By Tom Salpietra, President & COO, EYE Lighting International
Since street lighting became popular in the U.S. in the last half of the 1800s, the light source has migrated from natural gas to mercury, then to sodium lamps, and now to LEDs. While the ordinary “cobra head” and shoebox are the most common luminaire designs found on top of light poles today, over the years many cities invested in historically styled lighting fixtures for their downtown shopping and residential streets because they contribute to the safety, quality, and ambiance of the local experience.
World-famous thoroughfares such as State Street in Chicago, Broad Street in Philadelphia, the Embarcadero in San Francisco, and Peachtree Street in Atlanta have all installed historically styled lighting fixtures for many years.
Retrofitting Historical Lighting
Colleges and universities have similarly adopted period-style lighting to enhance campus appearance and provide security and illumination. Many institutions had special designs made, often by hand, in an effort to capture a particular historical significance for which the institution stands. Maintaining the iconic symbol of the light post and fixture is as important as the dorms, libraries, and campus greens with which the school attracts freshmen and welcomes visitors.
Over the last decade, as budgets tightened and the pressure to reduce operating expenses increased, the need for replacing energy-inefficient light fixtures across neighborhoods, downtown areas, and educational landscapes became a major initiative.
Going green has been at the center of changing traditional light sources to solid-state lighting (SSL). Carbon emissions, global warming, and the urge to do the right thing spurred mayors, city councils, and colleges to look at options for lowering operating expenses while becoming environmentally friendly.
What are the alternatives for retrofitting historical or decorative lighting fixtures with LEDs? How can cities and educational institutions keep their distinctive looks but move in the direction of SSL technology?
U.S.-based lighting manufacturers—the backbone of American industry—and particularly NEMA members who contributed to the association’s 90-year history, came up with solutions. Working with municipalities, utilities, and co-ops, many lighting companies designed new luminaires to replace traditional, decorative-style light fixtures. Others have turned to retrofitting existing light fixtures with LED kits, designed to operate in the same manner as the traditional light source but with an energy-efficiency focus. These approaches serve the same end-game for achieving lower energy costs.
The challenge though with designing and developing any new SSL luminaire or LED retrofit kit is the ability to capture the performance as well as the aesthetic appeal of the product it is replacing. In many applications, newer, sleeker designs with controllability to dim or turn lights on-off remotely are desired, as are energy measurement and monitoring. In others applications, the networked solutions are less appealing and the desire is to maintain the traditional appearance of the installation is preferred. Here is where retrofit kits are the better choice.
LED retrofit kits come in a variety of shapes and sizes. Until now, most are the screw-base Edison-style design. Others are special designs made by some manufacturers to fit inside their own historically-styled product line. Still others are designs that are more universally applicable to a number of post top fixture constructions. In every case though, the performance and longevity of the LED retrofit kit are things the owner of the luminaires expects to be standard, and not validated by the end-user for thermal, optical or electrical characteristics.
Preserving Heritage and Saving Energy
Some of the kits on the market today, known as corncobs, present challenges for all of these performance characteristics if they haven’t been pre-tested in each fixture. Other kits which have been pre-tested by the manufacturer present a less challenging option, provided the kits fit within the framework and geometry of the luminaire.
The Design Lights Consortium approves products for utilities who sometimes offer rebates on LED upgrades to municipalities, educational institutions, and privately-owned facilities. The Department of Energy, in collaboration with the consortium, established guidelines and recommendations for validating the performance characteristics of LED Retrofit Kits for post tops. If the product is not on the Qualified Products List, it is a caveat emptor scenario for customers.
Interest in keeping the existing fixture and using an LED retrofit kit is increasing among owners of historically-styled streetlights. Not only is energy-savings inherent in the SSL technology, but there is an additional benefit in reducing landfill waste by recycling the existing luminaire. In many cases, the retrofit installation is just as quick, if not quicker than changing out the entire fixture head—but only if the design is right.
Although many city engineers are wise to this issue, others do not recognize that installation time is often a hidden cost. They are advised to try a sample installation and evaluate the entire cost cycle, as well as the visual appeal, of the retrofitted fixture. The reliability and maintenance-free benefits of LED lighting, especially a retrofit, can only be achieved by looking to NEMA-level manufacturers who make quality products and provide quality service.
After all, the post-top light that casts its soft beam onto downtown window-shoppers, night-time runners, and families and lovers that stroll through local parks is iconic to our American heritage.
This piece was originally published in the February 2016 issue of ei, the magazine of the electroindustry.