DC Current Making a Major Comeback, National Lighting Bureau Experts Say

DC Current Making a Major Comeback, National Lighting Bureau Experts Say


Walk around just about any office in the United States and you’ll see dozens of power modules — point-of-use power transformers — plugged into conventional alternating-current (AC) electrical outlets, transforming the incoming AC to low-voltage direct current (DC), for use by telephones, tablets, laptops, and other electronic devices, including light-emitting-diode (LED), electric-illumination installations. Now, lighting-system manufacturers are heading forward to the past, bringing DC circuitry — called “power over Ethernet” or PoE — to the office and other workplaces, so point-of-use power transformation will no longer be required. Two experts discussed PoE at the National Lighting Bureau’s Annual Lighting Forum during a session called “Illuminating the Future, Part One.” The two experts were: Lisa L. Isaacson (NuLEDs), and Michael S. “Mike” O’Boyle (Philips Lighting).

EdisonReport Editor and Publisher Randy Reid moderated the panel. The video is now available free from the National Lighting Bureau.

According to Isaacson and O’Boyle, PoE differs from conventional DC networks in that the cabling used can carry both power and communications signals, much as a smart phone that receives both power and communications signals when it is connected to a computer via a universal serial bus (USB) connector.

Being able to rely on one cable network for all connected devices permits connected devices to communicate with one another, evolving into an “Internet of things” (IoT) inside each building where the technology is used, and to communicate with other systems and other buildings, to as wide an area as desired. It also enables users to communicate with their lighting, using a smart phone and an app, to increase or decrease the amount of electrical illumination being provided, or to change the color of its output.

The panelists noted that PoE will not eliminate the need for conventional AC circuitry, but it will eliminate the need for AC power transformation when it comes to power for electronic devices. Both panelists also expressed confidence that PoE will likely be installed routinely in the near-term future, not only because of the versatility it provides, but also because it is safer to handle: Line-voltage AC can cause fatal accidents; low-voltage DC is much safer. PoE systems will also become less costly to install, Ms. Isaacson said, because less installation labor is involved. Right now, the cost to install a conventional system or a PoE system is about the same, because PoE’s installation-labor savings are offset by higher equipment costs. As more competitors enter the market, and as the equipment becomes more widely available, equipment prices will fall, so that wiring a building with both PoE and AC, where needed, will cost less than wiring a building with AC alone.

Watch “Illuminating the Future, Part One” free of charge at https://nlb.org/lighting-forum-videos/.

The National Lighting Bureau is an independent, IRS-recognized not-for-profit, educational foundation that has served as a trusted lighting-information source since 1976. The Bureau’s services are provided to the public free of charge, thanks to the generous funding of the organization’s sponsors: professional societies, trade associations, labor unions, manufacturers, and agencies of the U.S. government, including: Current, Powered by GE; Forest Lighting; Illuminating Engineering Society (IES); Imperial Lighting Maintenance Company;  interNational Association of Lighting Management Companies (NALMCO); International Brotherhood of Electrical Workers (IBEW); Lighting Controls Association (LCA); LumenOptix; Lutron Electronics Company, Inc.; Luxtech; National Electrical Contractors Association (NECA); National Electrical Manufacturers Association (NEMA); OSRAM; and U.S. General Services Administration.

Obtain more information about the Bureau by visiting its website at: www.nlb.org.


Related Posts