Originally published by tED Magazine. Reprinted with permission.

Outdoor stationary lighting covers area and roadway, parking, and building exterior lighting. This lighting provides proper illumination, cultivates a sense of security, and draws attention to businesses, buildings, and public spaces. Due to its high utility and the amount of energy it requires, outdoor remains one of the most important lighting markets.

Traditionally, HID lamps dominated the sector in no small part due to their high light output enabling high mounting and wide spacing. These lighting systems presented an early target for LED, which offered immediate advantages of high optical efficiency, energy savings, and long service life.

In 2019, the Department of Energy forecasted that LED would displace traditional sources in nearly all outdoor applications by 2030. For the past decade, manufacturers have overwhelmingly focused their R&D efforts on LED, while HID quickly shifted into market decline. The result shows in today’s offering, which offers a wide range of utility covering optics, color output, controllability, connectivity, and energy efficiency. This continues to make LED compelling for replacing remaining traditional technology but now also well positions it to upgrade early-generation LED installations.

Today’s LED solutions are highly efficient. Outdoor lighting was an early adopter of LED sources that had efficacies of about 60 to 70 lumens/W. Today’s LED luminaires can achieve up to 130 lumen/W, with advanced options recently reaching a milestone of 200 lumens/W. This makes older LED installations suitable for proposal to upgrade to the latest LED solutions, which can offer energy savings but also other forms of value.

Today’s LED luminaires can make effective replacements of LED-HID replacement lamps. Early LED replacement lamps offered quick energy savings but inherited the same weaknesses as HID lamps, making them attractive for upgrading to new luminaires, said Eric Gibson, Director, Product Market-Commercial Outdoor, Acuity Brands (AcuityBrands.com).

“When LED replacement lamps are used in existing HID housings, they automatically incur a loss of around 30 percent of the light output,” Gibson said. “In addition, LED replacement lamps are thermally sensitive and will age quickly in these enclosed housings. New luminaires designed around LED sources are vastly more efficient and can have tremendous improvements in light distribution, giving more light and better uniformity than replacement lamps.”

Image courtesy of Acuity Brands.

Tunable LED luminaires can effectively beautify buildings, areas, and landmarks. Effective outdoor lighting design can articulate architecture, highlight landmarks, and otherwise beautify spaces such as nighttime shopping areas. Today’s LED luminaires offer more precise optics to accomplish this both artistically and responsibly, while tunable LED luminaires—intensity and color—allow a wide range of artistic effects, from setting different colors to producing dynamic light shows.

“There is a growing desire for cities to illuminate their iconic buildings, bridges, and monuments,” said Keith Eagle, Vice President & General Manager, US Professional Channel, Signify (Signify.com). “This helps create an appealing identity, civic pride, and tourism.”

Today’s LED luminaires allow businesses to be good neighbors. Numerous municipalities have enacted ordinances that address light trespass and/or skyglow. Responsible outdoor lighting also shouldn’t produce glare that can be irritating to or outright disable vision. LED luminaires with well-designed optics can produce precise light patterns, increasing both quality and efficiency while enabling the lighting owner to be a good neighbor.

“The key to outdoor lighting is to put enough light where and when it’s needed, and to minimize any light where and when it isn’t needed,” said Gibson. “This typically manifests in products with superior light distribution to cover large areas while cutting off high-angle or nuisance light that can produce glare.”

Responsible outdoor lighting minimizes glare for safety. Image courtesy of Signify.

Serviceable luminaires add value by extending service life. Many higher-quality outdoor LED luminaires are serviceable in that the driver is easily accessible and is replaceable. As the driver may fail before the light source consumes its useful life, this can extend the life of the luminaire.

“Replacing a driver is very similar to replacing an HID ballast,” Gibson said. “However, it is critical that the driver matches up to the specific LEDs in the luminaire. It is not advisable to replace a failed driver with an off-the-shelf driver and expect positive results. Replacement drivers should come from the factory directly. For this reason, many low-cost outdoor lighting products are not serviceable and must be replaced when failures occur.”

Responsible outdoor lighting features optics placing light only where it’s needed, reducing backlight when needed to avoid light trespass. Image courtesy of Acuity Brands.

Today’s LED luminaires are readily controllable. In keeping with the maxim that responsible outdoor lighting produces only the right amount of light when and where it’s needed, lighting controls can play a key part. Outdoor LED luminaires are available that feature onboard occupancy sensing for automatic dimming or shutoff, photocell, color control, and/or wireless connectivity for implementing scheduled/programmable operation and sending data. These measures can add value by minimizing energy consumption and lighting use while also potentially generating data that can be used for a variety of measuring and monitoring applications.

The features may be installed with the luminaire, or the luminaire may be upgradeable for future incorporation of automatic controls and connectivity. Taking the concept to the leading edge, outdoor luminaires can serve as platforms for a variety of inputs and outputs, from measuring air quality to solar panels to providing broadband access to local users to notifying the system operator if there’s a luminaire needing maintenance.

“Cities and municipalities are looking for ways to modernize their infrastructure, save energy, reduce carbon emissions, and enhance the quality of light and life for citizens,” Eagle said. “For example, customers can collect traffic/parking, environmental, noise, and other data and visualize these insights in a single Cloud-based management system—driving the path to a smarter city. Meanwhile, broadband luminaires can help unlock wireless connectivity from the lighting grid. Cities can tap their streetlighting to create a scalable platform that opens opportunities for Wi-Fi access/digital equity and public safety.”

LED outdoor lighting offers sales opportunities for electrical distributors. In the early days of the LED revolution, energy savings—basic lighting performance for less energy—was top dog. These days, it is about the combination of energy savings, performance, and overall value.

“Electrical distributors should seek to understand what the customer is trying to accomplish beyond basic illumination and energy savings,” said Eagle. “Listen to their requirements and long-term goals. You stand to become a trusted partner in this segment.”

SIDEBAR:
DLC LUNA Product List

The DesignLights Consortium (DLC) lists a large number of LED outdoor lighting products at the SSL Qualified Products List at DesignLights.org. Many utility rebate programs qualify products by requiring this listing.

In December 2021, the DLC launched LUNA Version 1.0, a subset of the SSL Qualified Products List. This listing identifies outdoor LED luminaires that save energy but also promote responsible outdoor lighting. As of July 2023, 65 products gained listing, with more in review.

The DLC subsequently released a sample lighting ordinance for adoption by municipalities. It offers a choice of either requiring DLC-listed luminaires or stating a list of performance requirements from which municipalities can review products themselves.

Craig DiLouie

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