Communications Update–Data Standards for Home Energy Management, Renewables Integration

By Wei-En Tan, Tropos Networks

During April’s GreenNet conference in San Francisco, a keynote session panelist made a statement that echoed as a conference theme: The world’s not waiting for the next best technology in smart grid. We already have it, and our technology is fairly advanced.

What’s next in the smart grid landscape and how fast we’ll move to full implementation is a matter of standards, standards and standards. In addition to the standards debate, I would add regulation, regulation and regulation, but his point is well-taken. As networking and information technology standards were essential to the Internet’s mass adoption, likewise, standards will be necessary to ensure a smooth transition to the intelligent grid.

So what is happening on the standards front? In January the National Institute of Standards and Technology (NIST) issued Release 1.0 of its “Framework and Roadmap for Smart Grid Interoperability.” Release 1.0 is the first phase of a three-part plan NIST designed to identify and initiate adoption of a set of standards necessary for smart grid conformity, interoperability and certification. The second phase involves public-private partnerships with the goal of evolving the road map to ensure ongoing coordination and eventually implementation. The last phase is the testing and certification stage, where implementation will begin in 2010.

In Release 1.0, NIST identified 75 standards and specifications applicable to the “ongoing transformation of the smart grid,” as well as 15 priority areas of further investigation. More than five months after the road map’s release, what developments have been made in compliance and implementation? NIST’s Smart Grid Interoperability Panel (SGIP) implemented taskforces to begin setting compliance standards. The SGIP is a public-private partnership initiated by NIST to speed development of interoperability and cybersecurity standards for a nationwide smart electric power grid. They have defined 16 priority action plans (PAPs) that range from wind plant communications (added late May) to power line carrier standards and designated committees for each plan. As this process continues and bleeds into phases two and three, what does this mean for the industry? Did certain standards lose out? Many debates exist in all areas of communications standards; however, examining all 75 standards and priority areas would be tedious. Two specific areas have seen interesting development: home area networking (HAN), including the ZigBee-Wi-Fi Alliance partnership, and data standards for the grid integration of renewable generation.

Wireless Protocol Giants Unite–When ZigBee Meets Wi-Fi

On the heels of the NIST road map that included and identified ZigBee (underlying IEEE 802.15.4 specification) as well as Wi-Fi (IEEE 802.11,) the ZigBee Alliance and Wi-Fi Alliance announced March 17 that they would develop collaboratively interoperable applications for home energy management and applicable devices.

Many established wireless communications technologies operate in frequency bands shared among several users, often using different radio frequency (RF) schemes. This is true for Wi-Fi, ZigBee and Bluetooth. All three operate in the unlicensed ISM or 2.4 GHz band, which has encouraged a competitive market for wireless embedded devices. In particular, ZigBee is an attractive technology in smart grid HAN, which requires implementing low-cost, low-power wireless control networks requiring high flexibility in node placement, whereas Wi-Fi has been the mainstay of laptop computers, personal smart devices and so forth.

Even prior to interoperability issues among smart grid HAN devices, other wireless technologies in the same ISM spectrum had raised concerns about potential coexistence issues. Wi-Fi traffic could interfere with ZigBee operations despite ZigBee’s occurring at a lower power level. These technologies must coexist peacefully to allow each user of the band to fulfill its communication goals. The recent ZigBee and Wi-Fi partnership will enable interoperability among devices with the different technologies. It will be easier for appliance makers to comply with the NIST Smart Energy 2.0 open standard for smart grid devices, and consumers can choose their appliances knowing they can communicate with each other.

Camille Ricketts, lead writer at GreenBeat, wrote in an article that the partnership between Wi-Fi and ZigBee might be more of a “survival pact” than anything else, as unpopular protocols get eliminated in favor of protocols that have garnered support among users through compliance with the Smart Energy 2.0 standard. The interoperability pact between ZigBee and Wi-Fi is one of the mile markers of an industry that is moving into its next phase of maturity. Moreover, open standards and interoperability also mean a more level playing field, possibly meaning more or quicker innovation and technological advances.

Recently in more HAN news, the SGIP reported major developments toward a standardized format and foundational data structure for communicating information on household energy consumption. By the end of 2010, the North American Energy Standards Board (NAESB) will construct a basic energy usage data model standard to structure how consumption information is organized and communicated between utilities and customers. The data model will combine components of information, and the standard will enable utilities and consumers to communicate energy use and cost through a consistent data format.

Data Standards in Renewables

Besides increased energy efficiency, conservation and transmission, one smart grid benefit is the ability to smoothly integrate energy generated from renewable sources such as wind and solar–which are highly unpredictable and intermittent–into an existing transmission and distribution cycle. Not mentioned specifically in the NIST road map is applicable data standards for generation from renewable sources, which falls under a more general transmission and distribution area. Nevertheless, renewable generation deserves special attention because it is poised to become an integral part of the energy mix. The percentage of renewable sources in the total amount of U.S. energy generated already has increased exponentially. According to the monthly electrical power report, in April 2009 electricity from renewable sources accounted for 12.97 percent of the total electricity generation. The percentage only will increase because many utilities must meet renewable energy portfolio standards (RPSs.) For example, California retail energy sellers must purchase 20 percent of their electricity from renewable sources by 2010. Similarly, 5 percent of Texas’ electricity demand must be generated from renewable sources by 2015.

Because of these state mandates and economic stimulus specifically for renewable generation, utilities are planning or have brought thousands of megawatts of electricity online from renewable sources. This underscores renewable generation challenges. Renewable generation unpredictability makes load management, spot market pricing, forecasting and implementation difficult. The solution is to integrate information technology and smart systems to manage performance, anticipate and correct. Just as data standards for HANs, advanced metering infrastructure networks and transmission and distribution are developed and established, data standards must be developed for renewables integration to ensure that manufacturers and vendors can adhere to compliance demands and enable interoperability among compliant technologies. These systems will necessitate data standards as they begin to scale.

With SGIP’s May announcement of the wind plant communications PAP, it appears that more attention is being paid to specific standards for the renewable energy industry. International standards for wind power plant communication exist, but they have not seen widespread U.S. adoption, and a large percentage of wind plants use proprietary technology and legacy protocols.

Besides the PAP from the SGIP, the first agency to develop data standards specifically dedicated to renewable energy is the SunSpec Alliance, an industry consortium of manufacturers, system integrators, vendors and interested agencies. On June 7, The ZigBee Alliance and the SunSpec Alliance announced an agreement to collaborate on defining standards for renewable energy and microgrid management using the ZigBee Smart Energy version 2.0 standard. The SunSpec Alliance is publishing a series of specifications initially built upon Modbus standards. Modicon established Modbus in 1979 for use with its programmable logic controllers (PLCs) and is a communications protocol that has become standard for connecting industrial electronic devices. The SunSpec Alliance’s initial aim is to integrate distributed photovoltaic (PV) power generation systems cost-effectively and on a large-scale basis. Although this first set of specifications is intended for PV systems, using existing standards created by other agencies and standards bodies, the alliance will continue to define open interface standards for other forms of renewable energy “to interact with information technology systems in a predictable and reliable manner.”

Defining open interface standards for the smart grid, whether in HAN, renewable energy integration or otherwise, will accelerate development of a safer, more predictable grid. In energy generation, transmission and distribution, we don’t need the next, best, most innovative technology; we’re on the right track defining standards and regulations for safety and reliability. After all, the flashiest iPad or the coolest electric vehicle is useless if you can’t recharge it because of a blackout.

This article originally appeared in the July 2010 issue of Powergrid International and was updated for Electric Light & Power.


Wei-En Tan is senior director of public relations at Tropos Networks. She graduated from Stanford University with multiple graduate degrees specializing in political science, econometrics and comparative literature. She also is a commercial airplane and helicopter pilot. Previously, Tan worked as the director of technology of the cleantech practice at Antenna Group Inc. Reach her at


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