to a minor one. The following are some basic specs for an LED equivalent to 50 watt halogen lamps.
60-100 lumens per watt output.
Lamp life 20,000 - 100,000 hrs.
2,700 to 7,000 Kelvin color temperature.
60-90 Color rendering index.
Very cool operating temperature.
Instant on, no warmup.
Voltage sensitive and requires additional voltage managing circuitry.
No glass, no filament, highly durable.
If we look at these basic specifications we can easily see why LEDs are now so popular with boaters. Highly efficient, cool running, and extremely long lived, LEDs represent an almost tailor made lighting solution for boat illumination. LEDs can easily replace halogen lamps for almost any type of onboard installation, and their small size and cool operation means you can install them in cabins without the need for bulky fixtures or worries about potential fire hazards. Although LEDs don't as of yet have to intense output of HID lamps, they still provide comparable output that is quite effective when used in applications requiring significant beam reach or coverage of large areas. LEDs don't need any warmup time to reach full operating output, and since they are solid state can handle the vibrations and impacts that come with running through rough seas.