The U.S. Department of Energy published a Gateway report that outlined the conversion of high-pressure sodium streetlights to LED-based models in the City of Portland, Oregon. The report pointed out that the city is midway through the process of converting its street lighting system. So far, the city has purchased a large portion of its street lighting system. The city encountered a range of both expected and unexpected issues among the project’s stakeholders. The report points out that these issues may be more or less common to other municipalities seeking street lighting purchases and conversions.
The report identifies some of the challenges the city encountered and describes how the city addressed them to help inform and facilitate future lighting transitions in other municipalities. The DOE also included preliminary discussion of the results and lessons learned.
The report makes several recommendations based on lessons learned from the Portland project. The report recommends that an appointed project leader should offer an effective communications strategy. This leader should implement new agency standards and should be able to see both sides of an argument and remain flexible in finding fair compromises.
Project estimates should for the sake of long-term cost estimates assume that private sector partners would complete any maintenance work in a manner similar to a city with a public utility. The report noted that this assumption eliminated a key argument of the utility that ongoing costs would be less than if City personnel conducted the work.
Municipalities in the region formed a collaborative and approached the utility collectively so that the utility would be more responsive to its customers regarding a requested rate tariff to include LED technology. The collaborative also helped the municipalities buy with bulk pricing. The report recommends the use of independent consultants or agencies to prepare a technical and financial analysis that will lend credence to the numbers they provide.
The city encountered one issue that is likely very common with street light projects. According to the report, the Portland Bureau of Transportation (PBOT) received requests to reduce “brightness” in the stages of installation. These requests were made despite the fact that the lumen output of the LEDs was already significantly lower than the HPS products they replaced. The report noted that lighting with a generally higher color temperature in combination with a smaller aperture (i.e., area from which the light emanates) leads to a common perception of LED lights as being “brighter” than the products they are replacing. PBOT eventually chose the lowest luminaire output setting as the default in residential neighborhoods. The report suggested that conducting multiple mock-ups with open invitations for public input may help identify such issues earlier.
Notably, the PBOT worked with three other agencies: the Office of Management and Finance on developing financing strategies; the Bureau of Planning and Sustainability to support the benefits of the project and allow a portion of the savings to be used to purchase green power; and the Parks and Recreation Bureau in offering to include their lights in the conversion. The report found that the level of collaboration and the resulting momentum greatly contributed to the Portland City Council’s unanimous support for the project.
The city hopes to use the substantial savings that the project will achieve for numerous related purposes. For example, the PBOT intends to use some of the savings to fund infills to currently underserved neighborhoods, where previously the only option was a neighborhood “buy a light” program.
The city used off-the-shelf geographic-information system (GIS) digital tools. These GIS tools helped to streamline Portland’s conversion process and offered capabilities that would not have been available otherwise. PBOT carefully constructed the GIS-based system to enable simultaneous, real-time updates to the street lighting inventory. The real-time inventory update capability allows engineers and technicians in the office, as well as the general public, to follow conversion progress throughout the city.
After contractors change an HPS light fixture to LED, they select the corresponding light on the map and update its conversion status (including date and serial number for warranty purposes). The procedure developed reduces the need for paper copies and provides more information directly from the installer. The installation process allows the city to track 14 material needs and update billing accurately and precisely. The tracking of the cost of materials and labor can help enable the prediction of future maintenance costs. Contractors can make notes in an accompanying comment field, providing supplementary observations about pole or circuit repairs needed, or lights that have been mis-mapped or are missing altogether. PBOT rates the overall experience using GIS mapping software and off the shelf technology as extremely positive. PBOT reports that the associated savings have been substantial. PBOT overwhelmingly recommends the process to other public agencies.
The report noted that upgrading Portland’s street lights to LED luminaires were more complicated and lengthy than PBOT originally envisioned. Several issues and circumstances arose during the intended purchase and conversion processes that increased both their cost and the amount of time to complete. The report noted that project participants required patience and persistence in large measure, along with collaborative working relationships with the other parties involved. Ultimately, the city of Portland and its residents are largely pleased with the results. Other public agencies interested in pursuing similar efforts should anticipate similar issues and requirements that are both expected and unexpected. The city reportedly found that the value of the project in terms of projected savings is well worth the effort.
