Street Light Replacement FAQs
- Why are the lights being replaced?
- Cost savings:
Most of the City’s streetlights are very old and inefficient. The City spends 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 our existing street lights!
New LED lights allow much greater control over where light shines. This will allow 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.
- Cost savings:
- It looks like there are cobrahead fixtures in my neighborhood but they are NOT listed on the installation schedule. Why?
There are some street lights that may appear to be a cobra or shoe box style that are 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 is out of scope for this project. It’s also important to note that the City has already installed several hundred LED’s. This project won’t replace existing LED fixtures.
- What are the old street lights being 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 is this project going to cost?
The capital cost to support this project is estimated at $5.5 million, which includes materials and installation and Washington State sales tax. This project came in $2 million under budget.
- How is this being funded?
To enable the City of Tacoma to upgrade the street lights through this initiative, TPU created a special “Street Light” rate. This rate applies specifically to LED street light 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 will the project be completed?
Installation is scheduled to begin in Q4 of 2017 and 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 street lights near my home or business will be replaced?
- 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 street lights (https://www.ama-assn.org/ama-adopts-guidance-reduce-harm-high-intensity-street-lights).
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 street light 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.
- Will the City be installing 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 will allow 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