LED lights to increase efficiency, light pollution; City starting street light replacement project

Staff Writer

The above graphic marks all of Montrose's 1,900 street lights. The red dots show those lights that have already been upgraded to LEDs, while the blue and yellow lights show older fixtures such as high pressure sodium or mercury vapor. (Graphic from April 17 City Council work session slideshow)

Last week Montrose City Council approved $110,000 for the first part of a street light upgrade project. Once completed, this project will save the city thousands of dollars per year in energy costs, but will it increase the city's light pollution?

Many of Montrose's street lights are currently high pressure sodium or mercury vapor fixtures, most of which were originally installed around 70 years ago. This project aims to switch all of these fixtures out with more efficient LED fixtures.

"Once all of the lights are changed to an LED this would result in about $200,000 per year less in energy costs to the city," said Public Works Director Jim Scheid at the May 2 city council meeting where the first round of installations for this project was approved.

Currently, the city has about 1,900 street lights total. Over the last decade or so nearly 500 have already been converted to LED.

The $110,000 approved at last week's meeting will allow for the replacement of about 350 to 400 more street lights.

"Return on investment for the city for buying the fixtures up front is about 2.3 years, so that's very short considering the amount we spend on electrical costs," said Scheid. "So that means we can buy the fixture this year, and the amount we will save in energy at each fixture over the next 2.3 years will pay for what we spent on that fixture."

The cost to replace all of Montrose's street lights to LED is $440,000 total. This street light upgrade project expects to take about four years to complete, with $110,000 being spent each year until finished.

The funds for this year's upgrades were included in the city's 2023 budget, although the continuation of this project depends on what funding is available for future years.

These initial budget reasons, as well as the expected manpower it would take to replace these lights, are why the city is not choosing to replace all street lights in 2023, explained Scheid to the council.

Former mayor and current city councilor, Dave Frank, revealed that although the city pays for the electricity to keep Montrose's streets lit, "DMEA owns the street lights, so this is a real benefit to the city ‘cause it's gonna save us a lot of money shifting to the LED lights."

Since Delta-Montrose Electric Association (DMEA) owns the street lights, the city also approved a Memorandum of Understanding between it and the electric cooperative last Tuesday.

DMEA will install the LED fixtures for the approved amount while the city pays for these replacements.

"DMEA, as it currently stands, would change the existing mercury vapor and high pressure sodium fixtures to an LED as they burn out," said Scheid. "Which we’ve seen those are very long lasting fixtures and that could be 20 plus years."

The unknown rate at which these fixtures will burn out, as well as the estimate that it could take a couple decades to do so, would affect the city's return on investment.

While it will replace all street lights, this project does not encompass adding any street lights around town. It also does not include the decorative fixtures found at places like Main Street. Those lights are city owned.

Renewable energy for the town's street lights is not the best route, either.

Scheid explained to city council at an April 17 work session that the city has one solar street light, remarking the challenges and cost to run power to it.

"We’re still monitoring," continued Scheid on testing solar energy in high-use areas like intersections where it is important that the light there is reliable. "I think the best use of our solar lights is on the trail system."

These LEDs are found to be more energy efficient, and different street light types will be used to mark different street types. "Certain minor arterials and major arterials would be lit differently than residential roads, helping to organize our street network," said Scheid.

New lights in dark skies

This project intends to use shielded lighting and lower light levels where possible along with utilizing light that serves a purpose, which all meet certain principles of the International Dark-Sky Association's (IDA) Dark Skies Responsible Outdoor Lighting.

While these efforts will certainly reduce light pollution, Scheid emphasized that "This project is not intended to achieve a dark sky community status."

Aaron Watson, board chair for DarkSky Colorado, stated "street lights can really have a big impact" when it comes to a particular town's light pollution.

Along with listing shielding and color temperature, one thing Watson asks towns like Montrose to consider are adaptive controls such as dimmers, timers and motion sensors that regulate light so that street lights are used more when needed and less when they aren't.

Some dimmers, said Watson, can dim lights down 30%. IDA has seen towns like Tucson use adaptive controls with great results for their efforts.

The city can also lower the height of street poles in residential and pedestrian areas to reduce impact.

Another concern that Watson warns of is just how bright LEDs are.

More and more cities across the U.S. are switching to LED street lights. While they are great at saving energy, this "LED revolution," as Watson puts it, has increased the nation's light pollution.

A study published in the journal "Science" earlier this year found that the average night sky across the globe brightened by 9.6% per year from 2011 to 2022.

Watson remarked that this increase is mainly due to LEDs, urging "people (to) be aware that these lights have a harmful effect beyond where you want to use them" and that cities might should "put a brake on these LEDs."

Why should Montrose consider becoming a certified dark sky community?

Well, many of our neighbors already are, including Ridgway and Black Canyon of the Gunnison National Park. Light pollution does not affect only those who live within Montrose County; the sky glow from Montrose can be seen from these communities nearby who are doing their part to reduce light pollution.

Further, becoming a dark sky community would mean the return of great night sky views, and Watson says it is "totally possible to get that view back."

Towns like Flagstaff — with a population almost quadruple the size of Montrose's — have attained the return of such views.

According to Watson, there is funding available from both state and federal sources to help promote such efforts.

You can also find information on IDA's light monitor grant program at https://www.darksky.org/light-monitor-grant-program/, which provides monitors that help collect data on light pollution.

Watson reminded that taking "extra time up front" when it comes to reducing light pollution pays off in the end.

Staff Writer

Rhiannon Bergman is a staff writer for the Montrose Daily Press.

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