Light Reading

Last year, two roads diverged in the sports field lighting industry. One company took the road less traveled - a path it claims leads to energy efficiency - and since then, that has made all the difference.

When Musco Lighting of Oskaloosa, Iowa, introduced its Light-Structure Green system last spring to replace the company's previous standard lighting system, it broke ranks with its industry peers in more ways than one.

Thanks to photometric technology enhancements (or simply put, improvements to the fixture's lamp and reflector) and the fixture's ability to provide what Musco calls "constant light levels," Light-Structure Green is said to offer substantially more efficient light control and is thus labeled environmentally friendly. Given the fact that outdoor sports lighting systems are built using power-guzzling 1,500-watt metal halide lamps - an array of 30 to 50 fixtures at a high school football field is not uncommon - Musco's new product has understandably generated significant buzz.

"It reduces spill and glare, so it diminishes energy consumption by 40 percent," says Beth Danowsky, a Musco grant specialist who connects clients with local energy-efficiency incentive programs. "We're seeing a demand for this kind of product, simply because a lot of our customers are school districts, cities and nonprofit organizations that are feeling a greater squeeze on their budgets. They're finding - especially if they're lighting multiple fields or if they have a field with old lighting - that they're using a lot of energy. We can help them out by diminishing their energy costs."

Such claims have spurred intense debate among sports field lighting manufacturers regarding not only the real possibility of achieving energy efficiency, but also whether any attempt to do so necessitates forgoing established industry best practices.

Those accepted standards are written by the Sports & Recreation Areas Design & Application Committee of the Illuminating Engineering Society of North America, a New York-based nonaffiliated, nonprofit organization that sets lighting standards for a variety of applications - from office buildings to highways. Functioning in a capacity similar to that of ASTM International's F-08 Committee on Sports Equipment and Facilities, IES's sports committee publishes a set of recommended practices for the lighting of outdoor sports and recreation areas (RP-6), having updated them most recently in 2001.

According to Jon Brooks, a lighting designer and electrical engineer with Architectural Engineering Design Group Inc. of Denver, the IES way is the only way. Says Brooks, "If you want to know how to light functional sports facilities, IES is the standard."

It should be noted that there are many facets of IES's 106-page RP-6 guidebook, and that no manufacturer is beholden to any one section over the other. "The IES standard is a huge statement; there are a lot of things that one could follow," says Brooks. "IES makes recommendations for minimum foot-candles, for spill light, for direct light versus indirect light. It definitely gets down to the nitty-gritty."

Indeed, it is the minutiae that are currently being debated by sports field lighting manufacturers. What should be of greatest concern to end users is how sports field lighting systems respond to IES's recommendation regarding what it calls "maintained average illuminance."

This concept focuses on a lighting system's ability to provide a consistent level of lighting over time. For example, the RP-6 standard recommends that a football field lighting system maintain at least 50 foot-candles of light for collegiate play, and a minimum of either 20 or 30 foot-candles on high school fields, depending on the size of the venue.

To compensate for the deterioration of light quality - whether due to dirt buildup on fixtures' optical lenses or natural lamp depreciation - manufacturers account for what they call a light loss factor (LLF) in their lighting systems' designs. In other words, straight out of the box, a lighting system will provide more light than it will after, say, 10 years of operation. For years, a 20 percent LLF has been widely accepted as the unofficial industry standard - although be aware that this specific number does not appear anywhere in the IES RP-6 guidelines.

"For suppliers to maintain 50 foot-candles, their original design has to factor in maintenance," says Dan Dwyer, vice president of sales and administration with Hillsdale, Mich.-based Qualite Sports Lighting Inc. "We take 50 foot-candles and divide it by 0.8 to get 62.5. We have to light the field to 62.5 foot-candles when the switch is first turned on. That's what we do. That's what Hubbell does. That's what Universal Sports Lighting does. All the main guys do it - except Musco."

What Musco does with Light-Structure Green is offer Constant 25T, a 25-year warranty and maintenance program. Musco guarantees, among other things, that its systems will maintain constant light levels. "The IES sports committee recommends minimum average light levels," says Dave Barker, Musco's developmental application engineering manager and a member of the IES sports committee. "And with that, there's a plus/minus 10 percent factor to account for light meters and other variables in the process of taking readings out in the field. That's in RP-6." (The IES 10 percent allowance would imply the acceptability of 45 foot-candles from a lighting system originally specified to provide a minimum of 50 foot-candles.)

That constant level of lighting is enabled, in part, through the replacement of lamps when they reach the end of their expected life. (According to Barker, Musco has lab-tested its newly designed lamps to reach a life span of 5,000 hours, instead of their previous 3,000 hours.) But it's also due to the use of a multiple-capacitor technology that adjusts power flow as needed to each fixture over time. "We under-drive the lamp at first and then as it deteriorates, we boost the energy to the lamp," says Barker. "We try to maintain a constant illumination throughout the whole life of the lamp, and with that there are some energy-saving benefits. We actually reap a longer lamp life and lower maintenance costs. It works."

But while Musco proudly markets the Light-Structure Green system as being energy- and cost-efficient, other sports field lighting manufacturers would like proof that it actually works as intended. "I tip my hat to them that they're trying to do something that saves energy. It's a noble effort," says Dwyer. "But it's a maverick product. It's untested."

Russ Owens, a member of both IES's board of directors and its sports committee, also expresses some skepticism - if only for the fact that so far he's been able to learn very little about Light-Structure Green. "Because the system is new, the manufacturer has been very reluctant to give out any of its data to any consultant I know," says Owens, who himself is president of West Coast Design Group, a lighting design and electrical engineering firm in San Juan Capistrano, Calif. "I usually don't take any manufacturer's word for anything. I'm a wait-and-see kind of person. I know manufacturers are always optimistic about their stuff and have this `We slice bread better than the previous guy' kind of a thing. And while I think that's always possible, anytime there's an advance in technology, you have to observe it in real life in one or two life cycles. The technology can prove itself in a lab, but you have to put it out in the real world and observe it."

In particular, Owens would like to know more about the inner workings of the Light-Structure Green's multiple-capacitor technology. Owens believes that these capacitors, in essence, combine to function as a dimmer switch - however, high-intensity discharge (HID) systems can't dim like household incandescent lights; power output must be increased in specific steps. In theory, such technology can increase the amount of electric current flowing through a ballast in order to maximize light output at various stages in a lamp's life span, allowing the system over time to consume only as much power as needed. But the concept isn't as straightforward as it may sound.

"Metal halide does not dim in a straight line. It depreciates much quicker at the onset and then flattens out," says Owens. "So it's not a linear curve." In other words, if a multiple-capacitor system is dependent on an analog timing mechanism to increase current flow at, say, every 500 hours, the light output might be 100 percent at installation, 80 percent at 500 hours of usage, but decline less significantly as it approaches 1,000 hours, to perhaps only 70 percent.

Essentially, then, an end user has the option of choosing either a system that carries the promise of providing a minimum of 45 foot-candles throughout its lifetime or one that will offer at least 62.5 foot-candles at installation - an initial difference of 28 percent in illumination that translates to slightly more than a 30 percent savings in energy consumption.

That said, end users are faced with a simple trade-off - do they prefer less light or a larger energy bill? "It's like driving your car down the road," says Chuck Lindstrom, president of Universal Sports Lighting in Atlanta, Ill. "You can get better gas mileage if you drive at 40 mph than you can at 70 mph. But it takes you almost twice as long to get there. Now if you want to get there at the same time, guess what? You're going to guzzle up a little bit more gas."

While holding firm to his impartial stance, Owens suspects that end users will be able to get by with less light - especially considering that a number of them already do. "Little League demands 50/30 [50 foot-candles for infield lighting and 30 foot-candles in the outfield]," he says. "I've measured many a field out here in Southern California, and not one of them has ever met that light level. And yet, they continue to play.

"We redid a high school football field that four schools were using. Between the four schools, they probably turned out 30 Division I football players who went on to USC, Stanford, Oklahoma - big-time programs. They had an old lighting system and were getting 5 foot-candles along the sidelines and 3 foot-candles in the middle of the field. So could they play at those levels? Absolutely."

But what about collisions and other player safety issues? Owens is quick to remind field owners that the recommended light levels published by IES are just that - recommendations. "There are no empirical data that any of our values have any meaning relative to anything," he says. "Unlike, say, roadway standards - for which there might be years of data and research on accident compilations under certain kinds of light levels - nobody, to the best of my knowledge, has compiled that sort of data for sports fields."

It also remains to be seen how Musco's claims of Light-Structure Green's energy efficiency compare with real-world costs. According to Barker, in just a year's time the company already boasts 1,000 Light-Structure Green installations - a fact that, in his mind, offers proof that there's a great deal of truth behind Musco's sales pitch. "Musco is a profitable company," he says. "But we're not going to stick our neck out with a guarantee of 25 years of meeting light levels without sufficient confidence in our product to meet that guarantee."

Musco isn't alone in the quest to improve the energy efficiency of sports field lighting systems. Of the five companies that Owens says have the ability to consistently compete for market share - GE, Hubbell, Musco, Qualite and USL - all have made improvements in recent years to the design of their fixtures' reflectors and visors, changes that have helped reduce light spill and thus use light more efficiently.

Qualite is even in the initial stages of partnering with a company to provide solar-powered lighting for stadium and sports complex ingress and egress areas. This initiative was spurred by the fact that recent light-spill reduction efforts have significantly cut back the excess light from sports field fixtures that formerly illuminated parking lots and pathways. And while the industry's focus, at least for the time being, will likely dwell on energy efficiency, Qualite's Dwyer recognizes the road ahead may have a few more turns. "Keeping energy costs to a minimum will continue to weigh heavily in the decision-making process of future customers," he says. "Everyone in the sports lighting industry will be challenged to improve and develop products to meet customers' needs."

For individuals like Owens - who has a special vantage point, both as a standards authority and as an independent lighting consultant who has worked with all five of the industry's major manufacturers - that challenge involves playing a firsthand role in fostering the ongoing debate of technological ideas. But it doesn't mean he has to keep the peace.

"The manufacturers always battle with each other, and of course, Musco, because all they do is sports lighting, is out front. And any time you're the lead dog, you're probably much more prone to having little darts thrown at you," says Owens, who resists recommending one company over another to his municipal clients. "Take the city of Irvine. Musco is the city's standard. I don't even ask the question because I know what the answer is. You know, it doesn't bother me. It's good for Musco. It's not my job to try to fit GE or Hubbell or Qualite or USL into a project and do their fighting for them against Musco. They all make good equipment."