From airports to bus shelters, casinos to theaters, and streets to roadways, backlit display lightboxes highlight advertising and wayfinding messages in public spaces. For example, there are approximately 4,250 malls in the U.S. According to the 2009 Directory of Major Malls, each mall includes a range of two to 50 lightboxes used for advertising and directional signage. Approximately 85,000 large lightboxes are bringing light to retail messages in malls across America on a daily basis. If we take into consideration that display lightboxes can be freestanding, surface mounted or recessed mounted into a wall, and are commonly used for advertising in fast-food restaurants, airports, bus shelters, train stations, stadiums, shopping malls, retail outlets and theaters, the number of backlit display lightboxes in the U.S. is impressive.

This large number also represents a candidate market for emerging energy-efficient lighting technologies that can reduce the amount of electricity used for each of these units. In order for the new technologies to succeed, the message they carry must maintain or improve on the current visual qualities of the boxes. Display lightboxes involve inserting a transparent image into a boxed housing that is backlit by a light source. Lightboxes have traditionally incorporated fluorescent lamps, but in recent years, cold cathode fluorescents (CCFL) and LEDs have been introduced as alternatives. In order to compare these three light sources, San Diego Gas and Electric partnered with the California Lighting Technology Centers (CLTC) at UC Davis to study the performance characteristics for fluorescent lamps, CCFL and LEDs used in lightboxes. Ultimately, San Diego Gas and Electric will use studies such as this one to determine whether backlit lightboxes using alternative light sources qualify for utility incentives.