Tri-State embraces next generation lighting

Cree Lighting demonstrates its LED fixtures at a trade show. In the top photo, the display is lit with CFLs. The bottom is the same display lit with LEDs in the company's LR6 downlight fixtures. The pictures are unretouched. (Photos by Cree Lighting)

Editor's note: We at Energy Services are aware that lighting technology is changing rapidly, particularly in the area of light-emitting diodes (LED). There is still much to be learned about best practices, economics and appropriate applications.  This article is intended to encourage discussion about the pros and cons of different types of energy-efficient lighting systems.  For another point of view, see In my opinion: Look at all options, issues when upgrading lighting.  Energy Services Bulletin, Mike McCoy and Ryan Holl look forward to hearing your comments.

Leading by example is a good way to get people to try something new, so Tri-State Generation and Transmission Association is upgrading the lighting at its headquarters with light-emitting diodes (LEDs), indoors and out. 

The board of directors of the Westminster, Colo.-based G&T recently approved funding for LED demonstration projects for cities in their members' territories. "If we want our members to adopt LEDs, they have to be able to examine the fixtures, see the lighting quality for themselves and talk to facility managers who have experience with the technology," said Mike McCoy, senior engineer for key accounts at Tri-State. "This demonstration will give them a place where they can do that."

Fewer lights, better lighting

The project began with two conference rooms—a smaller facility, and Tri-State's main conference room.  McCoy explained, "We wanted to get the retrofit done for the January meeting of the board of directors."

The conference rooms were lit with a combination of downlights that consumed 75 watts each and 2x2 fluorescents that used either 23 watts or 40 watts depending on the tubes. The small conference room had four 2x2 fluorescents and eight downlights, while the big room had eight 2x2s and 19 downlights. Replacing all the lights with 12-watt LEDs reduced the two rooms' energy consumption by more than half when all the lights were in use.

Some people worried that the LEDs wouldn't be bright enough. "So we brought them into the room and turned on the lights," McCoy recalled. "It was so bright, we were able to take down two 2x2s and 3 downlights. That cut the energy use by about two-thirds. We may be able to take down more lights."

The fixtures chosen for the indoor retrofit are also dimmable down to 5 percent. McCoy noted, however, "That's such a small load, the dimmer thinks nothing is connected."

Low maintenance improves payback

Outdoors, the conversion of 34 400-watt metal halide parking lot lights to 153-watt LED fixtures is underway, and should be completed by April. The project places Tri-State in the ranks of Anchorage, Ak., Ann Arbor, Mich., and other municipalities that are discovering savings in more efficient street lighting.

A lighting engineer from vendor Cree LED Lighting worked with McCoy to measure the parking lot lighting and evaluate Tri-State's maintenance records. "A vendor should have computer modeling software to help customers look at the whole picture before making a decision," said McCoy.

The big picture should take into account LED lighting levels and low annual maintenance—considerations that go a long way to offset high first costs. Not only will the lights in Tri-State's parking lot use less energy, fewer lights may provide the same light level so fewer will need to be on at a time. The instant on-off capability of LEDs means that the lights could be placed on motion sensors, or turned on only when needed between 10 p.m. and 4 a.m. "If security needs to see what's going on in an area, they turn on the LED and get full light level right away," McCoy said. "By the time a metal halide reached full intensity, an intruder would be miles away."

He anticipates saving a large portion of the $800 Tri-State spends annually to maintain its lot lighting for a total payback of about four years. Labor savings play a large part in street and traffic lighting projects that boast paybacks of as little as two to three years. "City lights are usually on for about twice the amount of time as our parking lot lights," McCoy noted.

Taking an even longer view, he pointed out that LEDs depreciate rather than burn out, so older lights could be moved to light an area that doesn’t need as high a light level. "But it will take about 25 years for our parking lot lights to depreciate by 30 percent, so someone else will be making that decision."

Slow road to adoption

Despite LEDs' long life, gross efficiency estimated at almost double that of CFLs and construction of non-toxic, recyclable material, cities and facilities have not rushed to install them. The technology is still very expensive and not suited to all applications. McCoy, a former lighting engineer, admits that if cost is the greatest consideration, the latest generation of fluorescent lighting is the way to go. "But do your homework—some LED applications, like refrigeration lighting, are already competitive and others will be soon," he said.

McCoy added that demonstrations like Tri-State's are a necessary step toward wider commercialization. "LEDs work differently than the other lighting technologies currently available. We need to test them in real world settings to learn their capabilities and limitations, to figure out the best uses for them," he said.

Another challenge to retrofit projects is finding good quality fixtures, essential to the light's performance and to the success of the installation. Energy Star now rates commercial LED lighting, but compared to other products, the list of LED partners is limited, both in number and applications.

McCoy chose another strategy for keeping up with the rapidly-changing technology. "I spent time getting to know vendor representatives so they invited me to local presentations to see new units," he said.

Through his contacts, McCoy learned of the LR6, a new LED fixture manufactured by LED Lighting Fixtures, Inc. (LLF). The downlight combines 42 LEDs per fixture in a proprietary mix of colors to deliver more light per watt and better color rendering than most CFLs. LLF used Cree LEDs to demonstrate its product at the International GreenBuild Conference in 2007, where it was named one of the green products of the year. "Cree was so impressed, it bought LLF," recalled McCoy.

Opportunity for Tri-State members

McCoy and the Tri-State board were also impressed—enough to install the units at the headquarters building and to approve funding for a demonstration program. The G&T is encouraging cities served by its member co-ops to replace conventional street lighting with LEDs by offering to pay one-third of the installation cost. The co-op and the city would supply the balance of the funding. The cities of Ouray, Telluride and Durango, Colo., have expressed interest in LED street lights, and Tri-State is accepting proposals from members for retrofit projects. 

Lighting is considered the "low-hanging fruit" of energy efficiency, and Tri-State's two-year-old CFL program has helped to put 125,000 compact fluorescent lights in consumers' homes. McCoy sees the new LED program as the next logical step. "Eventually, LEDs will replace fluorescents. The technology potentially has so much more to offer than current lighting systems," he said. "Tri-State is demonstrating LEDs now so that our members will ready to help their communities and customers take advantage of the most efficient lighting available."

Resources

Tri-State Generation and Transmission Association

Cree LED Lighting

Energy Star LED partners

International GreenBuild Conference

People

Energy Services Bulletin Editor

Mike McCoy

Ryan Holl

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