Why were the streetlights replaced?

• Cost savings: Most of the City’s streetlights were very old and inefficient.  The City spent almost $1 million every year just on electricity for street lights and traffic signals. These new LED fixtures will significantly lower our costs because they only use 25% - 35% of the power used by the older street lights.
  
  
• Safety: New LED lights allow much greater control over where light shines.  This allows us to reduce glare, lower light pollution and better distribute light to maximize safety.
  
  
• Energy Savings: We estimate this project will save 11,500 MWh per year and the 15-year Net Present Value (NPV) is $5.7 million. 
  
  
• It looks like there are cobrahead fixtures in my neighborhood but they were not replaced.  Why?
  There are some streetlights that may appear to be a cobra or shoe box style that was not scheduled for replacement. While they may look the same, these lights are actually structurally different and require additional retrofitting before they can be upgraded to LED. That was out of scope for this project. This project did not replace existing LED fixtures.
  
  
• What were the old street lights replaced with?
  Energy efficient 3000K LEDs were installed in residential and local areas. For higher speed arterial streets, 4000K LED fixtures were installed to ensure adequate safety. 

How much did this project cost?
The capital cost to support this project was estimated at $5.5 million, which included materials and installation and Washington State sales tax. This project came in $2 million dollars under budget.

How was this project funded?
To enable the City of Tacoma to upgrade the streetlights through this initiative, TPU created a special “Streetlight” rate.

This rate applies specifically to LED streetlight fixtures and includes all capital recovery costs, electricity and administration of this project.   The 15-year net present value (NPV) in savings to the city is estimated to be $5.7 million and 11,500 MWh savings per year.

When was the project completed?
Installation began in December of 2017 and was projected to be completed by the end of 2018. The project finished three months ahead of schedule in October 2018.

How do I know if the streetlights near my home or business were replaced?

An interactive map with the installation schedule by neighborhood is available to view. If you are unable to access the map for any reason, a PDF of the map and schedule is also available. 

Are LED lights harmful to my health or the environment?
Replacing old, high-pressure sodium lights with new LED fixtures should have no negative impact on health or the environment.  In fact, LED lights offer significant benefits including reduced energy use and less light-trespass.

I read that the American Medical Association (AMA) issued a report that excessive blue light emitted by LEDs is harmful to health and the environment.
In June 2016, the American Medical Association (AMA) published an article on the potential environmental and health hazards associated with LED streetlights. 

The AMA article’s focus evaluated early LED installations with respect to glare and light trespass (light spreading to unintended areas), the potential impacts on human health and the environment and how best to minimize those impacts.  The AMA commended the energy efficiency and effectiveness of LED technology, but also urged cities to minimize the amount of blue-rich outside lighting and recommended the use of LEDs with a color temperature equal to or less than 3000K to minimize the amount of glare. 

The report failed to consider some of the significant benefits associated with various higher temperature lights in certain situations.  A study in Seattle documented how light color temperature can affect how far in advance drivers can detect objects.  That study found the best color temperature for night time object detection is around 4000K, approximately the same color temperature as moonlight.

• Glare reduction – LED technology has significantly improved since the early installations used in the AMA study.  New LED technology provides much greater control over glare and lighting than early installations including how much, where and when light is dispersed).
• Night vision – For high speed traffic areas, industry research suggests 3000K is insufficient to support optimal safety for drivers and pedestrians.  For higher speed areas, 4000K LED lighting improves object detection by 1.5 times that of 3000K fixtures.
• Quantity of blue light – every streetlight emits some degree of blue light.  While the percentage of blue light emitted is higher in the new LED fixtures, the intensity is less than existing fixtures.  Normalized by intensity, the 4000K arterial LEDs will emit 12 – 17% less blue light than our existing high-pressure sodium fixtures.

LEDs provide the greatest ability to control where and when light is dispersed, how much is dispersed and at the optimal spectrum– more than any other technology available on the market. 

Did the City install any LEDs that go against the AMA recommendations?

3000K LEDs were installed in all residential and local areas, which comply with the AMA recommendations.  In higher speed arterial streets, Public Works will be installing 4000K fixtures to ensure adequate safety.  After extensive research, Public Works found that 3000K lighting in high traffic areas did not meet minimal safety requirements for traffic and pedestrians.  It was determined that 4000K LED lights provide optimal safety in high-speed arterials.  This allows the City to:

• Minimize glare through design and fixture
• Increase night visibility and object detection at a distance
• Provide lighting that emits less “blue light” than existing high-pressure sodium fixtures

Less light pollution: 

• The dim-ability of LED technology allows us to control streetlight systems to only provide the level of illumination needed at any given time, which is nearly impossible with conventional streetlighting.  
• LEDs allow for a high degree of control over where the light is directed, as opposed to conventional street lamps that shine light in all directions.
• Many of the former lights broadcasted light into the sky.  This type of light, called up-lighting, provided no benefit for streetlights that are 30 – 40 feet high and, in fact, actually creates visual problems for nocturnal animals.

Improved visibility:

• LEDs provide greater control over the light distribution, creating more consistent light levels where needed.  This minimizes the amount of blue light emitted reducing glare.
• LED lighting allows greater visibility at a distance for drivers, creating an extra safety margin by providing between 1.5 – 2 times further coverage than existing streetlights.
• Because the new fixtures produce less total light, the new LED lights will actually emit less “blue light” than our existing high-pressure sodium light fixtures.

Less energy:

• LEDs use 50 – 65% less energy than the former fixtures (high-pressure, sodium lights)

Lower costs:

• Lower materials costs - LEDs are more efficient and last much longer than the former conventional streetlight lamps.
• Lower utility costs- LEDs require less energy, thereby lowering monthly electricity costs
• Lower maintenance costs - Fewer replacements means lower overall maintenance costs.

Improved safety and security: 

• Fewer outages - longer life equipment means fewer streetlight outages, improving both safety and security.

• Department of Energy - Street Lighting and Blue Light – Frequently Asked Questions
• Seattle Lighting Study