LED Streetlights

Sustainability Director

Brian Blackmon
bblackmon@knoxvilletn.gov
(865) 215-4430

400 Main St., Room 598
Knoxville, TN 37902

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Retrofitting streetlights with LED fixturesHistorically, the City has spent approximately $4 million each year to cover the energy, operations, and maintenance costs of streetlights owned by KUB. About half of these costs paid for electricity service, while half went to operations and maintenance.

From 2017-2019, the City partnered with KUB and Siemens to transition ownership and complete a major retrofit of approximately 29,500 streetlights with highly-efficient LEDs.

The previous streetlights relied on high-pressure sodium (HPS) technology, which wastes a lot of energy in the form of heat. In contrast, light-emitting diode (LED) technology is a highly-efficient process that uses semiconductors to convert electricity into light. Learn more about LED and other efficient lighting technologies at DOE’s Energy Saver website.

The project was completed in 2019 and provides multiple benefits to both City government and the public:
  • Improve quality of light, visibility, and safety throughout the City
    LEDs provide a crisp, bright light that improves visibility and color rendition, making it easier for drivers to spot pedestrians and obstructions in the roadway. The City’s new 3000 Kelvin lights have a warm white color, similar to an incandescent bulb. This “color temperature” aligns with recommendations from groups such as the International Dark Sky Alliance and American Medical Association to minimize impacts on nocturnal wildlife, reduce glare and sky glow, and improve nightscapes. Most of the City’s new lights are “full cutoff” fixtures that direct light downward to illuminate the street and reduce gaps in lighting, dangerous glare to drivers, and light directed onto homes and properties. In rare cases where light from the new LEDs is intrusive to private property, residents can request the City to evaluate the fixture to see if it fits criteria to have a shield installed.
  • Reduce energy use, utility costs, and emissions
    LEDs use 65% less energy than previous bulbs, significantly reducing utility costs and greenhouse gas emissions.
  • Reduce maintenance costs
    LEDs have longer lifespans and lower failure rates than HPS lights. The City’s new LED fixtures are warrantied for 10 years and guaranteed to at least 70% of their light output for 100,000 hours (about 20 years). As a result, costs associated with ongoing maintenance is significantly reduced.
  • Future-Proof Technology
    The City’s new LED lights have built-in 7-pin photocells that provide extra “sockets” to enable innovative technologies such as controls, should that become desirable and cost-effective in the future. 


Project Timeline


January 2017: RFP issued
Summer 2017: Design Phase, Pilot Installations, & Stakeholder Engagement
April 2018: City assumed ownership from KUB
Summer 2018 – December 2019: LED fixtures installed on approximately 29,500 streetlights citywide


City Investment

One of the City’s primary objectives for the project was that all upfront costs would be offset within 10 years by cumulative savings from reduced energy and maintenance costs for the lights.

The City estimated that the total cost of the project would be approximately $15.8 million, including (but not limited to) labor, materials, supplies, equipment, facilities, disposal, retrofit design, and processing for all utility rebates. 

The City took ownership of streetlight infrastructure from KUB in April 2018. This transfer in ownership eliminated KUB Facilities Charges (approximately $2.3 million annually) and shifted maintenance responsibilities to the City. In addition to gaining the ability to control maintenance costs, the City anticipated maintenance costs to decrease by about 50% due to the long lifespan and low failure rate of LED lights. 

Finally, the City anticipated significant reduction in energy consumption and costs due to the high efficiency of LEDs.


Results


The project was completed in December 2019, and the City has already seen significant savings and benefits. 

Decrease in Energy Use and Utility Costs: In 2020, the City’s streetlights consumed 10,986,370 kWh (a 56% decrease from prior years) and cost $871,291 in utilities (a 76% decrease from prior years).

Streetlight Energy Streetlight Energy Cost


City vs KUB Lights

The City and KUB both operate lights in the City’s territory. Both 3-1-1 and KUB can determine whether a streetlight is owned by the City or KUB.

 CITY LIGHT
City Light
KUB LIGHT
KUB Light


The City owns approximately 30,000 streetlights, primarily located on publicly-owned streets and right-of-ways. Most City streetlights have a metal tag with a 4-6 digit number (see image above at left). Questions/comments about City streetlights lights can be directed to the City’s 3-1-1 Center for Service Innovation.

KUB maintains a large network of Outdoor Private Lights, primarily used in customer-owned locations such as backyards, playgrounds, or driveways. Sometimes called “Light Watchmen,” most KUB Outdoor Private Lights have a metal tag with a 9-digit number preceded by “LW,” (see image above at right). Questions/comments about KUB Outdoor Private Lights can be directed to KUB’s Customer Service.


Report a Problem

If you find a streetlight that is damaged or not working, please confirm that streetlight is owned by the City (see above) and then submit a 3-1-1 Streetlight Outage Request Form