The City of Palo Alto is currently upgrading about 10% (600) of its high pressure sodium (HPS) street lights with better quality, longer lasting and more efficient Light Emitting Diode (LED) light fixtures as the first step in replacing all City-owned street lights. This project is funded through a $450,000 Federal Stimulus Grant, also known as the American Recovery and Reinvestment Act (ARRA).

These new LED fixtures are expected to provide better lighting quality, as well as to reduce energy usage in Palo Alto each year by 369,000 kilowatt hours, which will save about $30,000 annually. Over a five year period, the City plans to replace all of its 6,300 HPS street lights with LEDs, which could potentially reduce electricity usage by over 1.6 gigawatt hours and avoid the emission of nearly 650 metric tons of greenhouse gases per year. 

Before deciding which lamps to use in the upgrade, the City conducted a pilot program to gather data and community feedback. The City gathered feedback over two summers from the local community in the test areas and from Palo Alto Police Department staff, as well as from Utilities Department employees who currently maintain the HPS street lights. To obtain a broad range of feedback about the streetlights, the City also sent a letter with a survey form enclosed to 200 residents living near the test sites, solicited feedback on the City of Palo Alto’s website (www.cityofpaloalto.org/streetlightpilot)  and posted signs on the poles of each test street light to showcase the technology.  Additionally, the City and Palo Alto Neighborhoods (PAN) jointly hosted an evening walk-through tour to solicit in-person reactions from residents.

Overall, respondents preferred the LED street lights over the other lighting choices. Improved color perception and increased visibility were cited as key advantages of the LEDs. While HPS lights put out a yellowish glow, LEDs emit a white light that makes the surrounding area have a more natural color and improves visibility at street level for cars, pedestrians and bicyclists.

While the initial cost of the LED lights is higher than for the current HPS lights ($542 versus $78 per bulb), the ten-times longer lifetime of the LEDs makes them cheaper in the long run, primarily due to the difference in maintenance costs. With these lower operating costs and the reduced use of electricity, the projected payback for replacing all existing HPS lights is 11 years.

After comparing lights from different manufacturers, staff prepared a competitive bid for the purchase. Twenty manufacturers responded and City staff recommended to the City Council that LeoTek fixtures be purchased.  The LED street lights have state-of-the-art technology with excellent thermal management and weather resistance capabilities. They will be installed on the existing street light utility or traffic signal poles in residential or commercial areas. The light fixtures are manufactured to comply with City of Palo Alto specifications and industry standards and have a 10 year warranty. 

“With this purchase, Palo Alto will join San Jose, Menlo Park and many other cities in the area in moving to the new technology,” said Valerie Fong, Director of Utilities. “The lighting quality will meet or exceed that of current fixtures, and the community will save both electric and maintenance costs to replace bulbs, while reducing green house gas emissions.”

The City Council approved this purchase at its November meeting, and the lights are expected to be installed early in 2011.