Colorado demonstration shows streetlight retrofit a winner

By switching out their old streetlights, the cities of Sedgwick and FountainRedirecting to a non-government site, Colo., cut their electric bills and improved the quality of municipal lighting. Even better, they were able to offset the cost of the retrofits through grants and partnerships.

A roadway in Fountain, Colo., lit by conventional  mercury vapor streetlights. (Photo by Fountain, Colo.)
A roadway in Fountain, Colo., lit by conventional mercury vapor streetlights. (Photo by Fountain, Colo.)

The opportunity presented itself in 2010, when the Colorado Governor’s Energy OfficeRedirecting to a non-government site (GEO) announced its Street Lighting Demonstration Grant Program. Qualifying communities would receive funding to pay for the installation of high-efficiency streetlights, and then measure their energy and dollar savings to track the return on investment.

GEO chose Sedgwick, in the northeast corner of the state and Fountain, a Western customer located south of Colorado Springs, to receive the grants. Each town would replace inefficient mercury vapor fixtures with light-emitting diode (LED) technology, and provide GEO with data on the streetlights’ performance.

Complete overhaul
Highline Electric AssociationRedirecting to a non-government site, Sedgwick’s power provider, applied for a grant with an eye on helping its municipal customer while demonstrating new technology. “Like a lot of towns in this part of the state, Sedgwick is very small and was struggling even before the recession,” said Highline General Manager Mark Farnsworth. “Any measure that significantly reduces the town’s operating costs is going to make a big difference.”

Technicians from the cooperative replaced 53 175-watt mercury vapor lights with a combination of 50-watt Clearlight Beacon bulbs and 40-watt Clearlight EcoSpot bulbs. The installation included 11 complete fixtures along two major thoroughfares with 100-watt Evolve LED roadway lighting.

After Fountain, Colo., installed energy-efficient LED streetlights, energy use by the replaced units dropped more than 50 percent, roadway lighting improved and maintenance crews anticipated fewer lamp replacements. (Photo by Fountain, Colo.)
After Fountain, Colo., installed energy-efficient LED streetlights, energy use by the replaced units dropped more than 50 percent, roadway lighting improved and maintenance crews anticipated fewer lamp replacements. (Photo by Fountain, Colo.)

In addition to in-kind labor, Highline contributed $1,140.00 to the project. Tri-State Generation and Transmission AssociationRedirecting to a non-government site, added $2,524.13 in efficiency incentives, so the upgrade cost Sedgwick’s 190 residents nothing. The retrofit lowered Sedgwick’s previous annual cost for street lighting from $4,877.49 to $1,762.29. If the town had paid all costs and received Tri-State’s efficiency rebate, its simple payback would be 3.1 years.

Targeted replacement
A city of 27,000 residents with its own municipal utility, Fountain chose key areas for improvement, rather than completely replacing its streetlights.

In the space around the Fountain City Hall, 24 140-watt LED fixtures replaced the same number of mercury vapor lights. “But we drove them harder to see how they worked, and got lighting equivalent to 400-watt mercury vapor fixtures,” said Fountain Electric Superintendent Jerry Early.

At a busy intersection, the city installed another 24 LEDs, this time 70-watt bulbs, as well as 14 30-watt decorative LEDs, to replace 100-watt high-pressure sodium (HPS) lights. The measured reduction in energy use for the two areas totaled 57 percent.

The Security Water and Sanitation DistrictsRedirecting to a non-government site in Colorado Springs contributed funding to the retrofit. “They were super to work with,” noted Early.

In a separate project funded by El Paso County, the lighting in a blighted area got a facelift with 77 52-watt fixtures, some new, replacing 175-watt mercury vapor lights. The utility is metering some of those lights individually to measure the energy use.

Weigh all the factors
LED technology offers many advantages in street lighting applications. Not only do the lamps use much less energy, they don’t get as hot as conventional bulbs, contain harmful compounds or attract insects. Their lifespan of up to 100,000 hours is more than twice that of new HPS bulbs, which saves money on replacement. “The lighting quality and the Kelvin rating are good,” Early pointed out. “I’m a fan.”

However, LED fixtures are still expensive compared to the almost-as-efficient HPS bulbs, which fit into standard fixtures. The performance of LEDs in cold weather was a problem that has been improved in newer bulbs. And the cost continues to come down, so it seems to have been in the best interest of utilities and municipalities to wait on adopting this energy-efficient technology.

See what rebates are available from utility, state and Federal programs for streetlight retrofits. And keep in mind that lighting technology has changed even in the two short years since Sedgwick and Fountain completed their projects. “It’s worth checking into,” stated Farnsworth. “LED lighting may be an excellent investment for your town.”

Take the DOE streetlight survey
Because streetlights use a lot of energy and cost a lot to maintain, they are also a potential source of big savings for cities. To get an accurate picture of those costs and possible solutions, the Department of Energy’s Municipal Solid-State Street Lighting Consortium (MSSLC) has launched a nationwide survey of roadway lightingRedirecting to a non-government site.

The MSSLC is inviting municipalities, utilities and other system owners to help develop a current inventory of street lighting. The goal of the inventory project is to:

  • Establish a more reliable number of the nation’s streetlight types
  • Identify street lighting ownership models, e.g. what is the source of funding and what entity collects the fees?
  • Determine how much energy the nation’s streetlights consume 
  • Provide a clear picture of what it costs to operate and maintain our streetlights

The inventory divides publicly funded streetlights into roadway lights and area lights. Roadway lights are subdivided into streetlights and highway lights, and include those that illuminate local and collector roads and interstates, freeways and expressways. Area lights encompass lights in public places and walkways, such as parks, public parking lots, outdoor areas and landscapes.

The survey will be active throughout the summer, and possibly into the fall. Don’t miss this opportunity to participate in developing policies to reduce the energy and economic cost of street lighting.