NERC Tag
Encyclopedia
A NERC Tag, also commonly referred to as an E-Tag, represents a transaction on the North America
n bulk electricity market scheduled to flow within, between or across electric utility company territories. The NERC Tag is named for the North American Electric Reliability Corporation (NERC), which is the entity that was responsible for the implementation of the first energy tagging processes. NERC Tags were first introduced in 1997, in response to the need to track the increasingly complicated energy transactions
which were produced as a result of the beginning of electric deregulation
in North America.
's Energy Policy Act of 1992
was the first major step towards electric deregulation in North America, and was followed by a much more definitive action when FERC issued Orders 888 and 889 in 1996, which laid the groundwork for formalized deregulation of the industry and led to the creation of the network of Open Access Same-Time Information System (OASIS)
nodes.
FERC is an independent agency
of the U.S. Government
and thus its authority extends only over electric utilities
operating in the United States. However, NERC members include all of the FERC footprint as well as all of the electric utilities in lower Canada
and a Mexican
utility company. In the interest of reciprocity and commonality, all NERC members generally cooperate with FERC rules.
The creation of OASIS nodes allowed for energy to be scheduled across multiple power systems, creating complex strings of single "point-to-point" transactions which could be connected end-to-end to literally travel across the continent. This frequently created situations where it was difficult or impossible for transmission system operator
s to ascertain all of the transactions impacting their local system or take any corrective actions to alleviate situations which could put the power grid
at risk of damage or collapse. The NERC Tag was implemented as a result of this new problem introduced by deregulation.
spreadsheet
, and was introduced in 1997. The form was usually completed by the power marketers or schedulers, by defining the date and time of the transaction, the physical path of the energy schedule from its point of generation
to point of consumption, the financial path (buying/selling chain) of the energy schedule, the hourly energy amounts scheduled to flow, and also the OASIS transmission requests for each power system crossed which thereby documented that permission to cross each power system had been properly obtained.
Elements of a NERC Tag included Control Areas (CA), Transmission Providers (TP), Purchasing/Selling Entities (PSE), transmission Points of Receipt (POR) and Points of Delivery (POD), as well as product codes for several transmission and generation priorities.
The physical path was the most important aspect of the NERC Tag in terms of understanding the impact of a collection of individual transactions after they had been compiled into a single complete transaction. To complete the physical path it was necessary to identify the power system and power plant where the energy was to be generated, any and all power systems that would be utilized to move the energy to its eventual destination, and lastly the power system and location of the delivery point where the energy would be consumed (the "load").
When a NERC Tag was created in the spreadsheet, the information was then distilled into a small CSV
formatted data packet which was disseminated via e-mail
to all of the participants listed on the NERC tag. In this way, all participants of a transaction were able to determine which other electric utilities and power marketers were involved in the transaction, and what the roles of the other participants were. More importantly, in the event of a contingency such as a transmission line outage
or generation failure, all participants could more easily be notified of the schedule change, and could then all act in cooperation to curtail the scheduled transaction.
The NERC Tag 1.0 implementation was not capable of collecting schedule flow data in any useful way, but it did serve to familiarize schedulers with the demands of tagging their transactions, a process that would eventually be mandatory. A database of transmission scheduling points maintained by NERC through the Transmission System Information Networks (TSIN) that was originally developed for the OASIS nodes was greatly expanded to include additional information required in the process of creating NERC Tags.
The spreadsheet-based NERC Tag application saw minor improvements in functionality and scope with small incremental changes which advanced it to NERC Tag 1.3, although there was not much discernible difference to the participants, and until version 1.4 was implemented, any previous version could still be used.
connection instead of via e-mail. This eliminated the cumbersome process required to receive a data packet via email and port it back into the original spreadsheet-based tagging application. This change made the NERC Tag much easier to use in a real-time application. E-Tag 1.4 went into effect in 1999, but was replaced just nine months later with E-Tag 1.5, followed three months later with E-Tag 1.501. The 1.5 and 1.501 Specs corrected the shortcomings experienced with the initial release of the first E-Tag Spec.
Although NERC was responsible for the E-Tag Spec, it opened development of the application to run it to the software market. Initially there were numerous E-Tagging software providers, mainly a mix of small start-ups
and new applications developed by existing energy industry software developers. The E-Tag 1.5 Spec was written in such a way that the various applications were permitted to have differing graphical user interfaces (GUIs)
, but functionally "under the hood" they were required to be able to interact with each other when transmitting, receiving and processing E-Tags. A new feature introduced with E-Tag 1.4/1.5, made possible by the real-time sharing of E-Tags, was the ability for reliability entities (namely the CA's and TP's) in the E-Tag to electronically approve or deny E-Tags based on various criteria.
The arrival of real-time tagging also enabled NERC to begin collecting real-time and short-term future data regarding the energy transactions scheduled throughout the North American power grid. The data from approved transactions was ported to the Interchange Distribution Calculator (IDC), where the data could be applied to a virtual study model of the Eastern Interconnection
. The IDC went online in 1999.
Under E-Tag 1.6, NERC implemented the "no tag, no flow" rule, where all energy transactions were to be documented with an E-Tag. Accurate system studies of the Eastern Interconnection in order to determine which schedules should be curtailed would only be possible if every transaction was tagged and therefore included in the IDC calculations. Reliability Coordinators in the Eastern Interconnection could access the IDC online and run flow studies based on various operating scenarios with all of the current energy schedules derived from the E-Tags. When an actual contingency occurred, the Reliability Coordinators could identify the constrained transmission line or corridor within the IDC, and the IDC would then identify which E-Tagged schedules should be curtailed in order to ease the loading on the restricted facilities.
was utilized to format the data transferred between E-Tag applications, finally replacing the base CSV data transfer format based on its ancestral NERC Tag 1.0 spreadsheet/e-mail origins. The TSIN database was expanded to include generation and load points which were matched with PSEs that had rights to schedule them, and also included complex associations that enforced matched sets of PORs and PODs with TPs. E-Tag 1.7 also greatly expanded the time frame flexibility of an E-Tag by allowing extensions and modifications with comprehensive approval processes, layering of multiple OASIS requests for transmission rights, and also fully automated the tag curtailment functions from the IDC so that individual manual tag curtailments were no longer necessary.
Shortly after E-Tag 1.7 went online in 2002, the Western Electricity Coordinating Council (WECC)
implemented the WECC Unscheduled Flow (USF) Tool, which accomplished a similar automated curtailing capability for the Western Interconnection
that the IDC had done for the Eastern Interconnection.
The number of software choices for E-Tag software dwindled within the first few years to a handful of major players. The number of E-Tag users was strictly limited by the number of entities involved in E-Tagging, and the cost of complying with NERC E-Tag Specifications became prohibitive for any software company that did not already have significant market share or adequate financial backing. The added complexities of E-Tag 1.7 dealt a severe blow to most of the E-Tagging software providers, and within a year of E-Tag 1.7 going online, there was only one dominant E-Tag software provider remaining, which also provided all IDC and WECC USF services, though a few holdouts and customer-developed "in-house" E-Tag applications remain.
Version 1.7.097 of E-Tag was implemented on January 3, 2007.
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n bulk electricity market scheduled to flow within, between or across electric utility company territories. The NERC Tag is named for the North American Electric Reliability Corporation (NERC), which is the entity that was responsible for the implementation of the first energy tagging processes. NERC Tags were first introduced in 1997, in response to the need to track the increasingly complicated energy transactions
Electricity market
In economic terms, electricity is a commodity capable of being bought, sold and traded. An electricity market is a system for effecting purchases, through bids to buy; sales, through offers to sell; and short-term trades, generally in the form of financial or obligation swaps. Bids and offers use...
which were produced as a result of the beginning of electric deregulation
Deregulation
Deregulation is the removal or simplification of government rules and regulations that constrain the operation of market forces.Deregulation is the removal or simplification of government rules and regulations that constrain the operation of market forces.Deregulation is the removal or...
in North America.
Electric Deregulation in North America
The Federal Energy Regulatory Commission (FERC)Federal Energy Regulatory Commission
The Federal Energy Regulatory Commission is the United States federal agency with jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, and oil pipeline rates...
's Energy Policy Act of 1992
Energy Policy Act of 1992
The Energy Policy Act is a United States government act.It was passed by Congress and addressed energy efficiency, energy conservation and energy management , natural gas imports and exports , alternative fuels and requiring certain fleets to acquire alternative fuel vehicles, which are capable of...
was the first major step towards electric deregulation in North America, and was followed by a much more definitive action when FERC issued Orders 888 and 889 in 1996, which laid the groundwork for formalized deregulation of the industry and led to the creation of the network of Open Access Same-Time Information System (OASIS)
Open Access Same-Time Information System
The Open Access Same-Time Information System , is an Internet-based system for obtaining services related to electric power transmission in North America. It is the primary means by which high-voltage transmission lines are reserved for moving wholesale quantities of electricity...
nodes.
FERC is an independent agency
Independent agencies of the United States government
Independent agencies of the United States federal government are those agencies that exist outside of the federal executive departments...
of the U.S. Government
Federal government of the United States
The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...
and thus its authority extends only over electric utilities
Electric utility
An electric utility is a company that engages in the generation, transmission, and distribution of electricity for sale generally in a regulated market. The electrical utility industry is a major provider of energy in most countries. It is indispensable to factories, commercial establishments,...
operating in the United States. However, NERC members include all of the FERC footprint as well as all of the electric utilities in lower Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and a Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
utility company. In the interest of reciprocity and commonality, all NERC members generally cooperate with FERC rules.
The creation of OASIS nodes allowed for energy to be scheduled across multiple power systems, creating complex strings of single "point-to-point" transactions which could be connected end-to-end to literally travel across the continent. This frequently created situations where it was difficult or impossible for transmission system operator
Transmission system operator
File:Electricity grid simple- North America.svg|thumb|380px|right|Simplified diagram of AC electricity distribution from generation stations to consumersrect 2 243 235 438 Power stationrect 276 317 412 556 Transformer...
s to ascertain all of the transactions impacting their local system or take any corrective actions to alleviate situations which could put the power grid
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
at risk of damage or collapse. The NERC Tag was implemented as a result of this new problem introduced by deregulation.
NERC Tag 1.x
The earliest NERC Tag application was based on a Microsoft ExcelMicrosoft Excel
Microsoft Excel is a proprietary commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications...
spreadsheet
Spreadsheet
A spreadsheet is a computer application that simulates a paper accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. Each cell contains alphanumeric text, numeric values or formulas...
, and was introduced in 1997. The form was usually completed by the power marketers or schedulers, by defining the date and time of the transaction, the physical path of the energy schedule from its point of generation
Electricity generation
Electricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...
to point of consumption, the financial path (buying/selling chain) of the energy schedule, the hourly energy amounts scheduled to flow, and also the OASIS transmission requests for each power system crossed which thereby documented that permission to cross each power system had been properly obtained.
Elements of a NERC Tag included Control Areas (CA), Transmission Providers (TP), Purchasing/Selling Entities (PSE), transmission Points of Receipt (POR) and Points of Delivery (POD), as well as product codes for several transmission and generation priorities.
The physical path was the most important aspect of the NERC Tag in terms of understanding the impact of a collection of individual transactions after they had been compiled into a single complete transaction. To complete the physical path it was necessary to identify the power system and power plant where the energy was to be generated, any and all power systems that would be utilized to move the energy to its eventual destination, and lastly the power system and location of the delivery point where the energy would be consumed (the "load").
When a NERC Tag was created in the spreadsheet, the information was then distilled into a small CSV
Comma-separated values
A comma-separated values file stores tabular data in plain-text form. As a result, such a file is easily human-readable ....
formatted data packet which was disseminated via e-mail
E-mail
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
to all of the participants listed on the NERC tag. In this way, all participants of a transaction were able to determine which other electric utilities and power marketers were involved in the transaction, and what the roles of the other participants were. More importantly, in the event of a contingency such as a transmission line outage
Power outage
A power outage is a short- or long-term loss of the electric power to an area.There are many causes of power failures in an electricity network...
or generation failure, all participants could more easily be notified of the schedule change, and could then all act in cooperation to curtail the scheduled transaction.
The NERC Tag 1.0 implementation was not capable of collecting schedule flow data in any useful way, but it did serve to familiarize schedulers with the demands of tagging their transactions, a process that would eventually be mandatory. A database of transmission scheduling points maintained by NERC through the Transmission System Information Networks (TSIN) that was originally developed for the OASIS nodes was greatly expanded to include additional information required in the process of creating NERC Tags.
The spreadsheet-based NERC Tag application saw minor improvements in functionality and scope with small incremental changes which advanced it to NERC Tag 1.3, although there was not much discernible difference to the participants, and until version 1.4 was implemented, any previous version could still be used.
E-Tag 1.4 and 1.5
Not long after NERC introduced the NERC Tag spreadsheet and packet emailer, NERC concluded that it did not want involvement in any future software development or maintenance. A NERC Tag specification document, version 1.4, was drafted as the next level in energy tagging, the NERC Tag would subsequently also be known as an E-Tag. Data transfer would now occur directly over an InternetInternet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
connection instead of via e-mail. This eliminated the cumbersome process required to receive a data packet via email and port it back into the original spreadsheet-based tagging application. This change made the NERC Tag much easier to use in a real-time application. E-Tag 1.4 went into effect in 1999, but was replaced just nine months later with E-Tag 1.5, followed three months later with E-Tag 1.501. The 1.5 and 1.501 Specs corrected the shortcomings experienced with the initial release of the first E-Tag Spec.
Although NERC was responsible for the E-Tag Spec, it opened development of the application to run it to the software market. Initially there were numerous E-Tagging software providers, mainly a mix of small start-ups
Startup company
A startup company or startup is a company with a limited operating history. These companies, generally newly created, are in a phase of development and research for markets...
and new applications developed by existing energy industry software developers. The E-Tag 1.5 Spec was written in such a way that the various applications were permitted to have differing graphical user interfaces (GUIs)
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
, but functionally "under the hood" they were required to be able to interact with each other when transmitting, receiving and processing E-Tags. A new feature introduced with E-Tag 1.4/1.5, made possible by the real-time sharing of E-Tags, was the ability for reliability entities (namely the CA's and TP's) in the E-Tag to electronically approve or deny E-Tags based on various criteria.
The arrival of real-time tagging also enabled NERC to begin collecting real-time and short-term future data regarding the energy transactions scheduled throughout the North American power grid. The data from approved transactions was ported to the Interchange Distribution Calculator (IDC), where the data could be applied to a virtual study model of the Eastern Interconnection
Eastern Interconnection
The Eastern Interconnection is one of the two major alternating current power grids in North America. The other major interconnection is the Western Interconnection...
. The IDC went online in 1999.
E-Tag 1.6
Building on the lessons experienced with E-Tag applications to date, E-Tag 1.6 went into effect in 2000. There were seven variations of E-Tag 1.6, up to E-Tag 1.67 which was in effect until late 2002. Most of the changes in E-Tag 1.6 were of a functional nature and not overly apparent to the users.Under E-Tag 1.6, NERC implemented the "no tag, no flow" rule, where all energy transactions were to be documented with an E-Tag. Accurate system studies of the Eastern Interconnection in order to determine which schedules should be curtailed would only be possible if every transaction was tagged and therefore included in the IDC calculations. Reliability Coordinators in the Eastern Interconnection could access the IDC online and run flow studies based on various operating scenarios with all of the current energy schedules derived from the E-Tags. When an actual contingency occurred, the Reliability Coordinators could identify the constrained transmission line or corridor within the IDC, and the IDC would then identify which E-Tagged schedules should be curtailed in order to ease the loading on the restricted facilities.
E-Tag 1.7
NERC's E-Tag 1.7 Specification completely reworked the E-Tag platform from scratch. Some users said that it was so significant that it might have been more appropriate to have called it "E-Tag 2.0". For the first time, Extensible Markup Language (XML)XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
was utilized to format the data transferred between E-Tag applications, finally replacing the base CSV data transfer format based on its ancestral NERC Tag 1.0 spreadsheet/e-mail origins. The TSIN database was expanded to include generation and load points which were matched with PSEs that had rights to schedule them, and also included complex associations that enforced matched sets of PORs and PODs with TPs. E-Tag 1.7 also greatly expanded the time frame flexibility of an E-Tag by allowing extensions and modifications with comprehensive approval processes, layering of multiple OASIS requests for transmission rights, and also fully automated the tag curtailment functions from the IDC so that individual manual tag curtailments were no longer necessary.
Shortly after E-Tag 1.7 went online in 2002, the Western Electricity Coordinating Council (WECC)
Western Electricity Coordinating Council
The Western Electricity Coordinating Council was formed on April 18, 2002, from the merger of the Western Systems Coordinating Council which itself was formed on August 14, 1967, the Southwest Regional Transmission Association , and Western Regional Transmission Association...
implemented the WECC Unscheduled Flow (USF) Tool, which accomplished a similar automated curtailing capability for the Western Interconnection
Western Interconnection
The Western Interconnection is one of the two major alternating current power grids in North America. The other major wide area synchronous grid is the Eastern Interconnection...
that the IDC had done for the Eastern Interconnection.
The number of software choices for E-Tag software dwindled within the first few years to a handful of major players. The number of E-Tag users was strictly limited by the number of entities involved in E-Tagging, and the cost of complying with NERC E-Tag Specifications became prohibitive for any software company that did not already have significant market share or adequate financial backing. The added complexities of E-Tag 1.7 dealt a severe blow to most of the E-Tagging software providers, and within a year of E-Tag 1.7 going online, there was only one dominant E-Tag software provider remaining, which also provided all IDC and WECC USF services, though a few holdouts and customer-developed "in-house" E-Tag applications remain.
Version 1.7.097 of E-Tag was implemented on January 3, 2007.