Tuesday, November 9, 2010

What a Smart Grid is

There is a difference between "What is a Smart Grid" and "What a Smart Grid is".

The function of an Electrical grid is not a single entity but an aggregate of multiple networks and multiple power generation companies with multiple operators employing varying levels of communication and coordination, most of which is manually controlled. Smart grids increase the connectivity, automation and coordination between these suppliers, consumers and networks that perform either long distance transmission or local distribution tasks.



  • Transmission networks move electricity in bulk over medium to long distances, are actively managed, and generally operate from 345kV to 800kV over AC and DC lines.

  • Local networks traditionally moved power in one direction, "distributing" the bulk power to consumers and businesses via lines operating at 132kV and lower.

This paradigm is changing as businesses and homes begin generating more wind and solar electricity, enabling them to sell surplus energy back to their utilities. Modernization is necessary for energy consumption efficiency, real time management of power flows and to provide the bi-directional metering needed to compensate local producers of power. Although transmission networks are already controlled in real time, many in the US and European countries are antiquated[13] by world standards, and unable to handle modern challenges such as those posed by the intermittent nature of alternative electricity generation, or continental scale bulk energy transmission.


Modernizes both transmission and distribution


A smart grid is an umbrella term that covers modernization of both the transmission and distribution grids. The modernization is directed at a disparate set of goals including facilitating greater competition between providers, enabling greater use of variable energy sources, establishing the automation and monitoring capabilities needed for bulk transmission at cross continent distances, and enabling the use of market forces to drive energy conservation.


Many smart grid features readily apparent to consumers such as smart meters serve the energy efficiency goal. The approach is to make it possible for energy suppliers to charge variable electric rates so that charges would reflect the large differences in cost of generating electricity during peak or off peak periods. Such capabilities allow load control switches to control large energy consuming devices such as hot water heaters so that they consume electricity when it is cheaper to produce.


Peak curtailment/levelling and time of use pricing


To reduce demand during the high cost peak usage periods, communications and metering technologies inform smart devices in the home and business when energy demand is high and track how much electricity is used and when it is used. To motivate them to cut back use and perform what is called peak curtailment or peak levelling, prices of electricity are increased during high demand periods, and decreased during low demand periods. It is thought that consumers and businesses will tend to consume less during high demand periods if it is possible for consumers and consumer devices to be aware of the high price premium for using electricity at peak periods, this could mean cooking dinner at 9pm instead of 5pm. When businesses and consumers see a direct economic benefit of not having to pay double for the same energy use to become more energy efficient, the theory is that they will include energy cost of operation into their consumer device and building construction decisions. See Time of day metering and demand response.


According to proponents of smart grid plans,[who?] this will reduce the amount of spinning reserve that electric utilities have to keep on stand-by, as the load curve will level itself through a combination of "invisible hand" free-market capitalism and central control of a large number of devices by power management services that pay consumers a portion of the peak power saved by turning their devices off.


Essential for renewable energy


Supporters of renewable energy favor smarter grids, because most renewable energy sources are intermittent in nature, depending on natural phenomena (the sun and the wind) to generate power. Thus, any type of power infrastructure using a significant portion of intermittent renewable energy resources must have means of effectively reducing electrical demand by "load shedding" in the event that the natural phenomena necessary to generate power do not occur. By increasing electricity prices exactly when the desired natural phenomena are not present, consumers will, in theory, decrease consumption. However this means prices are unpredictable and literally vary with the weather, at least to the distribution utility.


Platform for advanced services


As with other industries, use of robust two-way communications, advanced sensors, and distributed computing technology will improve the efficiency, reliability and safety of power delivery and use. It also opens up the potential for entirely new services or improvements on existing ones, such as fire monitoring and alarms that can shut off power, make phone calls to emergency services and etc..


US and UK savings estimates and assumptions behind them


One United States Department of Energy study calculated that internal modernization of US grids with smart grid capabilities would save between 46 and 117 billion dollars over the next 20 years[14]. As well as these industrial modernization benefits, smart grid features could expand energy efficiency beyond the grid into the home by coordinating low priority home devices such as water heaters so that their use of power takes advantage of the most desirable energy sources. Smart grids can also coordinate the production of power from large numbers of small power producers such as owners of rooftop solar panels — an arrangement that would otherwise prove problematic for power systems operators at local utilities.


The above vision makes two assumptions. First, that they will act in response to market signals and there needs to be some sort of telecommunications network. In the UK, where consumers have for nearly 10 years had a choice in the company from which they purchase electricity, more than 80% have stayed with their existing supplier, despite the fact that there are significant differences in the prices offered by a given electricity supplier. End users may be less responsive to price signals than proponents of Smart Grids think. Second, in the case of the telecomms aspect of Smart Grids, this ignores the possibility of bringing autonomy to a given appliance. Various companies (such as RLTec) have developed low cost systems that allow products to react to network fluctuations (usually network frequency). This type of control is called "dynamic demand management". A feature of DDM being that, it is low cost, needs no telecomms network and is available now. Of course these are not points that proponents of a "power telecomms network" may wish to hear about or indeed see propagated.


Although there are specific and proven smart grid technologies in use, smart grid is an aggregate term for a set of related technologies on which a specification is generally agreed, rather than a name for a specific technology. Some of the benefits of such a modernized electricity network include the ability to reduce power consumption at the consumer side during peak hours, called Demand side management; enabling grid connection of distributed generation power (with photovoltaic arrays, small wind turbines, micro hydro, or even combined heat power generators in buildings); incorporating grid energy storage for distributed generation load balancing; and eliminating or containing failures such as widespread power grid cascading failures. The increased efficiency and reliability of the smart grid is expected to save consumers money and help reduce CO2 emissions.


History


Today's alternating current power grid evolved after 1896, based in part on Nikola Tesla's design published in 1888 (see War of Currents). Many implementation decisions that are still in use today were made for the first time using the limited emerging technology available 120 years ago. Specific obsolete power grid assumptions and features (like centralized unidirectional[1] electric power transmission, electricity distribution, and demand-driven control) represent a vision of what was thought possible in the 19th century.


Part of this is due to an institutional risk aversion that utilities naturally feel regarding use of untested technologies on a critical infrastructure they have been charged with defending against any failure, however momentary.[citation needed]


Over the past 50 years, electricity networks have not kept pace with modern challenges, such as:



  • security threats, from either energy suppliers or cyber attack

  • national goals to employ alternative power generation sources whose intermittent supply makes maintaining stable power significantly more complex

  • conservation goals that seek to lessen peak demand surges during the day so that less energy is wasted in order to ensure adequate reserves

  • high demand for an electricity supply that is un-interruptible

  • digitally controlled devices that can alter the nature of the electrical load (giving the electric company the ability to turn off appliances in your home if they see fit) and result in electricity demand that is incompatible with a power system that was built to serve an “analog economy.” For a simple example, timed Christmas lights can present significant surges in demand because they come on at near the same time (sundown or a set time).[citation needed] Without the kind of coordination that a smart grid can provide, the increased use of such devices lead to electric service reliability problems, power quality disturbances, blackouts, and brownouts [15].

Although these points tend to be the "conventional wisdom" with respect to smart grids, their relative importance is debatable. For instance, despite the weaknesses of power network being publicly broadcast, there has never been an attack on a power network in the United States or Europe.[citation needed] However, in April 2009 it was learned that spies had infiltrated the power grids, perhaps as a means to attack the grid at a later time.[citation needed] In the case of renewable power and its variability, recent work undertaken in Europe (Dr. Bart Ummels et al.)[Full citation needed] suggests that a given power network can take up to 30% renewables (such as wind and solar) without any changes whatsoever.


The term smart grid has been in use since at least 2005, when the article "Toward A Smart Grid", authored by S. Massoud Amin and Bruce F. Wollenberg appeared in the September/October issue of IEEE P&E Magazine (Vol. 3, No.3, pgs 34-41). The term had been used previously and may date as far back as 1998. There are a great many smart grid definitions, some functional, some technological, and some benefits-oriented. A common element to most definitions is the application of digital processing and communications to the power grid, making data flow and information management central to the smart grid. Various capabilities result from the deeply integrated use of digital technology with power grids, and integration of the new grid information flows into utility processes and systems is one of the key issues in the design of smart grids. Electric utilities now find themselves making three classes of transformations: improvement of infrastructure, called the strong grid in China; addition of the digital layer that is the essence of the smart grid; and business process transformation, necessary to capitalize on the investments in smart technology. Much of the modernization work that has been going on in electric grid modernization, especially substation and distribution automation, is now included in the general concept of the smart grid, but additional capabilities are evolving as well.


Smart grid technologies have emerged from earlier attempts at using electronic control, metering, and monitoring. In the 1980s, Automatic meter reading was used for monitoring loads from large customers, and evolved into the Advanced Metering Infrastructure of the 1990s, whose meters could store how electricity was used at different times of the day.[16] Smart meters add continuous communications so that monitoring can be done in real time, and can be used as a gateway to demand response-aware devices and "smart sockets" in the home. Early forms of such Demand side management technologies were dynamic demand aware devices that passively sensed the load on the grid by monitoring changes in the power supply frequency. Devices such as industrial and domestic air conditioners, refrigerators and heaters adjusted their duty cycle to avoid activation during times the grid was suffering a peak condition. Beginning in 2000, Italy's Telegestore Project was the first to network large numbers (27 million) of homes using such smart meters connected via low bandwidth power line communication[17]. Recent projects use Broadband over Power Line (BPL) communications, or wireless technologies such as mesh networking that is advocated as providing more reliable connections to disparate devices in the home as well as supporting metering of other utilities such as gas and water[citation needed].


Monitoring and synchronization of wide area networks were revolutionized the early 1990s when the Bonneville Power Administration expanded its smart grid research with prototype sensors that are capable of very rapid analysis of anomalies in electricity quality over very large geographic areas. The culmination of this work was the first operational Wide Area Measurement System (WAMS) in 2000[18]. Other countries are rapidly integrating this technology — China will have a comprehensive national WAMS system when its current 5-year economic plan is complete in 2012[19].


First cities with smart grids


The earliest, and still largest, example of a smart grid is the Italian system installed by Enel S.p.A. of Italy. Completed in 2005, the Telegestore project was highly unusual in the utility world because the company designed and manufactured their own meters, acted as their own system integrator, and developed their own system software. The Telegestore project is widely regarded as the first commercial scale use of smart grid technology to the home, and delivers annual savings of 500 million € at a project cost of 2.1 billion €.[17].


In the US, the city of Austin, Texas has been working on building its smart grid since 2003, when its utility first replaced 1/3 of its manual meters with smart meters that communicate via a wireless mesh network. It currently manages 200,000 devices real-time (smart meters, smart thermostats, and sensors across its service area), and expects to be supporting 500,000 devices real-time in 2009 servicing 1 million consumers and 43,000 businesses[20]. Boulder, Colorado completed the first phase of its smart grid project in August 2008. Both systems use the smart meter as a gateway to the home automation network (HAN) that controls smart sockets and devices. Some HAN designers favor decoupling control functions from the meter, out of concern of future mismatches with new standards and technologies available from the fast moving business segment of home electronic devices[21].


Hydro One, in Ontario, Canada is in the midst of a large-scale Smart Grid initiative, deploying a standards-compliant communications infrastructure from Trilliant. By the end of 2010, the system will serve 1.3 million customers in the province of Ontario. The initiative won the "Best AMR Initiative in North America" award from the Utility Planning Network. [22]


Problem definition


The major driving forces to modernize current power grids can be divided in four, general categories.



  • Increasing reliability, efficiency and safety of the power grid.

  • Enabling decentralized power generation so homes can be both an energy client and supplier (provide consumers with interactive tool to manage energy usage).

  • Flexibility of power consumption at the clients side to allow supplier selection (enables distributed generation, solar, wind, biomass).

  • Increase GDP by creating more new, green-collar energy jobs related to renewable energy industry manufacturing, plug-in electric vehicles, solar panel and wind turbine generation, energy conservation construction[23][24].

The following footnotes and links will be published with each blog in this series.


Footnotes

  1. http://earth2tech.com/2009/06/05/why-the-smart-grid-wont-have-the-innovations-of-the-internet-any-time-soon/
  2. http://earth2tech.com/2009/04/21/ciscos-latest-consumer-play-the-smart-grid/
  3. http://earth2tech.com/2008/05/01/silver-springs-the-cisco-of-smart-grid/
  4. http://earth2tech.com/2009/05/20/utility-perspective-why-partner-with-google-powermeter/
  5. http://www.ecommercetimes.com/story/67126.html?wlc=1245096400&wlc=1245366756
  6. Supersmart grid paper
  7. http://earth2tech.com/2009/04/20/smart-grid-miami-fpl-ge-cisco-silver-spring-rolling-out-1m-smart-meters/
  8. "The rise of the Smart Grid". Deloitte TMT Predictions. http://www.deloitte.co.uk/TMTPredictions/technology/SmartGrid-electricity-grid-efficiency.cfm.
  9. "Obama's Speech on the Economy". New York Times. 2009-01-09. http://www.nytimes.com/2009/01/08/us/politics/08text-obama.html?pagewanted=4.
  10. "NIST Announces Three Phase Plan for Smart Grid". National Institute for Standards and Technology. 2009-04-13. http://www.nist.gov/public_affairs/smartgrid_041309.html.
  11. NIST announces smart grid interoperability project via IEEE P2030, June 2009
  12. St. Arnaud's "green broadband" news
  13. The Federal Energy Regulatory Commission Chairman Pat Wood, III (appointed by George Bush) stated that the US transmission system cannot afford to be "antiquated" in this news release Federal Energy Regulatory Commission (2002-09-18) (pdf). FERC news release on ISO. p. 1. http://www.ferc.gov/news/news-releases/2002/2002-3/Sept18rto9.pdf. Retrieved 2009-04-29.
  14. [L. D. Kannberg]; M. C. Kintner-Meyer, D. P. Chassin, R. G. Pratt, J. G. DeSteese, L. A. Schienbein, S. G. Hauser, W. M. Warwick (2003-11) (pdf). GridWise: The Benefits of a Transformed Energy System. Pacific Northwest National Laboratory under contract with the United States Department of Energy. p. 25. http://arxiv.org/pdf/nlin/0409035. Retrieved 2008-12-05.
  15. Smart Grid Working Group (2003-06) (pdf). Challenge and Opportunity: Charting a New Energy Future, Appendix A: Working Group Reports. Energy Future Coalition. http://www.energyfuturecoalition.org/files/webfmuploads/EFC_Report/EFCReport.pdf. Retrieved 2008-11-27.
  16. Federal Energy Regulatory Commission staff report (2006-08) (pdf). Assessment of Demand Response and Advanced Metering (Docket AD06-2-000). United States Department of Energy. p. 20. http://www.ferc.gov/legal/staff-reports/demand-response.pdf. Retrieved 2008-11-27.
  17. a b National Energy Technology Laboratory (2007-08) (pdf). NETL Modern Grid Initiative — Powering Our 21st-Century Economy. United States Department of Energy Office of Electricity Delivery and Energy Reliability. p. 17. http://www.netl.doe.gov/moderngrid/docs/Modern%20Grid%20Benefits_Final_v1_0.pdf. Retrieved 2008-12-06.
  18. "Gridwise History: How did GridWise start?". Pacific Northwest National Laboratory. 2007-10-30. http://gridwise.pnl.gov/foundations/history.stm. Retrieved 2008-12-03.
  19. a b c d Qixun Yang, Board Chairman, Beijing Sifang Automation Co. Ltd., China and .Bi Tianshu, Professor, North China Electric Power University, China. (2001-06-24). "WAMS Implementation in China and the Challenges for Bulk Power System Protection" (pdf). Panel Session: Developments in Power Generation and Transmission — Infrastructures in China, IEEE 2007 General Meeting, Tampa, FL, USA, 24–28 June 2007 Electric Power, ABB Power T&D Company, and Tennessee Valley Authority (Institute of Electrical and Electronics Engineers). http://www.ewh.ieee.org/cmte/ips/2007GM/2007GM_china_intro.pdf. Retrieved 2008-12-01.
  20. "Building for the future: Interview with Andres Carvallo, CIO — Austin Energy Utility". Next Generation Power and Energy (GDS Publishing Ltd.) (244). http://nextgenpe.com/currentissue/article.asp?art=273073&issue=244. Retrieved 2008-11-
  21. Betsy Loeff (2008-03). "AMI Anatomy: Core Technologies in Advanced Metering". Ultrimetrics Newsletter (Automatic Meter Reading Association (Utilimetrics)). http://www.utilimetrics.org/newsletter/index.cfm?fuseaction=Newsletter.showIssuetoPrint&Issue_ID=68. Retrieved 2008-11-26.
  22. Demanding standards: Hydro One aims to leverage AMI via interoperability
  23. Smartgrids Advisory Council. "Driving Factors in the Move Towards Smartgrids" (PDF). European Smartgrids Technology Platform: Vision and Strategy. European Commission. p. 9. ISBN 92-79-01414-5. http://www.smartgrids.eu/documents/vision.pdf.
  24. a b National Energy Technology Laboratory (2007-07-27) (pdf). A Vision for the Modern Grid. United States Department of Energy. p. 5. http://www.netl.doe.gov/moderngrid/docs/A%20Vision%20for%20the%20Modern%20Grid_Final_v1_0.pdf. Retrieved 2008-11-27.
  25. Anderson, Roger; A. Boulanger, J. A. Johnson and A. Kressner (2008 ISBN 978-1-59370-157-4). p 333. Computer-Aided Lean Management for the Energy Industry.
  26. 2007 IBM Energy and Utilities Global Residential/Small Business Consumer Survey http://www-03.ibm.com/industries/utilities/doc/content/landingdtw/3165578119.html?g_type=pspot
  27. page 10
  28. 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
  29. U.S. Department of Energy, National Energy Technology Laboratory, Modern Grid Initiative, http://www.netl.doe.gov/moderngrid/opportunity/vision_technologies.html
  30. Yilu Liu, Lamine Mili, Jaime De La Ree, Reynaldo Francisco Nuqui, Reynaldo Francisco Nuqui (2001-07-12). "State Estimation and Voltage Security Monitoring Using Synchronized Phasor Measurement" (pdf). Research paper from work sponsored by American Electric Power, ABB Power T&D Company, and Tennessee Valley Authority (Virginia Polytechnic Institute and State University). http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=3B975B94733D906CA197813C53C2BD86?doi=10.1.1.2.7959&rep=rep1&type=pdf. Retrieved 2008-12-01. abstract Lay summary. ""Simulations and field experiences suggest that PMUs can revolutionize the way power systems are monitored and controlled."".
  31. a b Patrick Mazza (2005-04-27) (doc). [http://fortress.wa.gov/wutc/home/webdocs.nsf/de53b07997d108ea882563b50072c5b3/bc3ced6bb5f4cf29882570200083aaa3/$FILE/Powering%20Up%20Smart%20Grid%20report.doc Powering Up the Smart Grid: A Northwest Initiative for Job Creation, Energy Security, and Clean, Affordable Electricity.]. Climate Solutions. p. 7. http://fortress.wa.gov/wutc/home/webdocs.nsf/de53b07997d108ea882563b50072c5b3/bc3ced6bb5f4cf29882570200083aaa3/$FILE/Powering%20Up%20Smart%20Grid%20report.doc. Retrieved 2008-12-01.
  32. (pdf) Wide Area Protection System for Stability. Nanjing Nari-Relays Electric Co., Ltd. 2008-04-22. p. 2. http://www.nari-relays.com/en/files/Wide%20Area%20Protection%20System%20for%20Stability.pdf. Retrieved 2008-12-12. Examples are given of two events, one stabilizing the system after a fault on a 1 gigawatt HVDC feed, with response timed in milliseconds.
  33. "On-Line Voltage Stability Monitoring and Control (VSMC) System in Fujian power grid" (pdf). Proceedings, Power Engineering Society General Meeting, 2007. (Tampa, FL, USA: IEEE). 2007-06-24. doi:10.1109/PES.2007.385975. Lay summary.
  34. Cisco Outlines Strategy for Highly Secure, 'Smart Grid' Infrastructure
  35. Why the Smart Grid must be based on IP standards
  36. IEEE P2030 Official Website
  37. EETimes.com: IEEE, conference drive smart grids - P2030 aims to develop a guide to grid standards
  38. Commerce Secretary Unveils Plan for Smart Grid Interoperability
  39. Li, Jerry (2009), From Strong to Smart: the Chinese Smart Grid and its relation with the Globe, AEPN, Article No. 0018602, Asia Energy Platform. Available at http://www.aepfm.org/link.php
  40. http://www.smartgrids.eu/: Look under 'background'
  41. "U.S. Energy Independence and Security Act of 2007". http://www.thomas.gov/cgi-bin/query/z?c110:H.R.6.ENR:. Retrieved 2007-12-23.
  42. http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=110_cong_public_laws&docid=f:publ140.110
  43. http://apps1.eere.energy.gov/news/news_detail.cfm/news_id=12364
  44. "Report: Smart Grid Market Could Double in Four Years". Zpryme Smart Grid Market. http://www.smartgridnews.com/artman/publish/Business_Markets_Pricing_News/Report-Smart-Grid-Market-Could-Double-in-Four-Years-1662.html.
  45. http://www.e-energy.de/en/index.php
  46. a b c d e Massachusetts rejects utility's prepayment plan for low income customers, The Boston Globe, 2009-07-23

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