Seattle-Based Community-Owned Utility Invests in LED Streetlight Upgrade to Improve Safety and Efficiency

Sun Valley Lighting Gothic-Style LEDs Outperform Competition in Five-Year Pilot Study

OPERATING AS THE LONGEST RUNNING residential and business conservation program in the country, Seattle City Light continues to invest in energy efficiency. Seattle City Light is a community-owned, not-for-profit utility that provides carbon-neutral electricity that is generated primarily from carbon-free hydropower. Its focus is on providing affordable, reliable, and environmentally responsible energy services every day to power the homes, businesses, and communities it serves.

Recently, the not-for-profit utility completed a pilot program to improve customer safety, reduce carbon emissions and conserve resources by testing LED streetlight fixtures in Seattle’s Windermere neighborhood.

The previous high-pressure sodium (HPS) streetlights were aging and due for replacement. Seattle City Light wanted to replace 300 Gothic style HPS fixtures with efficient, environmentally friendly and functional LED fixtures. Since not all LEDs are the same, the pilot program involved testing five fixtures within the Windermere neighborhood to select the most efficient lighting solution. The new fixtures were evaluated for appearance, historical integrity and light levels.

The objective of the new streetlights was to improve the quality of lighting as a means of enhancing both pedestrian and traffic safety. Seattle City Light also wanted to reduce greenhouse gas emissions with the switch to LEDs. Since LEDs are more efficient and perform longer than HPS fixtures, Seattle City Light calculated that changing the streetlights would reduce approximately 20,000 tons of carbon emissions each year as the result of fewer service vehicle trips needed to repair or replace the lighting fixtures.

The pilot program covered five years of analysis to determine the best lighting solution for the community. The key pilot project decision-makers included lighting designers, city officials, standards engineers, program managers, installers, maintenance crews and, most importantly, the neighborhood association which would live under the fixtures for many years. In fact, the pilot program provided an opportunity for community feedback that impacted which fixture would be chosen.

Energy Efficient, Environmentally Friendly

After an extensive evaluation, Seattle City Light specified approximately 300 LCC Series Gothic style energy efficient, environmentally friendly and functional LED fixtures from Sun Valley Lighting in Palmdale California.

Kevin Gorman, Streetlight LED Conversion Program Manager for Seattle City Light, said, “We selected the LCC Series based on three major factors. First, the fixtures maintained the gothic style to fit within neighborhood aesthetics. Second, we found that the LCC Series provided superior LED efficiency and light control during the pilot program. And finally, the fixtures are made by a reliable and trusted manufacturer to ensure the quality of the streetlights.”

The LCC Series fixtures have micro-reflectors mounted around each LED to control the raw light output. The engineered LED optical components are uniquely aimed horizontally and vertically and combined to produce highly efficient light distributions. Clear-patterned diffusing lenses were also used to minimize glare.

“We found that utilizing a Type II distribution pattern with Sun Valley Lighting’s proprietary LED Power Array™ 2 and glass refractor produced an even light distribution over the desired illumination zone of the neighborhood streets and sidewalks. We also utilized a house side shield to ensure there was minimal light trespass onto private property,” Gorman added.

The streetlights include 2700K CCT LED chips to deliver a warmer and more environmentally friendly lighting solution for the Windermere neighborhood and residents of Seattle. Also, the LCC Series fixtures incorporated a 7 pin NEMA photocell receptacle and 0-10v dimmable power supply to allow the new streetlights to be compliant with an upcoming wireless control system implementation.

The LCC Series uses constant current LED drivers that efficiently operate on input voltages from 120- 277VAC, 50/60hz. The LED driver is mechanically fastened to a retaining bracket. The driver has a minimum 4KV of internal surge protection with a 10KV and 20KV surge protector optional.

Built to Perform

The fixtures have high-Impact clear acrylic diffusing lenses with durable corrosion-resistant cast aluminum housing. Their tops are hinged for access to the LED compartment and wiring is accomplished through toolless access to a terminal block compartment. All hardware is stainless steel.

Gorman added, “The utility crews really appreciated the ease of installation with the new access door which allows easy reach to the utility-grade terminal block and integrated surge suppressor.”

Built to last for many years, the LCC Series fixtures have a polyester powder coat finish that incorporates a four-step prewash process to pretreat the metal surface for maximum coating adhesion. The top coat is baked at 400°F for maximum hardness and exterior durability to ensure better color retention and a longer performance life.

Gorman additionally noted that Sun Valley Lighting and their local representative, Jeremy Michel from ERW Lighting + Controls, was in-step with stakeholder requests throughout the pilot program and responded thoroughly, often exceeding expectations with expedience and sometimes offering better ideas than what were originally presented.

“The overall result is a beautiful, energy-efficient, gothic style appearance with precise directional lighting that residents will appreciate during the night and day for many years to come,” said Gorman.