Minneapolis approach to LED lighting
The City has been moving forward with converting the city’s street lighting to LED (Light Emitting Diode) light sources. This conversion meets the following objectives:
- Alignment with the City of Minneapolis goals and Clean Energy Partnership
- Improved lighting quality which includes color, visibility, dark skies, less light trespass, etc.
- Environmental benefits such as lower energy use, less CO2, etc.
- Lower costs related to less wattage/electricity, less maintenance due to longer fixture life, etc.
Thus, Public Works has developed, tested and began converting to LED lights in 2015.
Read the street lighting policy
Minneapolis street lighting policy (page 7)
This document shows the three styles of LED full cut-off fixtures mounted on city metal poles. The higher wattage street lights (300W converted to 93W LED) were chosen as the first phase due to their greatest benefit and quickest return on investment. This first phase began in late 2015 with existing high wattage street lights on major arterial corridors and in downtown.
Detailed information about the first phase, its roll-out and frequently as questions is presented in the LED street lighting update
As of July 2016, Public Works is in the process of converting Zone 1 and Zone 2 simultaneously. Over 950 LED lights have been converted to date and another 500+ will be converted in the second half of 2016.
In addition to the first phase LED conversion program, Public Works is replacing old lighting with LED lighting when the opportunity presents itself through routine replacements due to damage/wrecks, street reconstruction projects, and other street lighting projects. Subsequent phases for LED conversion are under discussion and Public Works is analyzing the low wattage lights mounted on low/mid-level metal poles and wood poles.
More attention has recently been focused on LED street lighting and encompasses two topics – a) light trespass/dark skies/glare, and b) color temperature. Each of these topics are summarized below.
Light trespass, dark skies and glare
As LED lighting has become the industry standard, Public Works has tested many products and requires street lights that focus light only where it is needed. The adopted Street Light Policy standard for newly installed street lighting requires full cutoff fixtures that do not allow any up lighting. This complies with dark skies guidance and reduces light pollution and trespass. In addition, these full cutoff fixtures, in combination with the new LED technology, allow the light to be further directed only where it is needed. Thus, further reductions in light trespass and glare for pedestrians, bicyclists, and motorists.
Does color temperature have an impact? This topic is an emerging issue. However, at this time there is not complete research on this concern or its implications.
For the public trying to understand the issue of color temperature, it is easy to relate it to the blue light color emitted from TVs, cellphones, LEDs in home lighting, etc. We are hearing the same concerns about those devices/lights as with LED street lights regarding the amount of blue light emitted. Blue light (which is generally defined by a wavelength range in the light spectrum) is not unique to street lights. There is blue light emitted from other outdoor sources including vehicle headlights, moonlight, and sunlight. Even the older style street lights (high pressure sodium, metal halide and fluorescents) also contain some blue light.
Public Works became aware of the color temperature issue in late 2015. Since then we have continued to monitor this issue and engaged in conversations with Xcel Energy. For those interested in more detail on this topic, please see the links below.
To be proactive, the City of Minneapolis is conducting its own test. Public Works has identified a street light fixture that emits a “warmer with a more yellow/orange appearance, less blue” light color. These LED lights are generally less energy efficient and do have some effect on how colors are perceived. The fixture will be installed and tested on Plymouth Avenue between Lyndale Ave N and 2nd St N.
Overall, Public Works will continue to monitor the changing technology and associated LED research. As we learn more, we will update this web page and as needed our street light policy.
If you have questions, please contact us
Other sources for LED lighting information
- SSL Postings U.S. Department of Energy
- Municipal Solid-State Street Lighting Consortium
- Seattle LED Adaptive Lighting Study
- American Medical Association (AMA)
The City of Minneapolis Street Light Policy was updated by Public Works staff and adopted by the City Council in 2015.
The City of Minneapolis Street Lighting Policy and Program will support the City's efforts around livable communities and urban development. Appropriate lighting levels are a security and safety issue.
A policy will help to ensure that all areas of Minneapolis receive consistent treatment, and will give clear guidance to elected officials, residents, developers, and the Department of Public Works on all aspects of street lighting system installation and maintenance.
The policy and program addresses a number of issues including
- Clarification of internal practices
- Equalization of independent initiatives
- Areas with limited lighting
- Improvement of lighting in pedestrian areas
- Safety concerns
- A simplified process for installation
- Technical efficiencies and sustainability
The street lighting policy objectives are
- Maximizing the quality, sustainability, and visibility of the street lighting system
- Contributing to added comfort and safety for pedestrians, bicyclist, transit users, and motorist
- Creating a consistent and cohesive lighting system based in place-type characteristics throughout the City of Minneapolis
- Providing pole and fixture options that are aesthetically pleasing and high quality
- Providing clear guidance on expected installation methods, procedures and maintenance service levels
- Creating a system that is cost efficient, easy to operate, and maintainable
- Addressing costs to the City’s capital, maintenance, and operations budgets