When the Mercedes-Benz Superdome, in New Orleans, went partially dark with 13 minutes and 22 seconds to go in the third quarter of the 2013 Super Bowl, fixing the defective relay in the metal halide high intensity discharge (HID) system used in the stadium’s main overhead lighting accounted for only a portion of the half-hour delay. Power was restored after a few minutes, but the fixtures took much longer to reach full brightness—and only then could play resume.
The U.S. Energy Information Administration reports that metal halide HID luminaires can take up to 20 minutes to reach 90 percent brightness, compared to LEDs’ near-instant on/off functionality. Although HID fixtures are the most common overhead luminaires used in open stadium and indoor arena lighting applications today, their prevalence is being challenged by the rise of solid-state technology as professional, university, and even community stadiums and arenas increasingly play host to more than just sporting events, expanding their repertoire to include concerts, conferences, and even retail and dining. The result is changing the very nature of live sports for stadium owners, the fans, and, of course, the players.
How might the situation in New Orleans have played out with today’s LEDs? “Would it have still happened? Probably,” says Jay Wratten, a senior associate for lighting design at WSP | Parsons Brinckerhoff in Boulder, Colo. “But it would have been a commercial break, not a 30-minute delay.”
Impact: The Owners
Professional arenas began making the switch to LED long before stadiums because they are illuminated year-round for games and events to expedite the investment’s payback period; a large, open stadium with metal halide, on the other hand, may only use light for a few hundred hours each year because the system is so costly to run. As LED costs trend ever lower and their performance improves, facility managers are looking to the technology for features like color tunablity and fixture control that offer customization, allowing the space to be used for more and different events.
When Eaton’s Ephesus Lighting business, in Syracuse, N.Y., retrofitted the Bridgestone Arena, in Nashville, Tenn., in 2015, the luminaire manufacturer replaced the existing HID system with LEDs, allowing facility managers to create unique lighting scenes for the NHL and NCAA basketball games that it hosts. “They can hit a button and go into hockey mode and have a cool temperature light, and [then] they can hit a button and go into basketball mode and have a warm temperature light and maintain the same level of intensity that they need for illuminance and for uniformity,” says Eaton’s Ephesus Lighting business president Mike Lorenz.
Additionally, owners can adjust the fixtures’ CRI to enhance team colors on the field, ice, or court, for example, or create a theatrical lighting experience that makes the event memorable for fans; in the locker room, bright light can be used to help players prepare for a game while warm light can be used post-game to help them decompress. “It’s all customizable based on what event you are holding and what you want the end user to ultimately experience,” says Dan Webb, the lead electrical engineer for Henderson Engineers’ work on the forthcoming Los Angeles NFL Entertainment District Stadium.
Broadcast quality is another consideration for professional and some collegiate stadiums. Using LED sources reduces flicker for high-definition broadcasts, increasing the frames per second allowed without making flicker perceivable to the human eye, Webb says. And “if we can get the quality of the lighting to look more like [what] the camera wants to see, then [the broadcast networks] have to make fewer adjustments and that improves the quality of the video,” Wratten says. LED systems’ adjustability affords another advantage—adjusting light levels when meeting broadcast requirements is not necessary.
Another benefit is that instead of reacting to a failed fixture, LED lighting systems like the one Eaton’s Ephesus Lighting business makes offer diagnostics to monitor the health of the system—such as humidity, temperature, energy consumption, and hours of operation, to indicate when it may need to be replaced.
Impact: The Fans
With stadium owners seeking to get maximum value for their investment in LED lighting, fans can expect an immersive experience. “The well-lit stadium is a stage,” says Wratten, whose firm is working with HOK on the lighting design for the Mercedes-Benz Stadium in Atlanta. “We can essentially spotlight the center of the 50-yard line with four, eight, 12 fixtures, and leave the rest of the stadium dark or make it a color.”
That technology is also being used to create dynamic, theatrical experiences previously impossible with metal halide, and as a result often relegated to video screens. These include effects like strobing, chasing, and pulsing to highlight good plays and scores; announcing the starting lineups; integrating music or video; and syncing up with sensors for occupancy or temperature. “You’ve now taken a system that was historically one-dimensional and turned it into a multidimensional tool that can be used to enhance the fan experience, which is important to sports venues that are trying to attract people,” Lorenz says.
That experience will soon extend beyond the field. Swapping diffuse metal halide luminaires for point-source LED fixtures has required lighting designers to think more about how the seating area, or “bowl,” is illuminated. “We used to not light the bowls directly,” Wratten says, citing light spill from the field. “But because LED fixtures are so much more focused, we’re actually adding a totally secondary system of bowl lights, and we can control those systems independently.” That could mean turning down those lights during game play, for example, enough to draw attention to the field while still allowing fans to capture the experience on social media. “How do you design the lighting so that the selfies—the ‘Check out the view from my seat’ videos—look good?” Wratten says. “For a stadium that has a solid façade, we may increase the light level in the bowl so that your selfie shot actually looks a bit better than it could if we just had the field glowing brightly behind you.”
Impact: The Players
LED lighting deserves particular consideration for the way it stands to impact the players, such as adding the ability to adjust the CRI to meet the specific needs of the sport being played, especially in venues that host a variety of events. For sports that feature fast ball movement, such as tennis or baseball, a higher CRI provides sharper light and reduces shadowing.
Ethylene tetrafluoroethylene (ETFE) roofs, such as those topping the U.S. Bank Stadium in Minnesota and the forthcoming Los Angeles NFL Entertainment District Stadium, also help by bringing daylight onto the field year-round. “Fabric roofs allow the light to come in but you don’t see the ... sunlight that you do with an ETFE roof,” says John Hutchings, principal at HKS, in Dallas, which designed both stadiums. “It’s a different kind of feel.”
However, more daylight may not reduce demand for electric lighting. “If you look at an open-air stadium that’s got a 2 p.m. game, the lights are on, [the broadcast networks] are going to want those lights on so their cameras are ready if the sun goes behind a cloud or there’s any change,” Wratten says.
And even in the same sport, different teams have different preferences. “When you look at a market like Los Angeles, where two NBA teams play in the same venue (the Staples Center), you’ll notice that the Lakers prefer their lighting to be more theatrical and brighter, focused on the court, while the Clippers like a broader wash of light that includes the first few rows of fans,” Webb says. “Some of that color temperature and lighting adjustment is just a personal preference, while some of it is critical to enhance the sport that is being played.”
One challenge for LED-lit stadiums is glare. The optical control afforded by LEDs results in visual hot spots—if a player isn’t standing in the direct line of a fixture’s aiming, it may appear off, making the fixtures that do shine right at them brighter by comparison. Another consideration is rendering the ball, a need that differs by sport. In baseball, for example, a pop-fly after dark can go above the light level and become difficult to see. “[We’re] starting to think about the field of play not as a horizontal surface but as a volume of space where the ball needs to travel through and be rendered all the way,” Wratten says.
An all-inclusive LED approach is only beginning to take hold in stadiums, and only the most high-profile are likely to see overhauls for the time being, with smaller university, college, and community facilities’ lighting choices still being driven primarily by cost. Still, the potential of LEDs for sports lighting is becoming clearer.
What can LEDs provide stadiums in the future? A platform for integrating a variety of systems, from location positioning technology that would allow a fan to have a drink delivered to their seat, to occupancy sensors that would notify facility management when a bathroom may have been trafficked enough to require cleaning, to security and emergency response systems. “To get that level of integration,” Wratten says, “you’re going to need a stadium that’s been designed post Internet of Things, where, holistically, those [systems] tie together.” •
This article was originally featured on our sister site ARCHITECTURAL LIGHTING >>