DOE OSTI2017
The replacement of today’s lighting infrastructure with LED products offers the potential for future connected lighting systems (CLS) that could become a data-collection platform that enables greater energy savings in buildings and cities. Such connected lighting systems can not only drastically improve the energy performance of lighting and other building systems, but also enable a wide array of services, benefits, and revenue streams that would enhance the value of lighting systems. As LED technology matures, maximizing the energy savings from connected LED lighting systems will become increasingly dependent on successful integration into the built environment. That’s why the DOE SSL Program is working closely with industry to identify and collaboratively address the technology development needs of CLS. For several years now, a growing number of wired and wireless network communication technologies have been integrated into commercially available lighting devices. While most commercially available lighting devices continue to require line-voltage AC power, a few new low-voltage DC technologies have also been introduced into the market as options for powering LED devices. More recently, a technology that has long supported non-lighting applications has become increasingly viable for LED lighting. This approach, whereby a single Ethernet cable is used to both provide low-voltage DC power and enable network communication, is generally referred to as Power over Ethernet (PoE). Whereas wireless solutions offer reduced control system installation cost relative to traditional low-voltage alternatives, PoE technology can offer additional cost savings by transmitting power and communications over the same low-voltage cable, while also reducing demand for wireless bandwidth. Although PoE technology was introduced at the start of this century, it was initially of limited applicability to lighting systems to power transmission limits for available Ethernet cabling. However, PoE has become increasingly viable for lighting applications in recent years as Ethernet cabling technology has evolved and relevant standards and specifications have adapted. These gains have been compounded by ongoing improvements to the luminous efficacy of LED technologies, increasing the number of LED luminaires suitable for use with Ethernet switches capable of sourcing PoE. As a result, a growing number of manufacturers have introduced PoE lighting systems in recent years. Connected lighting systems that can report their own energy consumption can deliver increased energy savings over conventional lighting solutions by facilitating data-driven energy management. PoE technology has the potential to be key in bringing this capability to mainstream lighting applications. This study is the first of a multi-part effort to explore the energy reporting capability of commercially-marketed PoE connected lighting systems. It first provides a brief background on the development of the various PoE technologies, ranging from standards-based to proprietary, and illustrates the convergence of PoE power sourcing capabilities and LED luminaire power requirements. It then classifies PoE system devices in relationship to how they are used in systems—introducing new terminology as needed—and briefly describes different PoE system architectures implemented by various lighting manufacturers. A discussion of existing standards and specifications that address energy reporting is provided, and existing test setups and methods germane to characterizing PoE system energy reporting performance are reviewed.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗