As Solid State Lighting (SSL) LED lighting fixtures have become more common in municipal and urban planning, the federal government has started to take notice of the benefits of LED lighting as well. Recently the Department of Energy conducted some research on SSL LED fixtures to compare their performance in high temperature outdoor environments to the standard high-output quartz metal halide (QMH) lighting fixtures.<\/p>\n
To do this the Department of Energy replaced three of their current QMH luminaries with LED fixtures along a stretch of the US-Mexican border fence near Yuma, AZ. The reason for the testing was first and foremost to be able to quantify the energy saving benefits and lower cost of LED systems. The second goal was to test these SSL LED systems because heat and the harsh desert climate is a challenge to the durability and quality of many lighting systems. These systems would need to be both cost effective and highly durable to withstand regular day-to-day temperatures of over 100 degrees Fahrenheit (even at sunset) for them to be considered a practical alternative to QMH fixtures.<\/p>\n
The problem with operating lighting fixtures under these conditions is that continuous high temperatures can have negative effects on the semiconductor junctions which can significantly shorten their lifespan. As if the exterior environment wasn\u2019t enough of a concern, the area that needed to be lit required high light levels to ensure national security and reliable operation every night.<\/p>\n
The initial results of the Department of Energy study were very positive. Not only did the LED lighting fixtures withstand the harsh high outdoor temperatures and dusty environment, they also exceeded the initial expectations for lighting quality. The LED fixtures provided much superior lighting, easily illuminating the areas necessary AND they were able to do this while being mounted lower than the standard QMH fixtures. This would make both setting up, and maintaining these fixtures much easier and more cost effective. With regards to energy efficiency the LED fixtures again exceeded expectations, providing a 69% increase in energy savings, and lower light pollution.<\/p>\n