Transmission Line Loss - Report


Published on is a leader in GIS technology solutions for line loss issues.

Published in: Technology, Business
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Transmission Line Loss - Report

  1. 1. Line-LossLine-Loss is a constant battle for electric utility companies regardless of their size. Whatonce was an acceptable level for line-losses can no longer be acceptable. According tothe Department of Energy1, it is estimated that United States utilities lost 6.6% in 1997and of 6.5% in 2007. In some cases the percentage of line-loss reaches 10% - 15%. Thiscan result in multi-million dollar losses.In a letter to U.S. Department of Energy Secretary Spencer Abraham, National RuralElectric Cooperative Association (NRECA) Chief Executive Officer Glen English had this tosay about distribution system line losses: Resistance to the flow of electrical current in the distribution and transmission system causes a portion of energy, typically 7 percent, to be lost in the form of heat, resulting in higher emissions for the same amount of delivered electricity. Data from the USDA’s Rural Utilities Service (RUS) show that cooperative distribution system line losses were consistently around 6% from 1994 to 2000, well below the industry norm. In fact, RUS reported cooperative line losses at 4.96% during 2001. While electric cooperatives serve 12% of all electric consumers, they maintain nearly half (2.3 million miles) of the nation’s distribution miles of line. With their consumers widely dispersed (6.6 consumers per mile compared to 34 for investor-owned utilities and 44 for municipals), cooperatives have maintained a high degree of distribution efficiency under very challenging conditions. 2The U.S. Energy Information Administration (eia) has created a table of the “StateElectricity Profiles”. The total for the United States is as follows: Average Retail Net Summer Total Retail Net Generation Name Price Capacity Sales (cents/kWh) (megawatts) (megawatthours) (megawatthours) U.S. 9.82 1,025,400 3,950,330,926 3,596,864,866 TotalSource: U.S. Energy Information Administration website, Date of Data: 2009, Published: April 2011.CausesThere are numerous issues4 that cause line-loss for utilities including: • Inaccuracy of wholesale metering CT’s & PT’s • No-load losses within the electric system • Inaccuracy of revenue Meters (calibrations, multipliers, defective, age, sizing, etc.)
  2. 2. • Energy Thefts • Un-Metered Errors, especially street and security lights • Billing System account set-up errors • Poor power factor • Phase imbalance • Improper primary/secondary conductor size.Federal InvolvementThe federal government began the process of mandating Smart Grid technology withthe Bush Administration. The Obama Administration has not missed a beat in their pushfor Smart Grid technology. On June 13, 2011 the Obama Administration released thispress release “Administration Announces Grid Modernization Initiatives to Foster aClean Energy Economy and Spur Innovation”5. There are 4 primary goals mentioned inthis press release: 1. Better alignment of economic incentives to boost development and deployment of smart-grid technologies 2. A greater focus on standards and interoperability to enable greater innovation 3. Empowerment of consumers with enhanced information to save energy, ensure privacy, and shrink bills 4. Improved grid security and resilienceIn an effort to meet these goals the Obama Administration released these public andprivate-sector initiatives: • $250 million in loans for smart-grid technology deployment as part of the US Department of Agriculture’s Rural Utility Service, which is focused on upgrading the electric grid in rural America. • The launch of Grid 21, a private sector initiative to promote consumer-friendly innovations while ensuring proper privacy safeguards and consumer protections. Grid 21 will help consumers get better access to their own energy usage information so that they can take advantage of new tools and services to manage their energy use and save on their utility bills. • New commitments by the Department of Energy to focus on improving consumer access to their own energy information, including the development of a crowd-sourced map to track progress, a data-driven competition designed to harness the imagination and enthusiasm of America’s students to encourage home energy efficiency, and new EIA efforts to measure progress. o Consumers deserve access to their own energy usage information in consumer-friendly and computer-friendly formats. The Administration is
  3. 3. committed to working with States and stakeholders to ensure all Americans can take advantage of new tools and services to manage their energy use and save on their utility bills. With proper privacy safeguards and consumer protections, a smarter electricity system can benefit all consumers. • Expanded partnerships to continue working with States and stakeholders, including an initiative to share lessons learned from Recovery Act smart grid investments, a series of regional peer-to-peer stakeholder meetings, and updated online resources available at: • The formation of a Renewable Energy Rapid Response Team, co-led by the White House Council on Environmental Quality, the Department of the Interior, and the Department of Energy, to improve Federal coordination and ensure timely review of proposed renewable energy projects and transmission lines, to ensure that renewable energy can power cities and towns across America, and to increase reliability and save consumers money by modernizing the grid.These initiatives are the focus of the American Recovery and Reinvestment Act of 20096allocation to Smart Grid issues. The Green Energy initiatives involving Wind and Solarpower will play a role in replacing the fossil fuel generation of the past as we moveforward in upgrading our transmission grid in the United States.Upgrading the transmission grid is a necessary element that should have been started along time ago. If the transmission is not upgraded then maximum results cannot beachieved by the smart grid. Possible solutions7 for transmission are High-Voltage DirectCurrent (HVDC), Flexible AC Transmission Systems (FACTS) devices, Gas-InsulatedSubstations, Superconductors, Wide Area Monitoring Systems (WAMS), etc.ABB7 wrote a white paper on these solutions listed above. HVDC has 25% lower line-losses compared to the traditional AC transmission lines while having up to 5 times thecapacity of AC lines. The superconductors called HTS (high temperaturesuperconducting) carry a line loss of .5% compared to the 5-8% of the traditionalconductors.Distribution SolutionsABB also listed other paths to improved efficiency. Here are those proposed paths: • Distributed generation/Microgrids • Underground distribution lines • Intelligent grid design (smart grids via automation) • Reduction of overall T&D transformer MVA • Energy storage devices • Three phase design for distribution
  4. 4. • Ground wire loss reduction techniques • Higher transmission operating voltages • Voltage optimization through reactive power compensation • Asset replacement schedule optimization • Distribution loss reduction via distribution automation • Power factor improvement • Load management (e.g., smart metering or price-sensitive load control) • Power electronic transformersAMR/AMI systems have been the first to attack the line-loss issue facing the electricutilities. Those utilities who deployed AMR/AMI systems like Aclara’s TWACS metering,have seen an increase in revenues due to more accurate meter billing. Solving theseissues first will result in the highest Return on Investment.As the Smart Grid matures, more devices will be brought into the fold for monitoring.Transformers are next on the list and are beginning to be tested. They should be readyin the next 5 years for manufacturing and deployment to utilities. Soon to follow areother protective devices with monitoring systems for the distribution conductors.Data Generated by the Smart GridNow we have the question, how is the data gathered and organized. GeographicInformation Systems (GIS) becomes an essential tool for the organization and analysis ofdata. Without a GIS in place the analysis of data, creation of reports, and gathering ofdata becomes difficult. It is important that the data from the different sources isinteroperable with each other. The best way to ensure this interoperability is to requirethat vendors providing the Smart Grid components be MultiSpeak( compliant. If you have not heard of the MultiSpeak standard hereis a description from MultiSpeak’s “About” page8: The MultiSpeak Specification is a key industry-wide standard for realizing the potential of enterprise application interoperability. The MultiSpeak Specification is the most widely applied de facto standard in North America pertaining to distribution utilities and all portions of vertically- integrated utilities except generation and power marketing. It is currently in use in daily operations of more than 600 electric cooperatives, investor- owned utilities, municipals, and public power districts in at least 15 different countries. The MultiSpeak Initiative is a collaboration of the National Rural Electric Cooperative Association (NRECA), leading software vendors supplying the utility market, and utilities. The Initiative has developed and continues to expand the MultiSpeak Specification for Interoperability a specification
  5. 5. that defines standardized interfaces among enterprise software applications commonly used by electric utilities.GIS is the foundation of the organization of data. From this foundation the utility canefficiently perform engineering analysis, outage management (which we will discuss inthe next chapter), improve customer service, provide pay via phone or online usingcredit/debit cards, integrate automated vehicle location (AVL), laptops with distributionsystem, etc. All of these activities create more efficiency in the utility. Utilities areconstantly being bombarded with accusations of rising utility rates from theircustomers. With the reduction of line-loss those rates could come down. In order toreduce line-loss efficiently the data must be organized, presented and analyzed in such away that issues on the distribution system are solved in a systematic approach. GISallows this systematic approach to be developed and shows trends and patternsgraphically. If there is no GIS then some patterns/trends could or would be missed.As we move forward with the Smart Grid, the installation and use of GIS is becoming anessential tool that utilities cannot live without. The utilities that see this vision beforeinvesting in Smart Grid upgrades that are not interoperable, will have saved not onlymoney but aggravation as well.