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LD+A The Magazine of the Illuminating Engineering Society of North America

LED Testing & Application

Second Takes the Lead

A forerunner in implementing wirelessly controlled LED technology, Los Angeles’s street lighting program is second in size only

BY ELIZABETH HALL

Being number two doesn’t always mean coming in second. Take Los Angeles. The city maintains the country’s second largest number of municipal streetlights, but its program is first rate. In fact, the Bureau of Street Lighting’s five-year plan to convert 140,000 of its 209,000 high-pressure sodium streetlights to LED technology is the largest LED street lighting replacement program currently planned in the world, according to the Clinton Climate Initiative, which helped facilitate the project.

Launched in 2009, the $57 million LED Street Lighting Energy-Efficiency Program has resulted in the installation of 52,000 streetlights to date—besting its third-year goal of 50,000. (By comparison, the largest municipal program in the U.S. is New York City, which maintains a total of 300,000 streetlights and is scheduled to install its new custom-designed LED streetlights this month.) These streetlights are subject to rigorous in-house and in-field testing to ensure they meet Los Angeles’s minimum LED fixture requirements, which include energy saving, performance and fabrication criteria.

In addition, the Bureau sought to go beyond the current needs of its street lighting requirements and prepare for the future by endowing the new lights with remote monitoring capabilities. (It currently uses Acuity’s Remote Operations and Management, or ROAM, devices.) As of August, 38,000 of Los Angeles’s 52,000 installed streetlights have been outfitted with ROAM technology, which streamlines maintenance operations and monitors energy usage in real time.

LA EVALUATES LED
Like many other cities, Los Angeles’s quest for a better streetlight began with the desire to conserve energy. It quickly morphed, however, into a way to increase pedestrian safety in some of the city’s notoriously dangerous neighborhoods. “We tried to target high crime areas of the city because we received positive feedback from law enforcement after testing out LED streetlights,” says Bureau director Ed Ebrahimian. “White light makes a huge difference. It has better color rendering.” In fact, “the police helicopter support in those areas thinks that we increased the lighting by five times. We really just matched the same light levels; however, the white light gives the perception of increased brightness.”

Photo: BetaLED

Ebrahimian is quick to add that not all white LED streetlights are created equal. To separate the wheat from the chaff, the Bureau created comprehensive fixture testing procedures. The first step in evaluating fixtures was to develop minimum fixture specifications. “When we started there were no specs,” says Ebrahimian. “So, we set our specs based on IES standards and the best available technologies. We saw what each manufacturer could offer, picked the best components of those manufacturers and put them together to create the spec.” The Bureau then began to accept submissions from manufacturers whose products met the minimum specs.

Some municipalities would have stopped there, but Ebrahimian wanted to ensure that the city spec could evolve to accommodate improvements in LED technology. So the Bureau held another open evaluation six months later, and again six months after that. It continues to test new samples every six months, and updates its specifications to reflect the best of what is on the market, as well as the most current IES and DOE recommendations.

Currently, the specifications require each LED fixture submitted for evaluation to consume 45 percent less energy than its commercially available HPS counterpart; meet IES lighting standards as outlined in RP-8-00; and feature a power factor of .9 or greater, 4,000K CCT (plus or minus 275K) and 65-plus CRI. All submissions must also include documentation of independent lab testing along with IES LM-79 files.

If a sample meets the minimum requirements then it undergoes in-house performance testing, electrical field testing, illumination testing, and evaluation from both the Bureau and the local community. The various tests evaluate the fixtures according to five criteria: electrical performance, mechanical performance, illumination performance, ease of maintenance and aesthetics. So far, fixtures from two manufacturers have made the final cut and have been installed throughout the city: BetaLED’s LEDway luminaire and Leotek’s GC1 fixture.

LOOKING AHEAD WITH ROAM
The Bureau undertook a similar process to determine the best remote operation system to control the LED fixtures. After evaluating five proposals, it selected Acuity’s ROAM technology, which uses wireless photo controls that are installed on each fixture to monitor outages and energy use. Initially, the Bureau saw ROAM as a safety net. “The main reason why we put in ROAM was because we were working with brand new technology at the time—LED—and we couldn’t afford to send the resources out to the field everyday to make sure they are working. If there is a remote monitoring unit, it communicates to us if they go bad,” says Ebrahimian.

ROAM photos courtesy of Acuity Brands Controls

Of course, one of the biggest perks of LED is its long lifetime, which translates into fewer outages and would seem to minimize the need for ROAM. The irony isn’t lost on Ebrahimian: “Of course, with LED there is virtually no maintenance.” But, he adds, “in addition to maintenance monitoring, ROAM has given us a lot more information, and now with the dimming capabilities of the drivers and fixtures that are being developed, ROAM can control the driver and light output. You can have the option of reducing light at certain times, which is something we are not utilizing yet, but it’s an important tool to have for the future.”

ROAM has also equipped the city with another tool for the future—the ability to measure its actual energy use, which would complement smart meters should the local utility decide to implement them. For now, the Bureau pays the city-owned utility according to the manufacturer’s stated nominal wattage per fixture, a number that is verified by independent lab tests and the Bureau’s own in-house testing. “But utilities are changing and moving towards smart meters,” notes Ebrahimian. “That’s what ROAM is. It’s a smart meter installation that tells us exactly how much power is being used everyday.”

According to the most recent data, the new LED streetlights have saved the city 21,553 MWh per year compared to the old HPS lights (a nearly 60 percent energy savings), resulting in annual energy savings of more than $1.9 million. At the current rate and with current luminaire pricing, the city’s ROI has been reduced from the initial estimate of seven years to six years. In addition, the Bureau was able to offset approximately $16 million of the $57 million total project cost with utility rebates.

Energy reporting and dimming may help improve the Bureau’s operations in the years to come, but it’s getting at least one benefit from ROAM right now. In case a light does go out, “you don’t need to rely on citizens to call you to let you know that it’s out,” says Ebrahimian. “The notice is downloaded in our service request system and distributed among crew leaders so that when they arrive in the morning they can see what needs to be repaired. It gives me peace of mind.” And that’s priceless.

Photos courtesy of BetaLED

October 2011