Smart Grid
editSmart grid combines traditional power hardware with sensing and monitoring technology, information technology, and communications to enhance electrical grid performance and support additional services to consumers.[1]
Overview
editThe electrical grid is an interconnected system of power plants, power lines, wires, etc. moving and delivering electricity from power plants to end users. Also referred to as a transmission and distribution (T&D) network, today’s grid faces challenges to kept pace with the modern digital economy and information age, which require higher load demands, uninterruptible power supplies, and other high-quality, high-value services. Additionally, microprocessor-based technologies can alter the nature of the electrical load and result in electricity demand that is incompatible with a power system that was built to serve an “analog economy.” This can lead to electric service reliability problems, power quality disturbances, blackouts, and brownouts. However rapid advances in communications and information technology now provide electric utilities with opportunities to invest in critical grid infrastructure that can serve the growing demand for high quality, “digital-grade electricity.”[2]
Purpose
editA smart grid can precisely manage electrical power demand down to the residential level, network small-scale distributed energy generation and storage devices, communicate information on operating status and needs, collect information on prices and grid conditions, and move the grid beyond central control to a collaborative network.[3] Table 1[4] provides a summary comparison of today’s grid with a 21st Century Smart Grid of the Future.
Table 1 - Smart Grid of the Future
20th Century Grid | 21st Century Grid |
---|---|
Electromechanical | Digital |
One-way communications (if any) | Two-way communications |
Built for centralized generation | Accommodates distributed generation |
Radial topology | Network topology |
Few sensors | Monitors and sensors throughout |
“Blind” | Self-monitoring |
Manual restoration | Semi-automated restoration and, eventually, self-healing |
Prone to failures and blackouts | Adaptive protection and islanding |
Check equipment manually | Monitor equipment remotely |
Emergency decisions by committee and phone | Decision support systems, predictive reliability |
Limited control over power flows | Pervasive control systems |
Limited price information | Full price information |
Few customer choices | Many customer choices |
Some defining functions of a smart grid include:
- “Self-healing” – Using real-time information from embedded sensors and automated controls to anticipate, detect, and respond to system problems, a smart grid can automatically avoid or mitigate power outages, power quality problems, and service disruptions.
- Empower Consumers – A smart grid incorporates consumer equipment and behavior in grid design, operation, and communication. This enables consumers to better control “smart appliances” and “intelligent equipment” in homes and businesses, interconnecting energy management systems in “smart buildings” and enabling consumers to better manage energy use and reduce energy costs. Advanced communications capabilities equip customers to exploit real-time electricity pricing, incentive-based load reduction signals, or emergency load reduction signals.
- More Secure – Technologies better identify and respond to manmade or natural disruptions. Real-time information enables grid operators to isolate affected areas and redirect power flows around damaged facilities.
- Accommodate Generation Options – As smart grids continue to support traditional power loads they also seamlessly interconnect fuel cells, renewables, microturbines, and other distributed generation technologies at local and regional levels. Integration of small-scale, localized, or on-site power generation allows residential, commercial, and industrial customers to self-generate and sell excess power to the grid with minimal technical or regulatory barriers. This also improves reliability and power quality, reduces electricity costs, and offers more customer choice.
- Optimize Assets – A smart grid can optimize capital assets while minimizing operations and maintenance costs. Optimized power flows reduce waste and maximize use of lowest-cost generation resources. Harmonizing local distribution with interregional energy flows and transmission traffic improves use of existing grid assets and reduces grid congestion and bottlenecks, which can ultimately produce consumer savings.
Technology
editSmart grid development does not require large-scale technological innovation. Many smart grid technologies are already used in other applications such as manufacturing and telecommunications. Smart grid development for the most part can use existing technologies, applying them in new ways to grid operations. In general, smart grid technology can be grouped into five key areas:[5]
- Integrated Communications technologies have the potential to enhance grid communications. Many are already in use but not yet fully integrated. These include: substation automation, advanced meter reading, demand response, distribution automation, supervisory control and data acquisition (SCADA), energy management systems, broadband over power line, wireless technologies, power-line carrier, and fiber-optics. Integrated communications will allow for real-time information and data exchange to optimize system reliability, asset utilization, and security.
- Sensing and Measurement technologies are essential to evaluating equipment health, grid integrity, energy theft prevention, congestion relief, and control strategies support. Technologies include: advanced microprocessor meters (Smart Meters) and meter reading equipment, wide-area monitoring systems, dynamic line rating, electromagnetic signature measurement/analysis, time-of-use and real-time pricing tools, advanced switches and cables, backscatter radio technology, and digital relays.
- Advanced Components are responsible for the electrical behavior of the grid, applying the latest R&D in superconductivity, fault tolerance, storage, power electronics, and diagnostics. Technologies within these broad R&D categories include: flexible alternating current transmission system devices, high voltage direct current, first and second generation superconducting wire, high temperature superconducting cable, distributed energy generation and storage devices, composite conductors, and “intelligent” appliances.
- Advanced Control technologies are devices and algorithms that enable rapid diagnosis of and precise solutions to specific grid disruptions or outages. These technologies rely on and contribute to each of the other four key areas. Three technology categories for advanced control methods are: distributed intelligent agents (control systems), analytical tools (software algorithms and high-speed computers), and operational applications (SCADA, substation automation, demand response, etc.).
- Improved Interfaces and Decision Support provide operators and managers with the tools and training required to operate a smart grid. They convert complex data into easily understood information for decision making. Technologies include visualization techniques that reduce large quantities of data into easily understood visual formats, software systems that provide multiple options when systems operator actions are required, and simulators for operational training and “what-if” analyses.
How Does a Smart Grid Get Built?
editCreating a smart grid will require years as the system evolves through the incremental deployment and integration of “smart” equipment or systems. For example, a utility might change out its conventional electro-mechanical house meters with solid state, two-way communicating meters. These advanced meters will provide enhanced service to customers while providing the utility with new capabilities for operating and maintaining the grid. Installing advanced meters is one step in a utility’s evolution towards a smart grid. But before a utility installs an advanced metering system, or any type of smart system, it must make a business case for the investment. Most utilities find it difficult to justify installing a communications infrastructure for a single application (e.g. meter reading). Because of this, a utility typically must identify several applications that will use the same communications infrastructure – for example, reading a meter, monitoring power quality, remote connection and disconnection of customers, enabling demand response, etc. Ideally, the communications infrastructure will not only support near-term applications, but unanticipated applications that will arise in the future. Regulatory or legislative actions can also drive utilities to implement pieces of a smart grid puzzle. Each utility has a unique set of business, regulatory, and legislative drivers that guide its investments. This means that each utility will take a different path in creating its smart grid and that different utilities will create smart grids at different rates.
R&D Programs
editIntelliGrid – Created by the Electric Power Research Institute (EPRI), IntelliGrid is a vision of the future electric delivery system. The IntelliGrid Consortium is a public/private partnership that integrates and optimizes global research efforts, funds technology R&D, works to integrate technologies, and disseminates technical information.[6] IntelliGrid architecture provides methodology, tools, and recommendations for standards and technologies for utility use in planning, specifying, and procuring IT-based systems, such as advanced metering, distribution automation, and demand response. The architecture also provides a living laboratory for assessing devices, systems, and technology. Several utilities have applied IntelliGrid architecture including Southern California Edison, Long Island Power Authority, Salt River Project, and TXU Electric Delivery.
Modern Grid Initiative (MGI) is a collaborative effort between the U.S. Department of Energy (DOE), the National Energy Technology Laboratory(NETL), utilities, consumers, researchers, and other grid stakeholders to develop a common, national vision to modernize the U.S. electrical grid. MGI supports demonstrations of key systems and technologies that serve as the foundation for an integrated, modern power grid. DOE’s Office of Electricity Delivery and Energy Reliability (OE) sponsors the initiative, which builds upon Grid 2030 and the National Electricity Delivery Technologies Roadmap and is aligned with other programs such as GridWise and GridWorks.[7]
Grid 2030 – Grid 2030 is a joint vision statement for the U.S. electrical system developed by the electric utility industry, equipment manufacturers, information technology providers, federal and state government agencies, interest groups, universities, and national laboratories. It covers generation, transmission, distribution, storage, and end-use.[8] The National Electric Delivery Technologies Roadmap is the implementation document for the Grid 2030 vision. The Roadmap outlines the key issues and challenges for modernizing the grid and suggests paths that government and industry can take to build America’s future electric delivery system.[9]
GridWise – A DOE OE program focused on developing information technology to modernize the U.S. electrical grid. Working with the GridWise Alliance,the program invests in communications architecture and standards; simulation and analysis tools; smart technologies; test beds and demonstration projects; and new regulatory, institutional, and market frameworks. The GridWise Alliance is a consortium of public and private electricity sector stakeholders, providing a forum for idea exchanges, cooperative efforts, and meetings with policy makers at federal and state levels.[10]
GridWorks – A DOE OE program focused on improving the reliability of the electric system through modernizing key grid components such as cables and conductors, substations and protective systems, and power electronics. The program’s focus includes coordinating efforts on high temperature superconducting systems, transmission reliability technologies, electric distribution technologies, energy storage devices, and GridWise systems.[11]
Footnotes
edit- ^ Energy Future Coalition, “Challenge and Opportunity: Charting a New Energy Future,” Appendix A: Working Group Reports, Report of the Smart Grid Working Group. http://www.energyfuturecoalition.org/pubs/app_smart_grid.pdf
- ^ Energy Future Coalition, “Challenge and Opportunity: Charting a New Energy Future,” Appendix A: Working Group Reports, Report of the Smart Grid Working Group. http://www.energyfuturecoalition.org/pubs/app_smart_grid.pdf
- ^ Mazza, Patrick, “The Smart Energy Network: Electricity’s Third Great Revolution,” c. 2003. http://climatesolutions.org/pubs/pdfs/SmartEnergy.pdf
- ^ Global Environment Fund, Center for Smart Energy, “The Emerging Smart Grid: Investment and Entrepreneurial Potential in the Electric Power Grid of the Future,” October 2005. http://www.globalenvironmentfund.com/GEF%20white%20paper_Electric%20Power%20Grid.pdf
- ^ U.S. Department of Energy, National Energy Technology Laboratory, Modern Grid Initiative, http://www.netl.doe.gov/moderngrid/opportunity/vision_technologies.html
- ^ Electric Power Research Institute, IntelliGrid Program, http://www.epri.com/IntelliGrid/default.asp.
- ^ U.S. Department of Energy, National Energy Technology Laboratory, http://www.netl.doe.gov/moderngrid
- ^ U.S. Department of Energy, Office of Electric Transmission and Distribution, “Grid 2030” A National Vision for Electricity’s Second 100 Years, July 2003, http://www.oe.energy.gov/DocumentsandMedia/Elec_Vision_2-9-4.pdf.
- ^ U.S. Department of Energy, Office of Electric Transmission and Distribution, “National Electric Delivery Technologies Roadmap,” http://www.oe.energy.gov/DocumentsandMedia/ER_2-9-4.pdf.
- ^ U.S. Department of Energy, Office of Electricity Delivery and Energy Reliability, http://www.electricdistribution.ctc.com/index.htm; GridWise Program fact sheet, http://www.electricdistribution.ctc.com/pdfs/GridWise%20Fact%20Sheet%20Jan05.pdf; and GridWise Alliance, http://www.gridwise.org.
- ^ U.S. Department of Energy, Office of Electricity Delivery and Energy Reliability, http://www.oe.energy.gov/randd/gridworks.htm