The Power of PoE

By Susan Bloom | Jun 15, 2015
Electrical Contractor Power Over Ethernet 2.jpg




Power over Ethernet (PoE) is any of several standardized or ad-hoc systems that pass electrical power along with data on Ethernet cabling. These systems enable a single cable to provide both data connection and electrical power to such devices as wireless access points, phone systems, Internet protocol (IP) cameras and light-emitting diode (LED) lighting. An approach that’s become an increasingly efficient medium for power delivery to a range of a building’s low-voltage systems, PoE-driven applications are delivering cost savings, ease of installation and enhanced flexibility to qualified projects. 

For electrical contractors, the technology offers a wealth of opportunities to streamline building infrastructure, enhance efficiency and provide value-added expertise and services. Here, several industry experts offer insights into the use and benefits of the growing PoE methodology and encourage contractors to become familiar with this increasingly popular and viable platform.

The PoE platform defined

“PoE refers to the use of some number of wires that are part of a structured cable, usually Category 5 cable, for the delivery of electrical power, in addition to its original intended use as a communications carrier,” said Paul Savage, CEO of Detroit-based Nextek Power Systems and founder and chairman of EMerge Alliance, which promotes the adoption of safe direct-current (DC) power distribution in commercial buildings. 

“Unlike Class 1 power levels, which must be handled by licensed electricians because the voltages they carry can be lethal, PoE voltages are ‘Class 2’ at less than 60 volts [V], below the shock and startle hazard,” Savage said.

Among the benefits of this approach (two popular techniques of which are currently standardized by IEEE 802.3), “Class 2 cabling doesn’t need conduit or metal cladding, so it installs faster and can be rerouted easily and safely,” he said.

Jim Filanc, director of business development for Southern Contracting Co. in San Marcos, Calif., agreed.

“You might have five, six wireless access points over 10,000–15,000 square feet of space, and the installation of wiring over this power run often involves the expensive and time-­consuming process of opening up walls and using extensive cabling,” Filanc said. “Because it allows long cable lengths, PoE eliminates the need to hard-wire wireless access points and is great for pushing sufficient power out to eligible appliances—along a long hallway, for instance, to operate a stretch of security cameras.”

This approach isn’t necessarily new.

“PoE, as a technique implemented in traditional IT and data networks, emerged 20 years ago,” said Jim Sekinger, Smart Lighting Go-To-Market and Technologies Consultant and founder and managing director for Ad Astra Consulting, Chicago. “At that time, the maximum amount of power that PoE technology could support was very low, just 7½ watts [W]. But, as it matured through the 1990s and 2000s, it became more powerful, enabling the replacement of old coaxial cables in security systems and the upgrade of outdated PBX wiring in telephones to voice over IP systems in buildings.”

Thanks to recent advancements in both PoE and LED technology, these lighting systems—which are increasingly popular among building owners—have become the newest candidates for the PoE platform.

“Traditionally, buildings have had to run 120V or 227V power to support conventional high-voltage lighting systems involving fluorescent technology, which required junction boxes, relay panels, cables, conduit, and many other components,” Sekinger said. “But, as PoE systems have evolved to support 60W of power today, and LED systems have become increasingly efficient—for example, many LED troffer configurations that consumed 40–50W two years ago require just 30–35W today—LED lighting is a low-voltage system that’s now fully able to benefit from the power of PoE.”

John Kruse, senior design and development manager at Montgomeryville, Pa.-based LumenOptix, said the proliferation of LED lighting means PoE now has more uses than ever.

“Because the power limits of LED are low enough, PoE enables the use of one cable from the load panel to each fixture; you can run one wire to fixtures, sending power and control signals down the same wires and driving an easier and safer installation process,” Kruse said.

Jay Goodman, founder of LumenOptix, further described the relationship.

“Power comes through the lighting fixtures from an IT switch over regular Ethernet cables as opposed to coming from a building load panel, and this compelling medium offers enough power to deliver dimming signals, occupancy sensing/lighting control and even two-way communication,” he said.

Possibilities and limitations

“PoE combines power and control onto Ethernet (eliminating the need for separate power lines), links the lighting and other building subsystems together, and further connects all of these to the cloud to enable myriad imagined and as-yet unimagined software-enabled services,” Sekinger said.

Optimal in a range of data center applications, where miles of Ethernet cables already exist, as well as in a variety of commercial office and healthcare settings, “a network exists on PoE that can deliver massive amounts of information about the building based on data generated by the lighting system. This can include information on movement, temperature and other elements of a ‘smart building’ to information on the health and human-centric impact of lighting, and, theoretically, can evolve into a ‘Li-Fi’ system that replaces Wi-Fi in retail settings, whereby a wireless network uses lights to communicate information (or send targeted coupons, for example) to customers’ smartphones,” he said.

PoE delivers benefits by way of lower installation and 
operating costs.

“There’s a minimum of 15 percent savings in total cost of ownership over a 10-year period utilizing LED lighting, controls and PoE, a number that can be greater depending on the type of system it’s being compared to as well as how you use the lights—e.g., whether you install a control at every fixture,” Sekinger said.

Goodman said that, through PoE, contractors will also benefit from a far less-complex installation process, especially in areas where fixtures are difficult to access. 

“You can pull these cables more easily because you only need to pull a single wire, and the use of PoE may also simplify the permit process because this falls under IT wiring,” he said.

At the same time, experts are quick to note the limitations of PoE as it relates to eligible appliances like lighting. Among those, “PoE has limits as to the amount of power it can transmit, which are generally never met by Class 1 wiring,” Savage said.

Sekinger said that other issues with PoE today involve “efficiency losses in delivering power to the fixture, though the savings PoE drives more than offset this concern and technological advancements are helping PoE to become even more efficient while reducing line losses.”

Still, Kruse agrees that this downside currently renders PoE less suitable for certain applications.

“Running a high-powered application such as a fluorescent fixture at the end of a 300-foot-long cable results in a noticeable loss of power and efficiency,” Kruse said. “For shorter runs where you have access to nearby IT cabinets or where you want individual control over low-voltage lights like LEDs, however, PoE makes sense.”

According to Sekinger, the compatibility of components currently represents another issue that contractors have to contend with when evaluating the feasability of PoE.

“PoE requires compatible nodes or drivers that sit on the fixture or are mounted separately, and some fixtures are outside of the bandwidth of PoE drivers today,” Sekinger said. 

Among the group’s recommendations, Filanc urges contractors to follow local wiring codes to ensure that they’re not putting an excessive load on the Ethernet cable and creating a fire hazard, while Savage feels that contractors need to gravitate toward UL-listed systems and not assume that “low-voltage” always means intrinsically safe.

A bright future

Those considerations notwithstanding, industry experts say that the future looks bright for PoE when applied properly.

“It’s not a matter of if it’s going to happen, but a matter of when, and we encourage contractors to familiarize themselves with PoE and get involved with projects that involve this platform,” Sekinger said.

In addition to several large data-component and lighting manufacturers promoting PoE (such as Philips Lighting), there are a few startups making LED fixtures for PoE sources. 

“At Nextek, we’ve powered PoE injector-type power supplies from our system in addition to holding some relevant patents in this area based on our tenure and experience in the DC-power-systems space,” Savage said. “PoE is a fact of life that’s becoming increasingly pervasive. Many electrical contractors already have ‘low-voltage’ divisions to capture this business, and I believe we’ll see more and more of this.”

Many believe PoE will only grow in popularity.

“From a technological standpoint, the more PoE is adopted, the more companies will develop products for it,” Kruse said of the bright R&D horizon for this platform.

Goodman also voiced his agreement.

“While PoE is a completely different architecture, it represents a phenomenal opportunity for the existing and established lighting channel of agents, specifiers, contractors and distributors, as well as some new IT players, to expand their market basket of tools,” he said. “We urge them to embrace it.”

Filanc said that the technology will eventually take over entire buildings.

“With the growing demand to retrofit commercial buildings, PoE technology will be helpful, and we’re not just talking about better lighting or AC, but about full-building automation,” he said. “For buildings containing multiple floors with multi­purpose uses, building owners and contractors should look at the data infrastructure and consider the use of PoE from a cost and value-engineering perspective as it applies to systems like VoIP, security cameras with pan-tilt-zoom capability, LED lighting, and other wireless access points. If facilities need or use these technologies, PoE can be a great option and a technology that really extends a contractor’s reach.

“With today’s systems requiring so many appliances, it’s the perfect time for electrical contractors to consider a PoE upgrade to ensure that their customer’s building is ready for the 21st century,” Filanc said.

For more information on PoE, join the ‘Intelligent Lighting Network’ on LinkedIn at­Intelligent-Lighting-Network-4390496/about or visit the EMerge Alliance at

About The Author

BLOOM is a 25-year veteran of the lighting and electrical products industry. Reach her at [email protected].





featured Video


New from Lutron: Lumaris tape light

Want an easier way to do tunable white tape light?


Related Articles