So last year, Mr. Gauthier replaced all his older lights with 140 costlier light-emitting diode fixtures, or LEDs, which produce three times as much light on the ice for each watt of energy and last far longer — an investment that he says will take only about two years to pay back. He expects to save about $125,000 a year on electricity, parts and labor.

“I wanted to be a front-runner,” is how he explains the switch.

For now, Mr. Gauthier is a lonely front-runner in sports lighting, though LEDs are gaining wider adoption in airports, stores and many other places. While other sports locations use LEDs to light scoreboards, concession stands and the like, the Bell Centre is the only major league sports site in North America to use only LEDs to light its playing surface.

Other operators have resisted making the switch, even though so-called performance lights are the No. 1 or No. 2 consumers of electricity in arenas and stadiums. A big reason, here and with other large-scale energy-saving projects, is the payback period, the time it takes for such an investment to pay for itself through savings. While prices vary widely, LEDs cost about $1,500 each, roughly four times as much as incandescent lamps. For operators with money invested in stocks of older lights or building upgrades incorporating them, the payback period can be more than three years, industry experts said.

“Definitely, there are some long-term savings,” said Sean Langer, director of operations at the KFC Yum Center in Louisville, Ky., home of University of Louisville basketball. “But we have to ask, what is the return on investment? Seven to 10 years is a hard pill for my boss to swallow.”

Other factors limiting adoption are more specific to sports. LEDs do an excellent job of lighting specific locations, but illuminating wider spaces — like baseball, football and soccer fields — is more problematic. And some broadcasters are reluctant to use LEDs in TV studios at stadiums because they are more complicated to install.

“With conventional technology, you plug the light into an outlet controlled by a lighting console,” said Mick Smith, senior designer at Ferri Lighting Design & Associates, which has installed LED lights in television studios. “LEDs are intelligent fixtures. They each need a power and data cable that are often connected to other fixtures. It’s like setting up a chain of 500 computers, and it’s a lot harder than just plugging in your home computer.”

Sports leagues are studying LEDs and gathering the opinions of players, referees and broadcasters. But teams have varying priorities because their buildings vary by age and architecture. Nine National Hockey League teams share arenas with National Basketball Association teams, and each league has its own lighting rules. Leagues must vet manufacturers for cost and reliability.

“It’s something that is going to happen, it’s just a question of when we are going to release our standards,” said Omar Mitchell, the head of sustainability at the N.H.L. “If it’s good, we should be doing it.”

He and other sports and lighting experts said that as their price fell, LEDs would be adopted more widely as performance lights. They switch on and off instantly. Their brightness and lack of flicker show well on high-definition television, especially slow-motion replays. For further energy efficiency, they are dimmable, which lets arena operators use, say, 80 percent of their capacity during games (100 percent is often unnecessary) and 30 percent when crews clean the arena. Because LEDs are programmable, operators can easily create light shows and in-game promotions.

“It’s not only to replace existing lamps, but bringing operators into a new world to create effects and game presentation,” said Jean-Louis Legault, the president of LED Innovation Design, the Canadian lighting company behind the Bell Centre’s new system. “Every single lamp is an addressable pixel.”

Perhaps the most novel use of LEDs will be in clubhouses, where they have the potential to alter the game subtly by changing players’ moods. LEDs can be fine-tuned to simulate daylight and to try to recalibrate players’ circadian clocks.

The Seattle Mariners, for instance, worked with John Hwang, the chief executive of PlanLED, to replace fluorescent lights with LEDs this summer in the team’s locker room, training room, dining room and weight room. The team hopes that by brightening and dimming the lights, players can overcome jet lag faster and become energized before games and cool down afterward.

“Living in Seattle, people talk about the seasonal disorder and cloudy days, but I didn’t think there was a way to overcome it,” said Scott Jenkins, head of ballpark operations for the Mariners. “We can make the clubhouse a place where the players want to spend time and it supports their performance.”

While the impact of LEDs on human physiology is still emerging, “there is a lot of basic scientific support for why they should,” said Steven W. Lockley, a professor in the Division of Sleep Medicine at Harvard Medical School.

Mr. Jenkins and Mr. Hwang said they would need a full season to assess the lights more precisely. But early reactions from players and coaches suggest the lights have great potential.

“We can mimic what we would consider the ideal light environment for humans,” Mr. Hwang said. “It’s the introductory level, but we feel it’s historic.”

By New York Times