Digital SSL's mega disruptor will be Power over Ethernet (MAGAZINE)

Power over Ethernet distributes DC power over inexpensive data cables instead of costly conventional lines, threatening utilities, electricians, and contracting firms, explains Mark Halper. Meanwhile, the technology turns LED luminaires into data nodes, allowing IT companies to muscle into the lighting sector.

Digital SSL’s mega disruptor will be Power over Ethernet
Digital SSL’s mega disruptor will be Power over Ethernet

Power over Ethernet distributes DC power over inexpensive data cables instead of costly conventional lines, threatening utilities, electricians, and contracting firms, explains MARK HALPER. Meanwhile, the technology turns LED luminaires into data nodes, allowing IT companies to muscle into the lighting sector.


Are you ready for a rumble? The advent of Power over Ethernet (PoE) technology is setting up a heavyweight title fight between Big Lighting and Big Networking for control of future indoor commercial lighting products and infrastructure. Indeed, PoE can replace the AC electrical grid in buildings, deliver energy efficiency beyond what inherently efficient LEDs already offer, and enable networking for further savings and adaptive controls. It’s really no surprise that the evolution of smart solid-state lighting (SSL) has garnered the attention of companies such as networking and Ethernet stalwart Cisco. But even companies known traditionally for their lighting have begun to realize the potential of PoE — for example, Philips, with its involvement in a large PoE-based commercial project in Amsterdam (Fig. 1).

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Consider that when teachers go for their information technology training at Miami-Dade County Public Schools, a big lesson immediately stares them in the face even if they don’t realize it: The ceiling lights that illuminate the classroom draw electricity from modern Ethernet data switches and cables instead of from a conventional 120V electrical grid.

Digital SSL’s mega disruptor will be Power over EthernetDigital SSL’s mega disruptor will be Power over Ethernet
FIG. 1. A new Amsterdam building called The Edge features the largest Power over Ethernet (PoE) installation that is used to power and connect SSL fixtures, enabling workers individual control of light in their space.

What’s more, the same Ethernet doubles as an information conduit carrying instructions straight to the lights, turning them on and off, and making them shine at desired brightness levels, correlated color temperature (CCT), and color. It’s all linked into the same network that does all the other things a school IT system does — carrying emails, announcements, presentations, administrative instructions, coursework, and the like (Fig. 2).

The moral of the story: Miami-Dade is on the cusp of PoE LED lighting, a technology in its infancy, and one that many people believe will become the standard method of lighting buildings as it replaces expensive, electrician-reliant, century-old ways. “It’s the future,” said Debbie Karcher, Miami-Dade’s chief information officer. “I don’t know why it wouldn’t be.”

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FIG. 2. Miami-Dade Public Schools simply switched off their old lights — the dark troffers in these photos — and installed new Power over Ethernet fixtures without having to wire them to electrical cable. The lights can also be controlled via the PoE system for brightness and color temperature changes.


PoE takes advantage of two LED lighting attributes: low power requirements and affinity for digital connectivity and control. The world’s 120V and 240V AC electrical wires and all the cost, regulations, and infrastructure that go with them greatly exceed what LED lights need. LED luminaires contain electronics that knock those levels down, typically to 12V DC. Ethernet cable, which is already present in offices, safely carries lower DC voltages — which in turn do not require electricians and all their trappings.

And because LED lighting is based on diodes combined with other semiconductors in a driver circuit, they are ready-made to become members of the Internet of Things (IoT), serving as data network nodes to receive and collect information using sensors embedded in LED housings and luminaires (Fig. 3). “The possibilities are endless,” Karcher observed.

It has happened before

The idea of using Ethernet as an electrical pathway is not new. A lot of data-connected office equipment such as phones and printers already use it, tapping into the same twin benefits of power and data that are set to take hold in lighting. For more than a decade, PoE has worked hand-in-glove with voice over IP (VoIP) to transform the office telecommunications model from the historically used clunky phone exchanges supported by costly contracts with big incumbent telco providers, to one that routes calls inexpensively over VoIP data networks, handling voice as packets of data. The same sort of technology upheaval and convergence could soon start to shake things up in the lighting industry. (After this article went to press, LEDs Magazine learned of upcoming announcements that could culminate in a much-anticipated partnership between Philips and Cisco for PoE and connected lighting.)

But while PoE may well be, as Karcher noted, lighting’s future, it is not yet its present. PoE lighting installations today are characterized either by a few vendor-driven showcase installations such as at the 14-floor office building in Amsterdam led by Dutch lighting giant Philips, and at the C-suite in the San Jose, CA headquarters of Cisco; or by small pioneer projects such as Miami-Dade, the country’s fourth largest school district, which has been using the technology since April in four classrooms and two lecture rooms dedicated to training teachers and staff in the use of IT systems. Miami-Dade uses luminaires from a PoE specialist called NuLEDs, a small husband-and-wife startup company located in Carlsbad, CA.

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FIG. 3. Power over Ethernet offers an integrated power and connectivity grid for LED-based lighting, enabling programmatic and adaptive control of lighting as well as control by individual employees of their personal work space.


For the concept to truly take off, more products and services must hit the market. They include luminaires such as those already available from NuLEDs and from other PoE enthusiasts like Innovative Lighting of Roland, IA. The PoE-tailored lights use diode strips rather than conventional tube or bulb form factors, and house them in standard-size ceiling fixtures. They also eliminate the electronics typically used today by LED lighting to reduce voltage and to convert main-line AC to DC.

Emerging products also include the Ethernet switches such as those that Cisco is refining with greater PoE capabilities and power capacity (Fig. 4). For Cisco, PoE lighting is vital to its overarching “Internet of Everything” strategy. Also part of the mix is software that helps tie it all together, provided by companies such as UK-based Philips spinoff amBX.

Whose industry is it?

And while that all plays out, a good old “co-opetition” scenario is unfolding as conventional lighting companies like Philips go after a market that also keenly interests info tech giants such as Cisco and Google. The two sides will have to figure out how and when to collaborate or compete. It’s reminiscent of the ongoing incursions that Internet companies have made on traditional big media, as companies like Google, Comcast, Netflix, YouTube et al. work sometimes with and sometimes against each other in a rock ‘em–sock ‘em environment that can feel like the on-again, off-again wars and alliances in old Anglo-French relations.

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FIG. 4. Components in PoE systems, such as this Ethernet switch, are continually being refined with greater capabilities and power capacity as more is demanded of networked lighting and the Internet of Things (IoT) expands.


So far, Big Networking and Big Lighting seem to have a checkered relationship. Cisco is nowhere to be seen in Philips’ project at The Edge (as shown in Fig. 1), the largest publicly known PoE installation, where Philips provided not only the lighting but also supplied the Ethernet switches through either a third party or, according to one source, by custom building them. Likewise, Philips is not supplying the luminaires at the Cisco C-suite in San Jose. Those come from NuLEDs.

But all is not lost between the two big companies. For instance, Philips has installed a PoE system across five floors at Cisco’s Canadian corporate headquarters at an office tower in Toronto, Canada. Both Philips and Cisco told LEDs Magazine that they expect to announce major partnerships in the near future related to connected lighting and PoE. Whether that means they will be partnering with each other remains to be seen.

Both industry representatives have the same goal: to make full use of the digital aspect of LED lighting, such that they control lights in imaginative ways and use them as valuable information points for collecting and disseminating information. Both The Edge in Amsterdam — where anchor tenant Deloitte is a principle user — and Cisco’s five floors in Toronto allow office workers to manage overhead lights using computer controls and in some instances via smartphones; similar controls of task lamps should soon be available. The Edge also deploys a newfangled lighting-based location technology called visible light communication (VLC). For more info on VLC, see our article on a Philips Lighting pilot project in France.

The contenders

It’s not yet clear who will own this brave new lighting world. “One of the big questions is: Does lighting co-op networking, or does network co-op lighting?” noted Wendell Strong, PoE lighting manager at Iowa’s Innovative Lighting. “There’s going to be a battle.” However it comes out, he added, “The traditional lighting industry is going to have to radically change.” Innovative has been making LED lighting products since the 1990s and now has a strong PoE focus. Like NuLEDs, it has a few small pilot installations with a product line it calls Genisys, such as at a couple of Waterloo, IA outlets of the high-tech laundromat chain Clean Laundry (Fig. 5).

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FIG. 5. LED lighting such as Innovative Lighting’s Genisys can enable additional benefits in drawing from Power-over-Ethernet networking, including higher-level programmability for longer lifetime in commercial scenarios, such as the high-tech laundromat chain Clean Laundry.


“There will be newcomers who are not current players in the lighting market, and that could be very disruptive,” said John Niebel, CEO of amBX, the Philips software spinout. As amBX knows, partnerships between lighting and networking companies will be key. amBX has just lit up a small pilot PoE deployment at the University of Strathclyde in Glasgow, working with Cisco on the IT side and with NuLEDs as the luminaire provider.

NuLEDs’ chief business development officer Lisa Isaacson added that the as-yet unresolved “go to market” question is one that is holding PoE somewhat at bay. “The lighting industry has been pretty established in the way lighting gets sold in the buildings,” Isaacson noted. “So it’s kind of changing who does the sale, who does the installation, who does the follow up. If the light fixture goes out, who gets called? Is it an IT issue? Is it an electrical issue? It’s a new set of skills that need to be used when you’re doing the troubleshooting. It’s going to be pinging the light fixture. It’s working on the IT network side of the issue. So it’s very disruptive.”

Going to school

The Miami-Dade installation illustrates how PoE combines the worlds of lighting and computer networking. The school is using NuLEDs luminaires and controls, along with Cisco switches to adjust biodynamic lighting in the classrooms, experimenting with the scientific findings in the area of human-centric lighting (HCL), which show that different energy spectra in light can stimulate behaviors such as learning, attentiveness, and relaxation. In general, white and blue-tinged light with cooler color temperatures is meant to trigger alertness, while light in the warmer color temperatures — the reds and oranges — promotes relaxation.

“I would really like to trial it after lunch, when people are tired,” noted Karcher, who added that it’s too early to tell yet whether the color fluctuations are having an effect room. Still, she’s interested in expanding the technology into other classrooms. For instance, some of the older areas of the school do not have windows, an antiquated design feature tied into the school’s designation as a hurricane shelter. “It would really make sense there,” she said.

Another possible application would be to tune the light spectrum to ideal growing conditions for plants like orchids in Miami-Dade’s biotech facilities. In another, Karcher envisions tying cameras or other sensors to the lights that would route physical security information through the data network. “The potential is unlimited,” said Karcher. “Anything you can attach to a computer you can attach to a light.”

Remember the energy benefit

The school is a living exposition of before and after — its old lighting fixtures remain in the ceiling, dark, while light shines from the NuLEDs luminaires, which required no electrical work other than running Ethernet cable to them. Miami-Dade schools also had a good PoE precedent. They already use PoE to power other operations, such as Wi-Fi, noted Javier Perez, executive director of infrastructure and systems. By tying LED lighting into the PoE, the school is also aiming at significantly reducing its electricity bill, he said.

Another NuLEDs PoE lighting user, Independence Blue Cross, is also eyeing big energy reductions from the LED ceiling lights at its disaster-recovery data center in Reading, 70 miles west of its Philadelphia, PA headquarters, where it has replaced about 60 fluorescent fixtures with 15 2×2-ft LED fixtures. The retrofit covers about 40% of the 6000-ft2 facility. “We quartered the physical footprint,” reported Independence data-center architect John Martin. “And it’s all using about 10% percent of the energy.” Martin said the power requirement of his NuLEDs luminaires is roughly 400W, compared to 4000W for the old fluorescents.

While energy reduction is something that is more germane to the LED sources than to the PoE — indeed, LEDs cut electricity bills without Power over Ethernet — the PoE can provide additional savings in several ways. The PoE connections inherently allow for remote controls of lights. In Independence’s case, that means Martin can turn lights off or dim them in Reading from Philadelphia. “PoE is really for that automation element,”
explained Martin. “We’re able to use IT to control it. We didn’t have to install any electrical power.”

There are subtle advantages to that, too. Innovative’s Wendell Strong noted that PoE networks can be programmed to put more power into an LED light source as it gets old and starts to lose lumens. While that might sound like it would clash with energy savings, Strong explained that overall operating costs go down because early in the life of a luminaire less power is used, both saving energy and potentially doubling the lifetime of the luminaire and avoiding replacement costs.

The disconnection from conventional electrical lines, added Martin from Independence Blue Cross, is one of PoE’s biggest advantages. “You’re sticking a 2×2 luminaire in a space once occupied by an electrically wired AC outlet,” he said. “The only thing I’m doing is providing a piece of Ethernet network cable into the top of this lighting fixture. We didn’t have to install any electrical power.”

Cutting the electrical cord

Just about any PoE vendor will wax on about the benefits of the DC distribution. See our prior article on DC grids for background. Proponents note that the potential savings from eliminating conventional building wiring are enormous. Not only are the wires and the various electrical boxes costly, but they require the services of certified electricians to be installed and maintained. PoE does not and is perhaps even simpler than other proposed DC-power technologies.

In a typical PoE scenario, 120V (240V in Europe) electrical wiring terminates at the Ethernet switches — the boxes that most offices already use to plug in computers, phones, printers, wireless modems, and now LED lights and other devices to their local area networks (LANs). The switches then transmit 48V DC over the standard Ethernet cable — called Cat5 (category 5) or the newer Cat6 — a level considered safe and not in need of an electrician’s special handling.

Cisco is all in on the concept. It keeps pushing the capabilities of its Ethernet switches so that each 48V port — each place where a cable snaps in — can now furnish 60W of power, double the previous 30W, and thus doubling the number of light fixtures supported by a single port. A recent article provides a complete characterization of the power that can be carried over PoE. Cisco calls the 60W technology “Universal PoE.” The 30W variety is called “PoE+.” Early PoE switches operated at 15W.

Still, integrating PoE support in a luminaire is not absent friction. It still requires a knock down to the 12V or so that power LED light engines. But it’s a smaller job than that performed by the transformers that today turn 120V and 240V into 12V in lamps and fixtures.

Matching infrastructure and light source

Moreover, there is an added efficiency to aggregating the AC/DC conversion in one device as opposed to having that conversion happen in each luminaire. That efficiency gain can be somewhat offset by resistive current losses in the small-gauge Cat5 and Cat6 cables. Still, PoE is a net win energy-wise and, as mentioned, eliminates infrastructure and the labor needed to install it.

“If I were to take a low-voltage device like an LED and try to think up an infrastructure that I would use, I certainly wouldn’t consider having AC line voltage as my power source,” said NuLEDs CEO Chris Isaacson. “That’s been my mantra for probably eight or nine years now. If you were to develop a system to power and control LED lighting, it would not be a line-voltage AC system.”

Which probably points to a challenge facing lighting and networking companies alike in their quest to spread the PoE message: convincing the conventional construction industry — with its time-honored ties to the conventional wiring — to change its ways.

“Part of the issue with this new type of lighting and implementation right now is that you have to get the people who are building the buildings on board,” says Miami-Dade’s Karcher. “Your construction companies and your tradespeople, they have to come into it.”

That could take time. But the lesson of convergence from the media and telecommunications world should well apply: Lighting can now be digitized, portending radically new, beneficial applications for users, and potentially shaking up the status quo of vendors. Class, pay attention.

MARK HALPERis a contributing editor for LEDs Magazine, and an energy, technology, and business journalist (markhalper@aol.com).



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