The recent push toward achieving interoperability in smart grid areas, combined with entry of communications megavendors such as Cisco in the smart grid communications market, favors Internet Protocol-based communications technology and has raised interest in more ubiquitous nonutility-specific communications technology such as WiMAX.
The constant push to provide better use of assets and labor resources, combined with the need to transform the traditional energy-delivery infrastructure into a smart grid, forces utilities to consider implementing communications technologies that provide better visibility in asset performance, resource availability and end-user energy consumption.
Strategy Change
Traditionally, utility companies have considered communications technology as a component of the particular initiative, such as a mobile workforce management project, a supervisory control and data acquisition (SCADA) or distribution automation initiative, an advanced metering infrastructure (AMI) deployment or even a platform from which to venture into a commercial broadband service offering.
Although requirements for data latency, coverage scope, bandwidth, criticality and nature of transmitting information (event notification, remote control, access to enterprise applications and scheduled meter reads) as well as the ownership of the communications systems (private/public) may be different, utilities are increasingly taking a strategic enterprise approach when evaluating their communications needs.
This does not necessarily mean a one-size-fits-all approach, although, when considering AMI deployment, utilities frequently consider the use of an AMI communications backbone to support the needs for remote asset monitoring using machine-to-machine (M2M) or mobile workforce management requirements. Many vendors (such as Silver Spring Networks, Landis+Gyr or Trilliant) market their communications solutions with multiple utility purposes in mind.
The smart grid drive toward better observability of the distribution network requires SCADA-like M2M monitoring systems using different communications technologies and approaches, such as personal-area network, local area network (LAN) and wide area network. The need to support consumer energy efficiency and demand management through AMI requires a complex communications backbone, including a variety of technology — from a home-area network (HAN), mesh wireless LAN, broadband over power line (BPL) to backhaul via public communications networks.
Mobile Technologies
Because of the distributed nature of the utility asset, communication technology that needs to support utility mobile workforce management is typically provided by either commercially available cellular services — based on the Global System for Mobile Communications, general packet radio service, Enhanced Data rates for Global Evolution, wideband CDMA, 1x radio transmission technology/CDMA or 1x evolution-data optimized — or by a data channel in private mobile radio systems.
Asset Monitoring
The communications technology used to support asset monitoring and sensing with simple processing capability is usually connected as a mesh network. This provides a low-cost and robust way to distribute tens to thousands of sensors, such as active radio-frequency identification. Mesh networks are self-organizing and self-managing, and most are dynamic, so nodes can be added and removed anytime.
Advanced Metering Infrastructure
The drive toward AMI deployment has pushed traditional low-tech automated meter reading communications requirements to more complex AMI communications solutions combining several technologies. Most of the current AMI deployments include connections to a HAN (using ZigBee, HomePlug or Wi-Fi) to support consumer-based energy-efficiency initiatives and demand-response solutions. LAN (depending on population density) can use ZigBee, mesh wireless technology, star wireless technology or a wired BPL/power line communication to an aggregation point. The final leg, from concentrators (mostly at the feeder or substation level) to backhaul readings into a central repository, is usually done by a public cellular data network or a private fiber network.
The diversity of communications technologies and a lack of standards present the largest inhibitors for AMI technology selection, although some of the components, such as ZigBee for HAN and mesh wireless for LAN, are emerging as the most common solutions.
Dr. Žarko Sumiæ (zarko.sumic@gartner.com) is vice president distinguished analyst, Energy & Utilities, Gartner Industry Advisory Services.
