The minimal power requirements of LED lighting fixtures have paved the way for innovative low-voltage lighting infrastructures where luminaires are powered by nothing more than a single ethernet cable. Although the use cases are limited at present, there is a significant potential for power over ethernet (PoE) lighting to bring intelligence to buildings and opportunity for low-voltage installers.

PoE can connect, monitor and control LED light fixtures and a host of sensors and devices that keep a building running, such as HVAC, occupancy and access control, all in a single network. When used to its full potential, PoE lighting could reduce the cost of operating lighting by as much as half, boost a building’s sustainability and provide intelligence. But adoption has been spotty, in part because of the minimal power provided, some lack of interoperability and the challenges around integrating electrical and IT worlds.

The technology has been evolving to address the basic challenges. The first PoE lighting systems were a mere 30W per fixture, which is not enough to illuminate a room. In 2017, the wattage was increased to 60, while higher-performance PoE can reach as much as 75W or 90W. With this higher wattage, PoE became a legitimate, viable lighting source. In fact, 60W or 75W “is plenty of light for your typical commercial application,” said Carol Jones, vice president of integrated systems development at Axis Lighting, LaSalle, Quebec. High-output fixtures in a tall ceiling may require more power, but in a typical commercial application, it’s enough, she said. Therefore, new independent PoE manufacturers have been developing products.

PoE evolution

Since the earliest PoE solutions were developed, first by Cisco, San Jose, Calif., to provide power to voice over internet protocol (VoIP) phones, PoE’s higher power ratings have provided more options for usage, said Haider Abbas, IT project manager at Houston-based LED Industries.

Cisco developed and first delivered a proprietary version of PoE in 2000 to enable scalable and manageable power delivery to Cisco IP-telephony handsets. This early version delivered just 10W, said Jeffrey Meek, Cisco’s product marketing manager for enterprise networks. PoE has gone from powering VoIP phones, to IP cameras, to laptops, and now to lights for a whole office building or hotel, he said. And PoE removes the need for power wiring, as the ethernet cable provides data and power.

PoE also provides unique benefits, including data gathering, trend analytics and the flexibility of control provided by managed switches or gateways. And by bringing lighting into the IT closet where other low-voltage systems exist, facility managers can combine their energy monitoring and building systems with lighting control. There are multiple considerations that a contractor or integrator will have to address when installing such a system, however, said Mike Starr, founder and electrical engineer at Nebulous LLC, Madison, Wis.

POE lighting leverages switches with multiple ports—as many as 24 or 48—dedicated to fixture connections. The ports depend on the IEEE 802 standard they are listed for, Starr said. According to the National Electrical Code , a PoE switch can plug into 120V of power, and the ports can then feed power directly to fixtures according to the wattage allowed per port. So a PoE switch (or multiple switches) for LED fixtures could address lighting at an average site for office or commercial use. The average flat-panel LED light fixture, for instance, ranges 10W to 50W, Starr said, depending on the application and size.

Consider the example of a 30,000- square-foot office building, Starr said. At 0.5W of lumens per square foot, such a system could operate with 5–10 dedicated switches in the tech closet, thereby requiring one more rack there. So another consideration is accommodating that lighting network in the IT closet.

“Such blending of data and electrical systems can also further mix the roles of trades (electricians) or technology (IT) staff,” he said.

Myths and realities about PoE

There are some misconceptions about PoE lighting, foremost is the idea that such an installation can be done without an electrician.

“That’s a bit of a myth. You can’t get away with doing a quality lighting project without having an electrician install your fixtures,” Jones said, adding that IT solution providers do not have experience with the wide variety of fixture types included in most lighting deployments. “They come from different disciplines and have different competencies.”

Meanwhile, those who deploy this low-voltage lighting experience a variety of benefits. One is a reduction in energy consumption, as much as 50%, and the other is a matter of intelligence. By gaining data about the lighting, having control over light settings for each fixture and integrating with other building systems, the savings over time can be significant. PoE enables TCP/IP communication—networking data to and from a server, which delivers data about many types of devices at a time—where there is already an overall trend toward digitalization. Jones predicted that in the long term, digital data will be a must for most buildings.

“Whether it’s wireless digital lighting sensors or PoE, building owners and managers are going to find a way to digitize their lighting along with other building systems. It’s just beneficial for too many reasons.”

Many office building tenants have already gotten a taste of what connectivity can provide them with apps, which are often directed at those who spend their workdays at large corporate sites. Tenants may use apps to access the building through their phone or use it for wayfinding to conference rooms, updates on deliveries to the building and reminders that the on-site yoga class begins in half an hour.

“Those are location-specific things that are starting to become real with these tenant-experience apps,” Jones said.

PoE serves as a complement to such digitization, especially for building or company management. Consider a few of the options that have been tested with PoE lighting and sensor systems: occupancy sensors connected to PoE fixtures can communicate real-time location information for use with an HVAC system to fine-tune temperature levels. From that point, a variety of other options could enter the mix. Consider PoE- connected elevators, cameras and security access systems responding to PoE fixtures that communicate the presence of people in different areas of the building.

However, there are a few key points to consider. The low-voltage system should be designed to use all the wattage available and portion it out according to each port’s demand, thereby reducing the number of servers required. Jones said Axis is among the companies that have designed a system to support maximum use of wattage per port.

There are cable considerations, as well. With PoE, cables can’t run too long; according to the Department of Energy, a maximum of 50 meters between the fixture and PoE server switch will result in loss of 5% or less.

Installers must also know about and choose products that meet testing requirements. Fixtures with integral PoE components must meet UL2108 standards, even though they are powered from a low-voltage source. Not all manufacturers have completed this testing, so it’s important to verify that fixtures have been tested, Jones said.

Proven results

Early examples of PoE lighting systems are deployed at many commercial and architectural environments. Some of LED Industries’ past projects include the Sinclair Marriott hotel in Fort Worth, Texas, which is running almost completely on PoE, Abbas said. Cisco’s New York office at 1 Pennsylvania Plaza has also shifted to PoE power.

Some users are attracted to PoE low-voltage lighting’s safety, Abbas said.

“One can touch the bulb socket directly and all they would get is a static shock at best, since the voltage is 48V at max and 24V at an average,” he said.

Even if the connection comes in contact with water, it’s not as life-threatening as regular line voltage.

The clean-energy benefit goes beyond reduced power consumption, Abbas said. It uses 60% less copper than a line-voltage installation. The flexibility to control and schedule the lights provides a major boon to any PoE setup. Some companies are using the PoE systems to schedule the light to follow the circadian rhythm and positively affect the mental health and productivity of the people in the lighting space.

Others in the industry agree. PoE has already been a staple in offices worldwide, Meek said, and up to 90W capacity opens the door to new options, such as powering security systems and pan-tilt-zoom cameras, monitors, window shades and even air conditioners and refrigerators.

“In the long term, as circumstance meets need, interest in smart building technology that includes PoE lighting has only accelerated” as many look to transition to healthy hybrid work environments, Meek said.

For manufacturers and designers, the technology still depends on further education of the lighting industry.

“Most people don’t really understand how PoE works and, based on that, don’t give it the time of day,” Abbas said. “LED Industries strongly believes that PoE is the future, and the more people that know about PoE and its capabilities, the more everyone would benefit.”