This piece is from the author of GTM Research's new smart grid report, Distribution Automation Communication Networks: Strategies and Market Outlook, 2012-2016, offering insights and perspectives on the U.S. market for the communications networks that enable distribution automation.
Utilities now looking to automate their distribution grids ought not repeat the mistakes made by some AMI deployments by designing it as just one more hardware overlay. Instead, future programs and especially communications should be designed within the context of a network using state-of-the-art information and data management technologies. That’s one of the key messages in the recent GTM Research report Distribution Automation Communication Networks: Strategies and Market Outlook, 2012-2016. In fact, the report finds that ”implementing and obtaining the benefits of DA programs requires access to new communications networks that do not now exist within most distribution grids. In addition, the design, engineering, implementation and operation of these systems require intellectual resources and competencies that are usually associated with IT operations, not electric utilities.”
Thus far, we’ve seen a number of situations where AMI systems have been installed by utilities using purpose-built communications systems, systems that are not going to be adequate to support DA and other more sophisticated technologies over the long term.
Last week, a LinkedIn discussion group had a topic listed as “The Case Against the ‘Smart Grid’.” What had been posted for comment was a YouTube presentation by Bruce Nordman at Lawrence Berkeley Laboratory. Although three years old, the presentation makes a number of points that build upon the findings in the GTM Research report. One of Bruce’s arguments is that semantics are important because they frame the thinking behind system design. Defining the “smart grid” as encompassing everything from power plants to end-use devices drives thinking to a mix of networking concepts with hardware concepts.
Without a clear separation between the two, such thinking can distort network design and allow ancient control paradigms to flourish. This hardware-centric focus distracts attention from the real grid and limits the understanding of its broad potential. The focus ultimately was on building systems, but its observations were quite prescient when we look at what happened to AMI.
In many AMI systems deployed to date, the meter was regarded as the end-use device, which was sometimes connected to a home area network. AMI-unique communications were installed to periodically talk to the meter and deployed to meet the requirements of that metering system, most likely using the least-cost option. What the GTM report identifies -- and which Nordman amplifies -- is the fact that the distribution system constitutes one domain, the home network another domain and the meter the interface between them. Further upstream in the grid, the distribution domain interfaces with a number of other domains that include substations, transmission, business operations, customer data and the overall enterprise network. Unfortunately, this longer-term perspective has been the exception rather than the rule in many programs.
It’s not hard to understand why we ended up with meter-centric “smart grid” programs. Meters are easy to describe, customers can see them and billions were paid out to implement meter programs. Presumably that’s one of the reasons why the Department of Energy chose to invest billions in meter programs, rather than to gain the larger and more immediate returns from invisible distribution and transmission infrastructure automation investments. Nonetheless, this hardware focus distorted the transformation of the grid to a network and, because of its difficult business case, has made it harder in some regulatory jurisdictions to gain rate recognition of DA programs.
Regardless of whether or not a utility has an AMI network, the opportunity exists to design its next steps within the proper context and with the longer-term view. At present, that’s an IP-based networking system that connects the application and physical layers in a distributed, universally interoperable network. The GTM report noted as much in its recommendation that utilities adopt the OSI Layer model in network design. Key to the flow among layers and interoperability is the common layer: Internet Protocol, as shown in the figure below.
FIGURE: DA Communication Article Figure
Source: Distribution Automation Communication Networks (GTM Research)
As the report notes: “Internet Protocol (IP) networking frameworks are becoming the baseline for smart grid communication networks and are likely to be the only realistic path to achieving interoperability within the system.”