Why Smart Grid?
Smart Grid: Enabling the Smarter Home
The Smart Grid allows the delivery of electricity from producers to consumers that includes two-way digital communications for control and monitoring of the entire grid, from the utility to the Smart Home, which includes intelligent devices such as appliances, heating, ventilating, and air conditioning (HVAC) systems, and plug-in electric vehicles (PEVs). The overall goals are energy conservation, cost reduction, enhanced reliability and transparency, and the resulting, energy-efficient Smart Home.
A key element of the emerging smart grid is deployment of computer intelligence and networking communications over a heretofore “dumb” electricity distribution system. Efficient and reliable two-way end-to-end communications form the backbone of this intelligent grid. Therefore, the “smart grid” term can include both hardware and software added to the utilities power and communications systems. “Smart home” refers to the intelligent home’s appliances and the consumer benefits derived from the combination of the smart grid with home systems and appliances having intelligence and communications capability.
Two of the major goals of the smart grid infrastructure are to enable quick, autonomous response to events that impact the electrical power grid and establish a management system that yields optimal day-to-day operational efficiency of electrical power delivery. Utilities are concerned (and consumers are impacted) by events that influence the grid such as outages (scheduled and unscheduled), load-balancing and peak-shaving.
To address these issues, the envisioned smart grid must have the capability to: meter and monitor the power system; communicate the conditions of the grid in real time; and control the flow of power to maintain reliable service and stable operation. In developing a smart grid infrastructure, it is also necessary to design for security protocols, the inclusion of renewable-based systems (including wind, solar, and biomass sources and full electric or hybrid electric vehicles that will be plugged into the home’s electrical system), and implementation of new capabilities. These new capabilities include time-of-use or demand-driven pricing along with consumer monitoring and control of their own electric consumption.
Consumer Benefits of Smart Grid
Smart Grid deployments and trials to date have demonstrated the powerful potential for consumers to actively participate in energy conservation and to significantly reduce their overall electricity usage. Enhanced monitoring and control not only gives users the tools to improve their own energy efficiency, it drives participation in programs such as time-of-day pricing that lowers costs for users while aiding load-balancing for utilities. It also lays the groundwork for consumers to participate in peak-demand shut-down programs that provide pricing incentives to users who allow the Smart Grid to automatically curtail electricity usage by non-safety-critical in-home devices during spike demand situations. As other new electricity demands arise, such as the need to recharge electric vehicles during non-peak periods, the two-way communication capabilities between the Smart Grid and the Smart Home will also make it possible to efficiently integrate these new requirements, while maintaining optimal load-balancing throughout the overall utility grid.
Home Area Network vs. Wide Area Network The success of any Smart Grid deployment, then, will depend largely on the robustness, reliability and interoperability of the underlying communications technologies deployed for both Wide Area Networking (WAN) and Local Area Networking (LAN) throughout the system “from turbine to toaster”. Generally, the utility side (from the electricity meter outward) can be referred to as the backhaul WAN and the consumer side (the LAN within the home) is referred to as the Home Area Network (HAN).
The “Smart Meter” is the nexus between the WAN and HAN networks. The smart meter will use WAN technology to communicate up to utilities and their control centers. The smart meter also uses HAN technology to communicate into the home to all electric-powered systems and appliances made “smart” by adding communications capability.
The SHAN, or Smart Home Area Network, is thus the last critical link in the Smart Grid communications chain. Many electrical systems and appliances must necessarily become HAN peripherals. The market for SHAN technologies is therefore very attractive. Competitive HAN technologies will offer:
- Low-power consumption
- “Whole-home” coverage to connect all electricity-using devices within the home
- Reliability and robustness
- Certified conformance to industry-wide standards
Requirements for a Successful Smart Grid/Smart HAN Technology:
Reliable communications for a diverse set of consumer devices. One major difference between the WAN and HAN is the degree of control that the utility can exercise over the networking and communications environment. Utilities essentially can decide for themselves how best to implement communications across the WAN. However, the Smart HAN is an entirely different situation, in which a wide range of devices selected by consumers must be able to communicate seamlessly to the Smart Grid. Therefore, it is critical that Smart HAN communications be based upon widely-accepted and well-controlled standards, with verifiable certification mechanisms to assure reliability and interoperability of all connected devices.
Compatibility with other in-home networking applications. In addition, Smart Grid communications within the SHAN also must co-exist compatibly and seamlessly with other home networking functions, such as audio-visual entertainment content, IPTV, interactive gaming, etc., without degrading or interfering with these consumer applications. Effective coexistence is a critical factor when implementing both Smart Grid and other home-based network applications using powerline technologies.
Ubiquitous networking is critical for the Smart Grid. In order for the Smart Grid to deliver on the promise of comprehensive in-home energy management, it goes without saying that the SHAN needs to include all of the major devices using electricity throughout the residence. In order to achieve comprehensive coverage throughout all types and ages of residences (old, new, single-family, condos, etc.), it’s also important that the selected Smart Grid communications technologies operate reliably either over-the-air or over existing electrical wiring.
Low-cost and low-power are fundamental for “green” networking. Another critical factor for achieving ubiquity in Smart Grid networking will be solutions that can be efficiently implemented in every category of smart grid-enabled devices found in homes and small businesses. This requires a complete network interface (PHY and MAC) that is optimized for both low-cost and low-power, along with clear standards-based documentation to support embedding of the interface within any device.
Both wired and wireless approaches are needed. From the beginning of the Smart Grid development, utilities and their equipment suppliers have recognized the need for using both wireless and wired networking approaches. While wireless solutions play a role in the Smart Grid, the signal propagation and physical barrier issues that are inherent with any wireless approach make it appropriate to offer alternatives such as power line communications. As discussed later, the Smart Energy Profile 2.0 addresses this issue by providing a common application layer enabling interoperability between the leading standards-based technologies for both wireless and wired Smart Grid/Smart Home technologies.
HAN Standards Report, Association of Home Appliance Manufacturers (AHAM):
The AHAM issued a 37-page report entitled “Assessment of Communication Standards for Smart Appliances: The Home Appliance Industry’s Technical Evaluation of Communication Protocols” (October 2010). This report details industry research on various communications standards for use by smart appliances. The industry defines a smart appliance as “a product which has the capability to receive, interpret and act on a signal received from a home energy management system, utility, or third party energy service provider, and automatically adjust its operation depending on the signal’s contents and settings from the owner.” AHAM is concerned that there be national standards to ensure that an appliance can connect anywhere in the U.S., wherever the Smart Grid infrastructure is available.
The evaluation included assessment of standards for the Application (APP), Network (NET) and Media Layers (MAC, PHY). Across the media and network layers the group evaluated, HomePlug Green PHY scored highest for powerline along with Wi-Fi and ZigBee for wireless technologies. The technical assessment “finds that these application protocols, and the media capable of delivering them, are the best performing protocols for Smart Grid targeted applications for a consumer audience.”
The HomePlug Powerline Alliance’s Green PHY specification (approved and published June 2010) is an optimized-for-Smart Grid powerline technology based on the widely adopted and carrier-proven HomePlug AV technology. Both HomePlug AV and HomePlug Green PHY are interoperable and compliant to the recently ratified IEEE 1901 global standard.
- Association of Home Appliance Manufacturers (AHAM) Smart Grid homepage: View link
- HomePlug Green PHY Overview: View link
- HomePlug Green PHY Whitepaper: View link
- U.S. Department of Energy, Office of Electricity Delivery and Energy Reliability website: View link
- (U.S. DoE) The Smart Grid: An Introduction (PDF); a 48-page booklet intended for the non-technical reader covering the need and benefits of a smarter electrical grid and what the application of such means for the U.S.: View link
- National Institute for Standards and Technology (NIST) Sources: NIST Smart Grid Interoperability Standards Project: View link
- NIST Framework and Roadmap for Smart Grid Interoperability Standards, Release 1.0: View link
- Electric Power Metrology and the Smart Grid homepage: View link
- Electric Power Research Institute (EPRI), Smart Grid Resource Center: View link
- Federal Energy Regulatory Commission (FERC) Smart Grid homepage: View link
- Blog: Consumer Interface with the Smart Grid; Office of Science and Technology Policy (OSTP): View link