The anniversary is a good time to take a closer look at the results and lessons learned, with more than 80% of the LED fixtures planned for phase one deployed. The lessons learned are based on a presentation delivered by Ed Ebrahimian, Director, Los Angeles Bureau of Street Lighting, to the IES Street and Area Lighting Conference convened in Miami in September 2012. (Here is a presentation [PDF] Ebrahimian delivered at the DOE Municipal Solid-State Street Lighting Consortium Workshop held in Los Angeles, in April 2012, with much of the same information.)
1) Energy savings are real: “As the LEDs improve, and the manufacturers develop the technology, the energy savings are being realized and continue to increase,” wrote Ebrahimian. At the outset, city planners estimated LED fixtures would achieve a 40% electricity savings over HPS units; as noted above, the actual savings is more than 63%. In 2008, Los Angeles spent $16 million for the electricity to run its street lights. When the LED retrofit is completed, annual electricity savings should reach $7.5 million.
According to the city, the $57 million project, funded through a combination of energy rebates, the Street Lighting Assessment Fund, and a $40-million loan, will be repaid over seven years through electricity and maintenance savings alone.
2) Maintenance savings are real, too: In 2008, pre-LED roll-out, Los Angeles logged 70,000 street light repair and maintenance events; in FY 2012, maintenance and repair events fell to 46,300. LEDs are longer lived than the incumbent units they replace (10-15 years versus 4-6 years), which means that maintenance should steadily decline as LED units are fully deployed. A remote monitoring system, installed with the LED fixtures, indentifies problems in real time.
LED fixtures also fail at a lesser rate than incumbent technologies. After 36 months of initial operation, for instance, high-intensity discharge (HID) fixtures in Los Angeles recorded an average failure rate of 10%; the average failure rate for LED fixtures, according to the latest figures, is 0.2% (189 of 98,000 installed). At full LED deployment, Los Angeles expects to save $2.5 million annually on maintenance costs.
3) Trust but verify: “Not all claims manufacturers make are true,” noted Ebrahimian. Los Angeles tests new LED fixtures every six months. Manufacturers interested in selling LED fixtures to the city can submit products for testing at the Bureau of Street Lighting website. City specifications are revised based on testing results and technology improvement.
These improvements, coupled with falling production costs, have yielded a reduction in per unit cost. At the time of Ebrahimian’s Miami presentation, September 2012, the per unit cost was $309 (85% materials, 10% engineering, and 5% labor); when Ebrahimian delivered his talk in Los Angeles six months before, the per unit cost was $495.33.
So far, manufacturers have requested evaluation of 244 LED units; 84 met the minimum requirements; 71 were installed and tested; and 20 units were approved for use. Approved LED fixtures for so-called “cobra head” street lights include: Cree’s XSP series and LEDway series, Hadco’s RX series (Hadco is a Philips company), and Leotek’s GC series.
4) Reality versus theory: “The change from HPS to white light with the LEDs is being perceived as a significant increase in lighting levels,” according to Ebrahimian. He added: “The change from HPS to white light [LEDs] have improved visibility as noticed by residents and encouraged by the police department.” In short, the city anticipated negative community feedback but citizens seem pleased with the change.
Though it is likely one among many factors, improved visibility in residential areas, where most of the LED fixtures have been installed, may be connected to a reduction in crime. From 2009 to 2011, citywide crime statistics show a decline in incidents between 7 p.m. and 7 a.m. (vehicle theft: -13.6%; burglary/robbery/theft: -7.82%; and vandalism: -10.9%).
Looking ahead, Los Angeles is testing and evaluating LED and induction units to deploy in phase two of the street lighting conversion, when the city will replace fixtures in 70,000 decorative street lamps.