Airport LED lighting application issues (I)

In the United States and other countries, light-emitting diodes (LEDs) are being used in airport lighting. The purpose of this comprehensive study is to provide data on the performance of LED airport lighting systems, mainly for airport operations managers and electrical maintenance personnel. Information about the performance, cost and other operational aspects of LED lighting systems is difficult to attribute to a single point. This report is the result of collecting feelings and feedback from the use of LED airport lighting.

The researchers conducted a literature review and surveyed individuals who had used LED airport lighting. Individuals from 22 airports and aviation agencies agreed to participate in the survey and all completed the task (100% response rate).

The results of the study show that LED airport lighting reduces energy consumption and maintenance requirements compared to traditional airport lighting technology. LED airport lighting systems have been used for many years, and most of the feedback on visibility and performance has been positive. Through technological improvements and the efforts of the FAA (Federal Aviation Administration) to promote the guiding role of LED technology in airports, the compatibility issues that appeared in the early days have been largely improved.

In the airport lighting system, most of the power systems were originally designed for incandescent lighting technology, so LED airport lighting systems are not compatible with this infrastructure. However, by replacing part of the power infrastructure and simply replacing incandescent lamps with LED lamps, energy utilization and reliability can be greatly improved.

Although the initial cost of using LED lamps is higher than that of traditional incandescent lamps, the reduction in energy consumption and maintenance cost savings may pay for the initial high cost after a few years. The maintenance requirements of LED airport lighting systems are much lower than those of incandescent systems, and future research directions can pinpoint the economic impact of this aspect.

background:

Light-emitting diodes (LEDs) are increasingly being used in a wide variety of safety-related applications, including evacuation signs (Boyce 1994), road traffic signals (Conway and Bullough 1999), automotive brake and turn signals (Olson 1987), street lighting (Radetsky 2010), and airport lighting. Several features of LEDs make them popular in visual signaling applications. (See also Appendix A for a description of LEDs and a comparison of LEDs with incandescent light sources.)

Durability and long life of solid-state devices

Wide range of available colors (including all aviation signal light colors)

Narrowband wavelength output produces saturated colors

Relatively low energy requirements

Instant switching times

Currently, most airports use primarily incandescent filament bulbs, which have a shorter useful life than LEDs. The typical working life of an incandescent bulb is in the hundreds to thousands of hours (Bullough 2000). In contrast, a well-designed LED lighting system can last for tens of thousands of hours.

Incandescent lamps also have lower luminous efficacy (lm/W) than LED light sources, and accordingly, require more energy. Due to the low efficacy of incandescent lamps, the enactment of energy laws such as the Energy Independence and Security Act (EISA) of 2007 has accelerated the replacement of traditional incandescent lamps in many lighting applications. Although EISA does not directly affect airport lighting, the rapid advancement of ordinary incandescent lighting replacement has contributed to the great interest and application of LED signal lights in American airports.

Some differences between LED and incandescent technology may be seen as possible barriers to wider adoption of LED airport lighting. The narrow spectral output of LEDs means they do not generate infrared energy (heat), which can help melt accumulated ice and snow in very cold weather. LED airport lighting must be compatible with the existing specialized electrical infrastructure for airport lighting.

In addition, since the initial cost investment of LED lights is much higher than that of incandescent systems, whether the technical advantages of increased service life and reduced energy consumption can make up for the high initial investment will be of great concern. This comprehensive study was conducted through the ACRP (Airport Cooperative Research Project) of TRB (American Transportation Research Board), collecting information from literature, airports and other institutions that have used LED airport lighting to help airport operations and maintenance personnel consolidate and screen issues related to this emerging technology. The experience learned from airports that have applied this technology will help other institutions face various issues such as whether to install LED airport lighting, when to install it, what questions there will be, and what expected benefits and difficulties.