A-1 Facilities DOG - See "Transmission Facilities Under ISO Operational Control ."

A-2 Facilities - See "Transmission Facilities Requiring ISO Notification ."

Actual Energy Withdrawals - Energy withdrawals which are either: (1) measured with a revenue-quality real-time meter; (2) assessed (in the case of LSEs serving retail customers where withdrawals are not measured by revenue-quality real-time meters) on the basis provided for in a Transmission Owner's retail access program; or (3) calculated (in the case of wholesale customers where withdrawals are not measured by revenue-quality real-time meters), until such time as revenue-quality real-time metering is available on a basis agreed upon by the unmetered wholesale customers.

Actual Net Interchange - 'ANI' - The actual net interchange for a Control Area. A positive value of ANI means that there is a net import of power into the Control Area. A negative value of ANI means that there is a net export of power out of the Control Area.

Administered Markets - The Day-Ahead Market and the Real-Time Market (collectively the "LBMP Markets") and any other market administered by the NYISO.

Adverse Conditions - Those conditions of the natural or man-made environment that threaten the adequate reliability of the NYS Power System, including, but not limited to, thunderstorms, hurricanes, tornadoes, solar magnetic flares and terrorist activities.

Affiliate - With respect to a person or entity, any individual, corporation, partnership, firm, joint venture, association, joint-stock company, trust or unincorporated organization, directly or indirectly controlling, controlled by, or under common control with, such person or entity. The term "control" shall mean the possession, directly or indirectly, of the power to direct the management or policies of a person or an entity. A voting interest of ten percent or more shall create a rebuttable presumption of control.

Alaskan Systems Coordination Council - 'ASCC'

Allegheny Power System - 'APS'

American National Standard Code for Information Interchange - 'ASCII'

American National Standards Institute - 'ANSI'

Ancillary Services [OATT] - Those services that are necessary to support the transmission of Capacity and Energy from resources to Loads while maintaining reliable operation of the NYS Transmission System in accordance with Good Utility Practice.

Ancillary Services [Services Tariff] - Services necessary to support the transmission of Energy from Generators to Loads, while maintaining reliable operation of the NYS Power System in accordance with Good Utility Practice and Reliability Rules. Ancillary Services include Scheduling, System Control and Dispatch Service; Reactive Supply and Voltage Support Service (or "Voltage Support Service"); regulation and Frequency Response Service (or "Regulation Service"); Energy Imbalance Service; Operating Reserve Service (including Spinning Reserve, 10-Minute Non-Synchronized Reserves and 30-Minute Reserves); and Black Start Capability.

Annual Transmission Costs - The total annual cost of the Transmission System for purposes of Network Integration and Point-to-Point Transmission Services shall be the amount specified in Attachment H until amended by the Transmission Owners or modified by the Commission.

Annual Transmission Revenue Requirement [Agreement] - The total annual cost for each Transmission Owner (other than LIPA) to provide transmission service subject to review and acceptance by the Commission.

Annual Transmission Revenue Requirement [OATT] - The total annual cost for each Transmission Owner (other than LIPA) to provide transmission service subject to review and acceptance by FERC or other authority.

Application [OATT] - A request to provide or receive service pursuant to the provisions of the NYISO Services Tariff, that includes all information reasonably requested by the NYISO.

Application [Services Tariff] - A request to provide or receive service pursuant to the provisions of the NYISO Services Tariff, that includes all information reasonably requested by the NYISO.

APS/PJM/VaPwr Joint Steering Group - 'APV'

Area Control Error - 'ACE' - The difference between the actual and scheduled interchange with other Control Areas, adjusted for frequency bias.

Asynchronous Transfer Mode - 'ATM'

Atlantic City Electric Company - 'AE'

At-Large Member - An entity that is entitled to hold a seat on a Committee as the representative of more than one party or entity.

Auction - See "Centralized TCC Auction"

Automated Mitigation Process - 'AMP'

Automatic Generation Control - 'AGC' - The automatic regulation of the power output of electric Generators within a prescribed range in response to a change in system frequency, or tie-line loading, to maintain system frequency or scheduled interchange with other areas within predetermined limits.

Automatic Voltage Regulator - 'AVR' - Equipment on a generator which allows it to provide voltage control capability.

Availability - A measure of time that generating facilities, transmission line or other facility is or was capable of providing service, whether or not it actually is in-service.

Available Generating Capacity - Generating Capacity that is on line to serve Load and/or provide Ancillary Services, or is capable of initiating start-up for the purpose of serving Transmission Customers or providing Ancillary Services, within thirty (30) minutes.

Available Transmission Capability - 'ATC' - A measure of the Transfer Capability remaining in the physical transmission network for further commercial activity over and above already committed uses. ATC is defined as the Total Transfer Capability, less Transmission Reliability Margin, less the sum of existing transmission commitments, (which includes retail customer service) less the Capacity Benefit Margin. The amount reserved to support existing transmission commitments is defined in the Existing Transmission Agreements and Existing Transmission Capacity for Native Load in Attachment L of the Open Access Transmission Tariff (OATT).



Back-buy - Process by which the LSEs can mitigate or avoid the deficiency payment by purchasing additional Installed Capacity from LSEs which have surplus Installed Capacity during the same Capability Period or from other qualified Installed Capacity Providers after the end of each Capability Period.

Backup Dispatch System - 'BDS' - A collection of procedures, hardware, and software components used by the NYISO and the TPs to reliably dispatch the NYCA when the NYISO EMS and critical communication interfaces are unavailable.

Back-Up Operation - The dispatch and scheduling of the NYS Power System performed by the Transmission Owners, pursuant to ISO Procedures, when the NYISO's ability to operate the NYS Power System has been impaired.

Balancing Market - The market or energy exchange resulting from the operation of the Security Constrained Dispatch (SCD).

Balancing Market Evaluation - 'BME' - An evaluation performed for the hour in which the dispatch occurs. The BME begins seventy-five (75) minutes before the beginning of the hour in which dispatch occurs. Based upon the Day-Ahead commitment and updated Load forecasts and Generator schedules, BME will assess new Bids for the Locational Based Marginal Pricing ("LBMP") Markets and requests for new Bilateral Transaction schedules for the Dispatch Hour to which the SCUC applies. BME will redispatch Internal Generators, schedule External Generators, schedule new Bilateral Transactions if feasible, update Desired Net Interchanges if needed, and Reduce or Curtail Bilateral Transactions with non-Firm and Firm Transmission Service as needed for the dispatch Hour for which the SCUC applies.

Baltimore Gas and Electric Company - 'BGE'

Base Point Signals - Electronic signals sent from the NYISO and ultimately received by Generators specifying the scheduled MW output for the Generator. Security Constrained Dispatch ("SCD") Base Point Signals are typically sent to Generators on a nominal five (5) minute basis. AGC Base Point Signals are typically sent to Generators on a nominal six (6) second basis.

Bid - Offer to purchase and/or sell Energy, Transmission Congestion Contracts and/or Ancillary Services at a specified price that is duly submitted to the NYISO pursuant to ISO Procedures.

Bid Price - The price at which the Supplier offering the Bid is prepared to provide the product or service, or the buyer offering the Bid is willing to pay to receive such product or service.

Bid Production Cost - Total cost of the Generators required to meet Load and reliability Constraints based upon Bids corresponding to the usual measures of Generator production cost (e.g., running cost and Minimum Generation and Start-Up Bid).

Bid Production Cost Guarantee - 'BPCG'

Bid/Post System - 'BSYS' - An electronic information system used to allow the posting of proposed transmission schedules and Bids for Energy and Ancillary Services by Market Participants for use by the NYISO and to allow the NYISO to post Locational Based Marginal Prices and schedules.

Bilateral Transaction - 'BT' - A Transaction between two or more parties for the purchase and/or sale of Capacity, Energy, and/or Ancillary Services other than those in the NYISO Administered Markets.

Billing and Accounting System - 'BAS'

Bit Map Protocol - 'BMP'

Black Start Capability - The ability of a generating unit or station to go from a shutdown condition to an operating condition and start delivering power without assistance from the power system.

B-Matrix - A mathematical model used to calculate transmission loss Penalty Factors. The elements of the B-Matrix are called B coefficients.

Board - See "Board of Directors".

Board of Directors - The governing body of the NYISO which is comprised of ten (10) persons (Directors) that are unaffiliated with any Market Participants, as described in the ISO Agreement.

Bulk Power System - 'BPS'

Bus - A conductor or group of conductors that serve as a common connection for two or more electric circuits within a station.

Business Issues Communitee - 'BIC' - A standing committee of the NYISO created pursuant to the ISO Agreement to establish rules related to business issues and provide a forum for discussion of those rules and issues.



Capability Period - Six (6) month periods which are established as follows: (1) from May 1 through October 31 of each year ("Summer Capability Period"); and (2) from November 1 of each year through April 30 of the following year ("Winter Capability Period"); or such other periods as may be determined by the Operating Committee of the NYISO. A Summer Capability Period followed by a Winter Capability Period shall be referred to as a "Capability Year". Each Capability Period shall consist of On-Peak and Off-Peak periods.

Capacity - The capability to generate or transmit electrical power, measured in megawatts ("MW").

Capacity Benefit Margin - 'CBM' - That amount of Total Transfer Capability reserved by the NYISO on the NYS Transmission System to ensure access to generation from interconnected systems to meet generation reliability requirements.

Capacity Limited Resource - 'CLR' - Generation with an UOL less than that available once an emergency has been activated

Central Hudson - 'CH' - A NY electric utility whose franchise area is located in the Mid-Hudson region.

Centralized TCC Auction - Centralized Transmission Congestion Contracts Auction - The process by which TCCs are released for sale for the Centralized Transmission Congestion Contracts Auction Period, through a bidding process administered by the NYISO or an auctioneer.

Centralized TCC Auction Period - The period equal to one or more whole Capability Periods, determined by the NYISO, for which the award of TCCs in the Auction is valid.

Class A Unit - A Generator or Dispatchable Load that participates in nominal five-minute SCD dispatch.

Class B Unit - A Generator or Dispatchable Load that is not participating in the nominal five-minute SCD dispatch, but offers to provide spinning reserves to the NYISO.

Clean Air Act Amendments of 1990 - 'CAAA 1990'

Cleveland Electric Illuminating Company - 'CEI'

Code of Conduct - The rules, procedures and restrictions concerning the conduct of the NYISO directors and employees, contained in Attachment F to the ISO Open Access Transmission Tariff.

Commission - The Federal Energy Regulatory Commission, or any successor agency.

Committee - The Management Committee, the Business Issues Committee or the Operating Committee of the NYISO, as the context may require.

Common Gateway Interface - 'CGI'

Common Management Information Protocol - 'CNHP'

Common Management Information Service Element - 'CMISE'

Competitive Opportunities Proceedings - 'COP'

Completed Application - An Application that satisfies all of the information and other requirements of the Tariff.

Computer and Data Advisory Subcommittee - 'CDAS'

Computer-Aided Software Engineering - 'CASE'

Confidential Information - Information and/or data that has been designated by an entity taking service under an ISO Tariff to be proprietary and confidential, provided that such designation is consistent with ISO Procedures and the applicable ISO Tariff, including the ISO Code of Conduct.

Congestion - A characteristic of the transmission system produced by a constraint on the optimum economic operation of the power system, such that the marginal price of Energy to serve the next increment of Load, exclusive of losses, at different locations on the transmission system is unequal.

Congestion Component - The component of the LBMP measured at a location or the Transmission Usage Charge between two locations that is attributable to the cost of transmission Congestion.

Congestion Rent - The opportunity costs of transmission Constraints on the NYS Transmission System. Congestion Rents are collected by the NYISO from Loads through its facilitation of the LBMP Market Transactions and the collection of Transmission Usage Charges from Bilateral Transactions, and paid to Primary Holders.

Congestion Rent Shortfall - A condition in which the Congestion Rent revenue collected by the NYISO over a defined time period is less than the amount of Congestion Rent revenue that the NYISO is obligated under the ISO OATT to pay out to the Primary Holders of TCCs.

Connectionless Network Service - 'CLNS'

Connectionless Transport Protocol - 'CLTP'

Consolidated Edison - 'ConEd' - A NY electric utility whose franchise area is located in NYC and Westchester, Co.


Constraint - An upper or lower limit placed on a variable or set of variables that are used by the NYISO in its SCUC, BME or SCD programs to control and/or facilitate the operation of the NYS Transmission System.

Contingency - An actual or potential unexpected failure or outage of a system component, such as a Generator, transmission line, circuit breaker, switch or other electrical element. A Contingency also may include multiple components, which are related by situations leading to simultaneous component outages.

Continuous Rating - See "Normal Rating."

Contract Establishment Date - The date, listed in Attachment L, on which the listed existing agreements which are the source of Grandfathered Rights and Grandfathered TCCs were executed.

Contract For Differences - 'CFD' - A contract between a buyer and seller agreeing upon an energy price at a specific location on the grid. The participants buy and sell at LBMP and settle the difference from the agreed upon price after the fact.

Control - The possession, directly or indirectly, of the power to direct the management or policies of a person or an entity. A voting interest of ten percent or more shall create a rebuttable presumption of control. There is a rebuttable presumption that an entity controls another entity if, either directly or indirectly: (i) an entity has ten percent or more of the ownership interest of another entity; or (ii) an entity has the ability to exercise ten percent or more of the voting interests of another entity, including an organization, association or group of entities authorized to serve as an At-Large Member of a Committee or to appoint an At-Large Member of a Committee.

Control Area - An electric power system or combination of electric power systems to which a common automatic generation control scheme is applied in order to: (1) match, at all times, the power output of the Generators within the electric power system(s), and capacity and energy purchased from entities outside the electric power system(s), with the Load within the electric power system(s); (2) maintain scheduled interchange with other Control Areas, within the limits of Good Utility Practice; (3) maintain the frequency of the electric power system(s) within reasonable limits in accordance with Good Utility Practice; and (4) provide sufficient generating capacity to maintain operating reserves in accordance with Good Utility Practice.

Control Area Services - Services provided by the NYISO under the ISO Services Tariff related to the NYISO's responsibilities as the Control Area operator for the NYCA.

Control Performance Standard - 'CPS'

Cost Management Technique - 'CMT'

Curtailment or Curtail - A reduction in Firm or non-Firm Transmission Service in response to a transmission capacity shortage as a result of system reliability conditions.

Customer [Agreement] - An entity taking services under the ISO Services Tariff.

Customer [OATT, Services Tariff] - An entity which has complied with the requirements contained in the ISO Services Tariff, including having signed a Service Agreement, and is qualified to utilize the Market Services and the Control Area Services provided by the NYISO under the ISO Services Tariff; provided, however, that a party taking services under the Tariff pursuant to an unsigned Service agreement filed with the Commission by the NYISO shall be deemed a Customer.



Data Access Integration Services - 'DAISTM'

Day-Ahead - Nominally, the twenty-four (24) hour period directly preceding the Dispatch Day, except when this period may be extended by the NYISO to accommodate weekends and holidays.

Day-Ahead LBMP - The LBMPs calculated based upon the NYISO's Day-Ahead Security Constrained Unit Commitment process.

Day-ahead Market - 'DAM' - The NYISO Administered Market in which Capacity, Energy and/or Ancillary Services are scheduled and sold Day-Ahead consisting of the Day-Ahead scheduling process, price calculations and Settlements.

Decremental Bid - A monotonically increasing bid curve provided by an entity engaged in a Bilateral Transaction to indicate the LBMP below which that entity is willing to reduce its Generator's output or have its Transmission Service Curtailed, and purchase Energy in the LBMP Markets. If Decremental Bids are not voluntarily provided by such entities, the NYISO will enter a default Decremental Bid.

Delivering Party - The entity supplying Capacity and Energy to be transmitted at Point(s) of Receipt.

Delivery Factor - The incremental effect of transmission losses. Delivery Factor is the inverse of Penalty Factor.

Delmarva Power && Light Company - 'DPL'

Demand Side Resources - 'DSM' - Resources that result in the reduction of a Load in a responsive and measurable manner and within time limits established in the ISO Procedures.

Dependable Maximum Net Capability - 'DMNC' - The sustained maximum net output of a Generator, as demonstrated by the performance of a test or through actual operation, averaged over a continuous time period as defined in the ISO Procedures.

Designated Agent - Any entity that performs actions or functions on behalf of the Transmission Owner, an Eligible Customer, or the Transmission Customer required under the Tariff.

Desired Net Interchange - 'DNI' - A mechanism used to set and maintain the desired Energy interchange (or transfer) between two Control Areas; it is scheduled ahead of time and can be changed only manually in real-time.

Dipute Resolution Administrator - 'DRA' - An individual hired by the NYISO to administer the Dispute Resolution Process established in the ISO Tariffs and ISO Agreement.

Direct Assignment Facilities - Facilities or portions of facilities that are constructed by the Transmission Owner(s) for the sole use/benefit of a particular Transmission Customer requesting service under the Tariff. Direct Assignment Facilities shall be specified in the Service Agreement that governs service to the Transmission Customer and shall be subject to Commission approval.

Direct Customer - 'DC' - A Market Participant registered and qualified to do business in the NY wholesale market directly through the ISO.

Direct Sale - The sale of TCCs directly to a buyer by the Primary Owner through a non-discriminatory auditable sale conducted on the NYISO's OASIS, in compliance with the requirements and restrictions set forth in Commission Order Nos. 888 et seq. and 889 et seq.

Dispatch Coordination Advisory Subcommittee - 'DCAS'

Dispatch Day - The twenty-four (24) hour period commencing at the beginning of each day (0000 hour).

Dispatchable - A Generator or Load that is capable of responding to real-time control from the NYISO.

Dispatcher Training Simulator - 'DTS'

Dispute Resolution Committee - 'DRC'

Dispute Resolution Process - 'DRP' - The procedures: (1) described in the ISO Tariffs and the ISO Agreement that are used to resolve disputes between Market Participants and the NYISO involving services provided under the ISO Tariffs (excluding applications for rate changes or other changes to the ISO Tariffs or rules relating to such services); and (2) described in the ISO/NYSRC Agreement that are used to resolve disputes between the ISO and NYSRC involving the implementation and/or application of the Reliability Rules.

Distributed Computing Environment - 'IDCE'

Distributed Name Service - 'DNS'

Distribution Factor - 'DFAX'

Drawing Exchange Format - 'DXF'



East Central Area Reliability Coordination Agreement - 'ECAR'

Economic Dispatch Control - 'EDC'

Effective Forced Outage Rate on Demand - 'EFORd'

Electric Power Research Institute - 'EPRI'

Electric Reliability Council of Texas - 'ERCOT'

Electronic Billing Information - 'EBI' - Monthly billing data to date provided daily by the ISO to all Market Participants.

Electronic Data Interchange - 'EDI'

Eligible Customer - (i) Any electric utility (including the Transmission Owner and any power marketer), Federal power marketing agency, or any person generating Energy for sale or resale is an Eligible Customer under the Tariff. Electric energy sold or produced by such entity may be electric energy produced in the United States, Canada or Mexico. However, with respect to transmission service that the Commission is prohibited from ordering by Section 212(h) of the Federal Power Act, such entity is eligible only if the service is provided pursuant to a state requirement that the Transmission Owner offer the unbundled transmission service, or pursuant to a voluntary offer of such service by the Transmission Owner. (ii) Any retail customer taking unbundled transmission service pursuant to a state requirement that the Transmission Owner offer the transmission service, or pursuant to a voluntary offer of such service by the Transmission Owner, is an Eligible Customer under the Tariff.

Emergency - Any abnormal system condition that requires immediate automatic or manual action to prevent or limit loss of transmission facilities or Generators that could adversely affect the reliability of an electric system.

Emergency Response Rate - 'ERR' - The rate of load that a generating unit can achieve under reserve pick-up conditions, expressed in MW/min. The ERR must be greater than or equal to the unit normal response rate (NRR) and is required for dispatch and reserve bidding.

Emergency State - The state that the NYS Power System is in when an abnormal condition occurs that requires automatic or immediate, manual action to prevent or limit loss of the NYS Transmission System or Generators that could adversely affect the reliability of the NYS Power System.

Emergency Transfer Criteria - 'ETC'

Empire State Electric Energy Research Corporation - 'ESEERCO'

Energy - A quantity of electricity that is Bid, produced, purchased, consumed, sold, or transmitted over a period of time, and measured or calculated in megawatt hours.

Energy Information Administration - 'EIA'

Energy Limited Resource - 'ELR' - Operating limits reduced for lack of energy resource [wind, water], minimum down times or environmental concerns. Subset of CLR

Energy Management System - 'EMS'

Energy Planning Strategy - 'EPS'

Energy Service Company - 'ESCO' - A load serving entity, a retail load aggregator or a provider of comprehensive energy services or a formal group of such entities, serving customers in New York State.

Environmental Party - An environmental organization that is certified by the ISO Board as a non-Market Participant and is a Party to the ISO Agreement.

Excess Congestion Rents - Congestion revenues collected by the NYISO that are in excess of its payment obligations to those parties with which it has such a financial obligation. Excess Congestion Rents may arise if Congestion occurs and if the Transfer Capability of the transmission system is not exhausted by the set of TCCs and Grandfathered Rights that have been allocated at the completion of the Centralized TCC Auction.

Existing Transmission Agreement - 'ETA' - An agreement between two or more Transmission Owners, or between a Transmission Owner and another entity, that was executed and was in effect on the date that the NYISO commenced operations, including amendments and superseding issues thereof (including service agreements) under individual Transmission Owners open access tariffs (provided that the Points of Injection ("POI" ) and Points of Withdrawal ("POW") and contract amounts do not change). Existing Transmission Agreements are either Transmission Wheeling Agreements or Transmission Facility Agreements, and are listed in the ISO OATT.

Existing Transmission Capacity for Native Load - Transmission capacity reserved on a Transmission Owner's transmission system to serve the Native Load Customers of the current Transmission Owners (as of the filing date of the original ISO Tariff - January 31, 1997). This includes transmission capacity required: (1) to deliver the output from operating facilities located out of a Transmission Owner's Transmission District; (2) to deliver power purchased under power supply contracts; and (3) to deliver power purchased under third party agreements (i.e., Non-Utility Generators). Existing Transmission Capacity for Native Load is listed in Attachment L of the ISO OATT.

Exports - Purchases from the LBMP Market where the Energy is delivered to a NYCA interconnection with another Control Area.

External - An entity (e.g., Supplier, Transmission Customer) or facility (e.g., Generator, Interface) located outside the Control Area being referenced or between two or more Control Areas. Where a specific Control Area is not referenced, the NYCA is the intended reference.

External Transactions - Purchases, sales or exchanges of Energy, Capacity or Ancillary Services for which either the Point of Injection ("POI") or Point of Withdrawal ("POW") or both are located outside the NYCA (i.e., Exports, Imports or Wheels Through).

Extraordinary Corrective Action - 'ECA'



Facilities Study - An engineering study conducted by the NYISO and/or a Transmission Owners to determine the required modifications to the Transmission Owner's Transmission System, including the cost and scheduled completion date for such modifications, that will be required to provide the requested facilities.

Federal Energy Regulatory Commission - 'FERC' - The federal agency responsible with overseeing and regulating the wholesale electric market within the US.

Federal Power Act - 'FPA' - The Federal Power Act, as may be amended from time-to-time (See, 16. U.S.C. .. 796 et seq.).

Fiber Distributed Data Interface - 'FDDI'

File Transfer, Access and Management - 'FTAM'

File Transport Protocol - 'FTP'

Firm Point-To-Point Transmission Service - Transmission Service under this Tariff that is scheduled between specified Points of Receipt and Delivery pursuant to Part II of this Tariff. Firm Point-To-Point Transmission Service is service for which the Transmission Customer has agreed to pay the Congestion associated with its service. A Transmission Customer may fix the price of Congestion associated with its Firm Point-To-Point Transmission Service by acquiring sufficient TCCs with the same Points of Receipt and Delivery as its Transmission Service.

Firm Transmission - Service Transmission service requested by a Transmission Customer willing to pay Congestion Rent.

First Contingency Total Transfer Capability - 'FCTTC'

First Settlement - The process of establishing binding financial commitments on the part of Customers participating in the Day-Ahead Market based on Day-Ahead LBMP.

Flowgate - Interface on which the Energy flow is monitored and controlled to insure reliability of the system.

Forced Outage - An outage that results from conditions affecting an element requiring that it be removed from service.

Frequency Bias - A value, usually given as MW/0.1 HZ, associated with a control area which relates the difference between scheduled and actual frequency to the amount of generation required to correct the difference.



Gamma - Mathematical symbol for marginal costs for losses and constraints, expressed as $/MWh.

GAPP Advocate Task Force - 'GATF'

GAPP Exectuive Steering Committee - 'GESE'

Gas Turbine - 'GT'

General Agreement on Parallel Paths - 'GAPP'

General Public Utilities Corporation - 'GPU'

Generating Availability Data System - 'GADS'

Generation Company - 'GENCO'

Generation Shift - 'G-Shift'

Generation Shift Factor - 'GF' - The incremental affect on a given constraint due to a shift in generation (MW) at a specified bus.

Generator - A facility capable of supplying Energy, Capacity and/or Ancillary Services that is accessible to the NYCA or the Energy, Capacity and/or Ancillary Services from such facilities.

Generator Classes - The type of Generator (e.g., nuclear, gas turbine, fossil, hydro) which is used by the NYISO to determine criteria that must be met for that Generator to qualify as a source of Installed Capacity.

Geo-Magnetic Distrubance - 'GMD'

Giga Watt - 'GW' - 1000 MW - See "Power"

Giga Watt Hour = 1000 MWH - 'GWH' - 1000 MHW - See "Energy"

Good Utility Practice - Any of the practices, methods or acts engaged in or approved by a significant portion of the electric utility industry during the relevant time period, or any of the practices, methods or acts which, in the exercise of reasonable judgment in light of the facts known at the time the decision was made, could have been expected to accomplish the desired result at a reasonable cost consistent with good business practices, reliability, safety and expedition. Good Utility Practice is not intended to be limited to the optimum practice, method, or act to the exclusion of all others, but rather to delineate acceptable practices, methods, or acts generally accepted in the region.

Government Bonds - Tax-exempt bonds issued by the New York Power Authority pursuant to Section 103 and related provisions of the Internal Revenue Code, 26 U.S.C. . 103.

Grandfathered - 'GF' - Any agreement or contract signed before the formation of the NY market which remains in affect as a result of an exercised choice.

Grandfathered Rights - The transmission rights associated with: (1) Modified Wheeling Agreements; (2) Transmission Facility Agreements with transmission wheeling provisions; (3) Third Party Transmission Wheeling Agreements ("TWA") where the party entitled to exercise the transmission rights associated with such Agreements has chosen, as provided in the Tariff, to retain those rights rather than to convert those rights to TCCs; and (4) Existing Transmission Capacity for Native Load, Table 3 of Attachment L to the ISO OATT. Upon the expiration or termination of Grandfathered Rights, the associated transmission capacity is converted to Residual Transmission Capacity.

Grandfathered TCCs - The TCCs associated with: (1) Modified Wheeling Agreements; (2) Transmission Facility Agreements with transmission wheeling provisions; (3) Third Party ("TWA") where the party entitled to exercise the transmission rights associated with such Agreements has chosen, as provided by the Tariff, to convert those rights to TCCs; and (4) Existing Transmission Capacity for Native Load, Table 3 of attachment L to the ISO OATT.

Graphics Interface Format - 'GIF'



High-level Data Link Control - 'HDLC'

Host Control Area - 'HCA'

Hour Ahead Market (evaluation only) - 'HAM'

Hour-Ahead Bid - A Bid submitted at least seventy-five (75) minutes before the dispatch hour to which it applies.

Hydro One - 'HO'

Hydro Quebec - 'HQ'

Hypertext Markup Language - 'HTML'

Hypertext Transport Protocol - 'HTTP'



Imports - Transmission Service originating within another Control Area and wheeling into the NYCA.

Imputed Revenue - The Congestion Rents that owners of Grandfathered Rights do not have to pay due to their own use of those Grandfathered Rights.

Inadvertent Energy Accounting - The accounting performed to track and reconcile the difference between net actual Energy interchange and scheduled Energy interchange of a Control Area with adjacent Control Areas.

Inadvertent Interchange - The difference between the scheduled and actual energy interchange over a Control Area boundary (DNI-ANI). A positive value of Inadvertent Interchange means that the Control Area is over-generating. A negative value of Inadvertent Interchange means that the Control Area is under-generating.

Incremental Bid - A monotonically increasing Bid curve with a finite number of break points (currently six break points), that indicates an entity's willingness to supply Energy at certain prices to the NYISO Administered LBMP Markets.

Incremental TCC - A set of point-to-point Transmission Congestion Contract(s) allocated to the Transmission Customer or Transmission Owner that is paying for a Network Upgrade. Incremental TCCs are point-to-point TCCs that derive from the increase or decrease in Interface Total Transfer Capability resulting from the Network Upgrade.

Independent Electricity Market Operator - 'IMO'

Independent Power Producer - 'IPP' - See "Non-Utility Generator".

Independent System Operator - 'ISO' - The New York Independent System Operator, Inc., a not-for-profit corporation established pursuant to the ISO Agreement.

Industry Sector Group or Industry Sector Groups - As the context may require, individually or collectively, Transmission Owners, Wholesale Parties (including Wholesale Marketers and Generators) and Retail Parties (including ESCOs, Retail Marketers, large end users, municipal and cooperative systems, representatives of residential and small commercial consumers and representatives of industrial and large commercial consumers).

Installed Capacity - 'ICAP'

Installed Capacity - A Generator or Load facility that complies with the requirements in the Reliability Rules and is capable of supplying and/or reducing the demand for Energy in the NYCA for the purpose of ensuring that sufficient Energy and Capacity are available to meet the Reliability Rules.
The Installed Capacity requirement, established by the NYSRC, includes a margin of reserve in accordance with the Reliability Rules.

Installed Capacity Deficiency Charge - The monetary penalty paid by LSEs found deficient in their Installed Capacity requirements at the end of the Back-buy grace period of each Capability Period. This penalty accrues to the NYISO rate schedule 1 account of the NYISO Tariff.

Institute of Electrical and Electronics Engineers - 'IEEE'

Integrated Services Digital Network - 'ISDN'

Interactive Relay Chat - 'IRC'

Interchange - Energy transferred from one control area to another.

Interchange Distribution Calculator - 'IDC'

Interchange Scheduler Plus - 'IS+'

Interconnected Operations Services - 'IOS'

Interconnection or Interconnection Points - 'IP' - The point(s) at which the NYCA connects with a distribution system or adjacent Control Area. The IP may be a single tie line or several tie lines that are operated in parallel.

Inter-Control Center Communications Protocol - 'ICCP'

Interface - A defined set of transmission facilities that separate Load Zones and that separate the NYCA from adjacent Control Areas.

Interface MW - Mile Methodology - The procedure used to allocate Residual TCCs, revenues from the sale of certain TCCs, and Excess Congestion Rents between the Transmission Owners as described in Attachment K to the ISO OATT.

Interface MW-Mile - 'IMWM'

Interim Unit Commitment - 'UCI'

Internal - An entity (e.g., Supplier, Transmission Customer) or facility (e.g., Generator, Interface) located within the Control Area being referenced. Where a specific Control Area is not referenced, internal means the NYCA.

Internal Transactions - Purchases, sales or exchanges of Energy, Capacity or Ancillary Services where the Generator and Load are located within the NYCA.

International Electrotechnical Commission - 'IEC'

International Electrotechnical Commission Technical Committee 57 - 'IEC TC57'

International Organization for Standardization - 'ISO'

International Telecommunication Union - 'ITU'

International Telegraph and Telephone Consultative Committee - 'CCITT'

Internet Network Information Center - 'InternetNIC'

Internet Protocol Address - 'IP'

Internet Protocol Control Protocol - 'IFCP'

Inter-regional Transmission Coordinating Forum - 'ITCF'

Interruptible Load Resources - A Load that is obligated under a contract to be interrupted when required by the NYISO. Such a Load must demonstrate that it is capable of quantifiable reduction in consumption in response to the NYISO's instructions.

Interruption - A reduction in non-Firm Transmission service due to economic reasons pursuant to Section 14.7.

Inter-Utility Data Exchange Committee - 'IDEC'

Investor Owned utilities - 'IOU'

Investor-Owned Transmission Owners - At the present time these include: Central Hudson Gas & Electric Corporation, Consolidated Edison Company of New York, Inc., New York State Electric & Gas Corporation, Niagara Mohawk Power Corporation, Orange and Rockland Utilities, Inc., and Rochester Gas and Electric Corporation.

ISO Administered Markets - The Day-Ahead Market and the Real-Time Market (collectively the LBMP Markets) and any other market administered by the NYISO.

ISO Market Power Monitoring Program - The monitoring program approved by the Commission and administered by the NYISO designed to monitor the possible exercise of market power in NYISO Administered Markets.

ISO Procedures - The procedures adopted by the NYISO in order to fulfill its responsibilities under the ISO OATT, the ISO Services Tariff and the ISO Related Agreement, and consistent with the Reliability Rules.

ISO Related Agreements - Collectively, the ISO Agreement, the NYSRC Agreement, the ISO/NYSRC Agreement and the ISO/TO Agreement.

ISO Services Tariff - The ISO Market Administration and Control Area Services Tariff.

ISO Tariffs - The ISO OATT and the ISO Services Tariff, collectively.

ISO/NYSRC Agreement - Independent System Operator/New York State Reliability Council Agreement -The agreement between the NYISO and the New York State Reliability Council governing the relationship between the two organizations.

ISO/TO Agreement - Independent System Operator/Transmission Owner Agreement - The agreement that establishes the terms and conditions under which the Transmission Owners transferred to the NYISO Operational Control over designated transmission facilities.



Joint Photographic Experts Group - 'JPEG'



KiloVolts - 'kV' - 1000 Volts see "Volts"



L(sub d) - A control performance parameter expressed in MW. It specifies that the average Pool Control Error for all ten minute periods must be within plus or minus Ld . Ld is defined as the greatest Pool load change on the peak day times 2.5% plus 5 MW based on historical data.

Lagging MVArs - Mega-Volt-Amperes - reactive (MVArs) that are generated out of a generator and into the NY Transmission system and are normally denoted with a positive (+) sign.

Lambda - Mathematical symbol for incremental cost, expressed as $/MWh.

LBMP Load Zone - See "Load Zone."

LBMP Markets - A term that collectively refers to both the Real-Time Market and the Day-Ahead Market.

LBMP Transition Period - A five year period commencing with the start date of the implementation of both a Real-time and Day-Ahead Market during which the Investor-Owned Transmission Providers, by mutual agreement, will be subject to LBMP Transition Period Payments and other measures to mitigate transmission cost shifting.

LBMP Transition Period Payments - 'LTPP' - Fixed monthly payments, as detailed in Attachment K of the ISO OATT, made between or among the Investor-Owned Transmission Owners to mitigate transmission cost-shifting as the competitive market is introduced for Energy and transmission pricing.

Leading MVArs - Mega-Volt-Amperes - reactive (MVArs) that are absorbed by a generator out of the NY Transmission system and are normally denoted with a negative (-) sign.

LIPA Tax Exempt Bonds - Obligations of the Long Island Power Authority, the interest on which is not included in gross income under the Internal Revenue Code.

Load - A term that refers to either a consumer of Energy or the amount of Energy (MWh) or demand (MW) consumed by certain consumers.

Load Flow - See "Power Flow".

Load Ratio Share - The ratio of an LSE's Load to Load within the NYCA during a specified time period.

Load Serving Entity - 'LSE' - An entity, including a municipal electric system and an electric cooperative, authorized or required by law, regulatory authorization or requirement, agreement, or contractual obligation to supply Energy, Capacity and/or Ancillary Services to retail customers located within the NYCA, including an entity that takes service directly from the NYISO to supply its own load in the NYCA.

Load Shedding - The systematic reduction of system demand by temporarily decreasing Load in response to Transmission System or area Capacity shortages, system instability, or voltage control considerations under Part III of the Tariff.

Load Zone - One (1) of eleven (11) geographical areas located within the NYCA that is bounded by one (1) or more of the fourteen (14) New York State Interfaces. During the implementation of the LBMP Markets, all Loads located within the same Load Zone pay the same Day-Ahead LBMP and the same Real-Time LBMP for Energy purchased in those markets.

Local Area Network - 'LAN'

Local Area Transmission System Facilities - Transmission System facilities not designated as either "Transmission Facilities Under NYISO Operational Control" or as "Transmission Facilities Requiring NYISO Notification."

Local Furnishing Bonds - Tax-exempt bonds issued by a Transmissions Owner under an agreement between the Transmission Owner and the New York State Research and Development Authority ("NYSERDA"), or its successor, or by a Transmission Owner itself, and pursuant to Section 142(f) of the Internal Revenue Code, 26 U.S.C. . 142(f).

Local Furnishing Bonds - Tax-exempt bonds issued by a Transmissions Owner under an agreement between the Transmission Owner and the New York State Energy Research and Development Authority ("NYSERDA"), or its successor, or by a Transmission Owner itself, and pursuant to Section 142(f) of the Internal Revenue Code, 26 U.S.C. . 142(f).

Local Reliability Rule - 'LRR' - A Reliability Rule established by a Transmission Owner, and adopted by the NYSRC, to meet specific reliability concerns in limited areas of the NYCA, including without limitation, special conditions and requirements applicable to nuclear plants and special requirements applicable to the New York City metropolitan area.

Locality - A single LBMP Load Zone or set of adjacent LBMP Load Zones within one Transmission District, and within which a minimum level of Installed Capacity must be maintained.

Locational Based Marginal Pricing - 'LBMP' - A pricing methodology under which the price of Energy at each location in the NYS Transmission System is equivalent to the cost to supply the next increment of Load at that location (i.e., the short-run marginal cost). The short-run marginal cost takes generation Bid Prices and the physical aspects of the NYS Transmission System into account. The short-run marginal cost also considers the impact of Out-of-Merit Generation (as measured by its Bid Price) resulting from the Congestion and Marginal Losses occurring on the NYS Transmission System which are associated with supplying an increment of Load. The term LBMP also means the price of Energy bought or sold in the LBMP Markets at a specific location.

Locational Installed Capacity Requirement - A determination of the NYISO of that portion of the state-wide Installed Capacity requirement that must be electrically located within a Locality in order to ensure that sufficient Energy and Capacity are available in that Locality and that appropriate reliability criteria are met.

Long Island Power Authority - 'LIPA'

Long Term Emergency Rating - 'LTE' - The maximum loading of electrical equipment which can be sustained for up to four hours during a twenty-four hour period based on nominal ambient conditions and nominal load pattern. Usually two values are used during the year: LTE-summer and LTE-winter.

Long-Term Firm Point-To-Point Transmission Service - Firm Point-to-Point Service, the price of which is fixed for a long term by a Transmission Customer acquiring sufficient TCCs with the same Points of Receipt and Delivery as its Transmission Service.

Loss of Load Expectation - 'LOLE'

Losses, Transmission - The power that is lost as dissipated heat when power flows in transmission lines and transformers.

Lost Opportunity Cost - 'LOC' - The foregone profit associated with the provision of Ancillary Services, which is equal to the product of: (1) the difference between (a) the Energy that a Generator could have sold at the specific LBMP and (b) the Energy sold as a result of reducing the Generator's output to provide an Ancillary Service under the direction of the NYISO; and (2) the LBMP existing at the time the Generator was instructed to provide the Ancillary Service, less the Generator's Energy bid for the same MW segment.

Lower Operating Limit - 'LOL' - Lower Operating Limit of a generator under normal operating conditions and less than the full operating range of the bid curve



MAAC-ECAR-NPCC - 'MEN'

Major Emergency State - 'ME' - A situation usually accompanied by abnormal frequency, abnormal voltage and/or equipment overloads that create a serious risk that the reliability of the NYS Power System could be adversely affected.

Management Committee - One (1) of three (3) standing committees, as described in the NYISO Agreement. The Management Committee reports directly to the NYISO Board of Directors.

Mandatory Control Mode - See "Mandatory"

Mandatory Control Mode - A mode of Automatic Generation Control where the Member system's Satellite Control Error may be in a direction opposing the Pool Control Error, but will bring their generation in line with the base points produced by Security Constrained Dispatch.

Manual Dispatch - A dispatch of the NYS Transmission System performed by the NYISO when the NYISO's SCD is unavailable.

Manual Dispatch System - 'MDS'

Marginal Cost - The cost (or the increase in total cost) required to produce one additional unit of output (or the reduction in the total cost from producing one unit less). The Marginal Cost includes all incremental system costs, including, without limitation, Out-of-Merit generation costs resulting from transmission system congestion and losses, associated with supplying an increment of Load.

Marginal Losses - The NYS Transmission System Real Power Losses associated with each additional MWh of consumption by Load, or each additional MWh transmitted under a Bilateral Transaction as measured at the Points of Withdrawal.

Marginal Losses Component - The component of LBMP at a bus that accounts for the Marginal Losses, as measured between that bus and the Reference Bus.

Market Clearing Price - 'MCP'

Market Information System - 'MIS' - The NYISO Market Information System (MIS) is the primary interface between users and the NYISO. Direct Customers use MIS to submit bids, schedules, forecasts, and other information to the NYISO. The NYISO uses MIS to post market results and other information for Direct Customers and other users.

Market Mitigation Measures - 'MMM'

Market Monitoring and Performance Unit - 'MMPU'

Market Monitoring Unit - 'MMU'

Market Participant - 'MP' - An entity, excluding the NYISO, that produces, transmits, sells, and/or purchase for resale Capacity, Energy and Ancillary Services in the Wholesale Market. Market Participants include: Transmission Customers under the ISO OATT, Customers under the ISO Services Tariff, Power Exchanges, Transmission Owners, Primary Holders, LSEs, Suppliers and their designated agents. Market Participants also include entities buying or selling TCCs.

Market Participant Administrator Cadre Training - 'MPACT'

Market Power Monitoring Program - The program approved by the Commission and implemented by the NYISO that is intended to review and analyze data with respect to the possible exercise of market power in an ISO Administered Market.

Market Services - Services provided by the NYISO under the ISO Services Tariff related to the ISO Administered Markets for Energy, Capacity and Ancillary Services.

Master Genertion File - 'MGF'

Maximum Generator Pick-Up - When ordered by the NYISO SPD, Transmission Providers immediately increase and/or start all capable generation at Emergency Response Rates until ordered to stop. This order can be made on a statewide or geographical basis.

MegaVars - 'MVAr' - See "Reactive Power"

MegaWatt - 'MW' - See "Power"

MegaWatt Hour - 'MWH' - See "Energy"

Member - The individual that is entitled to hold a seat on a NYISO Committee as a representative of a Party or Parties or the representative of an entity authorized to hold a seat on a Committee under the terms of this Agreement.

Member Systems - The eight Transmission Owners that comprise the membership of the New York Power Pool.

Mid- Continent Area Power Pool - 'MAPP'

Mid-America Interconnected Network - 'MAIN'

Mid-Atlantic Area Council - 'MAAC'

Minimum Generation and Start-Up Bid - The payment required by a Supplier to bring a Generator to and operate at its minimum safe and stable operating level.

Modified Wheeling Agreement - 'MWA' - A Transmission Agreement in existence, as amended, between Transmission Owners, that is associated with existing Generators or power supply contracts, that will be modified effective upon LBMP implementation. The terms and conditions of the MWA will remain the same as the original agreement, except as noted in the ISO OATT.



National Energy Policy Act of 1992 - 'NEPA 1992'

Native Load - Existing and reasonably-forecasted Energy requirements of Native Load Customers which a Transmission Provider has the obligation to serve by statute, franchise, contract or federal or state policy or regulation.

Native Load Customers - The wholesale and retail power customers of the Transmission Owners on whose behalf the Transmission Owners, by statute, franchise, regulatory requirement, or contract, have undertaken an obligation to construct and operate the Transmission Owners' systems to meet the reliable electric needs of such customers.

Native Load TCCs - TCCs associated with Existing Transmission Capacity for Native Load.

NERC Distrubance Control Standard - 'DCS'

NERC Transaction Priorities - The reservation and scheduling priority applied to a Transaction under the NERC Transmission Loading Relief Procedure.

NERC Transmission Loading Relief Procedure - 'NERC TLR'

Network Customer - An entity receiving Transmission Service pursuant to the terms of the NYISO's Network Integration Transmission Service under Part III of the Tariff.

Network Integration Transmission Service - The Transmission Service provided under Part III of the Tariff.

Network Load - The Load that a Network Customer designates for Network Integration Transmission Service under Part III of the Tariff. The Network Customer's Network Load shall include all Load served by the output of any Network Resources designated by the Network Customer. A Network Customer may elect to designate less than its total Load as Network Load but may not designate only part of the Load at a discrete Point of Delivery. Where an Eligible Customer has elected not to designate a particular Load at discrete points of delivery as Network Load, the Eligible Customer is responsible for making separate arrangements under Part II of the Tariff for any Point-To-Point Transmission Service that may be necessary for such non- designated Load.

Network Operating Agreement - An executed agreement that contains the terms and conditions under which the Network Customer shall operate its facilities and the technical and operational matters associated with the implementation of Network Integration Transmission Service under Part III of the Tariff. For Eligible Customers that take service under the ISO Services Tariff, that Tariff shall function as their Network Operating Agreement.

Network Operating Committee - The NYISO Operating Committee will serve this function.

Network Resource - Any generating resource that provides Installed Capacity to the NYCA designated under the Network Integration Transmission Service provisions of the Tariff. Network Resources do not include any resource, or any portion thereof, that is committed for sale to third parties or otherwise cannot be called upon to meet the Network Customer's Network Load on a non-interruptible basis.

Network Time Protocol - 'NTP'

Network Upgrade Agreement - An agreement entered into between a Transmission Customer and a Transmission Owner that identifies the rights and obligations of each party with respect to the Network Upgrade, as described in this Tariff.

Network Upgrades - Modifications or additions to transmission facilities that are integrated with and support the Transmission Owner's overall Transmission System for the general benefit of all users of such Transmission System.

New England Electric Services - 'NEES'

New England Indepenedent System Operator - 'NEISO'

New England Power Pool - 'NE'

New England Power Pool - 'NEPOOL'

New York Control Area - 'NYCA' - The Control Area that is under the control of the NYISO which includes transmission facilities listed in the ISO/TO Agreement Appendices A-1 and A-2, as amended from time-to-time, and Generation located outside the NYS Power System that is subject to protocols (e.g., telemetry signal biasing) which allow the NYISO and other Control Area operator(s) to treat some or all of that Generation as though it were part of the NYS Power System.

New York Independent System Operator - 'NYISO' - Us. The organization responsible for the reliable coordination and operation of NY bulk power system as well as the facilitator of the NY wholesale market.

New York Market Orientation Course - 'NYMOC' - The 3 day training course offered by the NYISO intended to introduce participants to the varied aspects of the NY market.

New York Power Authority - 'NYPA' - The statewide power authority chartered by the NYS Legislature and owner of a significant portion of NY's generation and bulk transmission assets.

New York Power Authority Transmission Access Charge - 'NTAC' - A surcharge on all Energy Transactions designed to recover the Annual Transmission Revenue Requirement of NYPA which cannot be recovered through its TSC, TCCs, or other transmission revenues, including, but not limited to, its ETA revenues. This charge will be assessed to all Load statewide, as well as Transmission Customers in Wheels Through and Exports.

New York Power Exchange - 'NYPE'

New York Power Pool - 'NYPP' - An organization established by agreement (the "New York Power Pool Agreement") made as of July 21, 1966, and amended as of July 16, 1991, by and among Central Hudson Gas & Electric Corporation, Consolidated Edison Company of New York, Inc., Long Island Lighting Company, New York State Electric & Gas Corporation, Niagara Mohawk Power Corporation, Orange and Rockland Utilities, Inc., Rochester Gas and Electric Corporation, and the Power Authority of the State of New York. LIPA became a Member of the NYPP on May 28, 1998 as a result of the acquisition of the Long Island Lighting Company by the Long Island Power Authority.

New York Public Service Law - 'PSL' - The New York Public Service Law, N.Y. Pub. Serv. Law . 1 et seq. (McKinney 1989 & Supp. 1997-98).

New York State Electric and Gas - 'NYSEG' - A NY electric utility whose franchise areas include the southern tier, western, central, eastern and northern NY.

New York State Power System - All facilities of the NYS Transmission System, and all those Generators located within the NYCA or outside the NYCA, some of which may from time-to-time be subject to operational control by the NYISO.

New York State Reliability Council - 'NYSRC' - An organization established by agreement among the Member Systems of the New York Power Pool (the "NYSRC Agreement").

New York State Reliability Council Agreement - NYSRC Agreement - The agreement which established the NYSRC.

New York State Research and Development Agency - 'NYSERDA'

New York State Transmission System - NYS Transmission System - The entire New York State electric transmission system, which includes: (1) the Transmission Facilities Under ISO Operational Control; (2) the Transmission Facilities Requiring ISO Notification; and (3) all remaining transmission facilities within the NYCA.

Niagara Mohawk Power Corporation - 'NMPC' - A NY electric utility whose franchise areas in the Mohawk Valley, Central, Western and Northern NY.

Nigara Mohawk Power Corporation - 'NIMO'

Non-Coincident Peak Load - See "One hour independent peak load".


Non-Firm Point-To-Point Transmission Service - Point-To-Point Transmission Service under the Tariff for which a Transmission Customer is not willing to pay Congestion. Such service is available absent Constraints under Part II of this Tariff. Non-Firm Point-To-Point Transmission Service is available on a stand-alone basis for individual one-hour periods not to exceed twenty-four (24) consecutive hours.

Nonrecallable Available Transfer Capability - 'NATC'

Non-synchronous Operating Reserve - 'NSR' - Generation which is not providing energy to the interconnected electric system but has the capability of doing so within a specified period of time ( 10 or 30 minutes).

Non-Utility Generator - 'NUG' - Any entity that owns or operates an electric generating facility that is not included in an electric utility's rate base. This term includes, but is not limited to, cogenerators and small power producers and all other non-utility electricity producers, such as exempt wholesale generators that sell electricity.

Normal Ratings - The maximum loading that electrical equipment may be subjected to continuously under nominal ambient such that no accelerated loss of equipment life would be expected. Usually two values are used throughout the year: Normal-Summer and Normal-Winter.

Normal Response Rate - 'NRR' - The rate of load change that a generating unit can achieve for normal loading purposes, expressed in MW/minute. Required for dispatch, reserve, and regulation bidding.

Normal State - The condition that the NYS Power System is in when the Transmission Facilities Under ISO Operational Control are operated within the parameters listed for Normal State in the Reliability Rules. These parameters include, but are not limited to, thermal, voltage, stability, frequency, operating reserve and Pool Control Error limitations.

North American Electric Reliability Council - 'NERC' - A voluntary industry organization made up of the ten regional reliability councils in North America and establishes and promotes standards for a reliable bulk electric system in the US and Canada.

North American Electric Reliability Organization - 'NAERO' - NERC's successor organization, will be to develop, promote, and enforce standards for a reliable North American bulk electric system. Participation in the organization will no longer be voluntary.

Northeast Power Coordinating Council - 'NPCC' - The regional organization, which includes NY, responsible for establishing reliability criteria and procedures for the region's interconnected system.

Northeast Power Coordinating Council - 'NPCC'

Notification - Informing the NYISO of all changes in status of the Transmission Facilities Requiring ISO Notification. Notification includes the Transmission Owners informing the NYISO of all changes in the status of the designated transmission facilities.

Nuclear Regulatory Commission - 'NRC' - The federal agency responsible for overseeing the safe and reliable operation of the nation's nuclear power plants.

NYISO Manuals - The instructions, rules, procedures and guidelines established by the NYISO for the operation, planning, and accounting requirements of the NY Control Area and the NY Wholesale Market.

NYISO Monitored Facilities - The collection of transmission and generation facilities contained in: 1) Transmission facilities under NYISO operational control. 2) Transmission facilities requiring NYISO notification. 3) Generators monitored by the NYISO.

NYISO Procedures - The procedures adopted by the NYISO pursuant to the NYISO Tariff and the NYISO Agreement and consistent with the Reliability Rules.

NYPA Tax-Exempt Bonds - Obligations of the New York Power Authority, the interest on which is not included in gross income under the Internal Revenue Code.

NYPA Transmission Adjustment Charge - 'NYTAC'

NYPA Transmission Adjustment Charge - 'NTAC'

NYPP's Transmission Planning Advisory Subcommittee - 'TPAS'

NYS Power System - All facilities of the NYS Transmission System, and all those Generators located within the NYCA or outside the NYCA, some of which may be from time-to-time subject to operational control by the NYISO.

NYS Transmission System - The entire New York State electric transmission system, which includes: (1) the Transmission Facilities Under ISO Operational Control; (2) the Transmission Facilities Requiring ISO Notification; and (3) all remaining transmission facilities within the NYCA.



Off-Dispatch - A Dispatchable Generator or Load that is not capable of responding to computer-issued NYISO instructions but is capable of responding to NYISO orders relayed by telephone.

Off-Peak - The hours between 11 p.m. and 7 a.m., prevailing Eastern Time, Monday through Friday, and all day Saturday and Sunday, and NERC-defined holidays, or as otherwise decided by NYISO.

On-Dispatch - A dispatchable Generator or Load that is capable of responding to computer-issued NYISO instructions.

One Hour Independent Peak Load - Is the highest integrated load over the span of a one hour period.

On-Peak - The hours between 7 a.m. and 11 p.m. inclusive, prevailing Eastern Time, Monday through Friday, except for NERC-defined holidays, or as otherwise decided by the NYISO.

Ontario Hydro - 'OH'

Open Access Same Time Information System - 'OASIS' - The information system and standards of conduct contained in Part 37 of the Commission's regulations and all additional requirements implemented by subsequent Commission orders dealing with OASIS.

Open Access Transmission Tariff - 'OATT'

Open Systems Foundation - 'OSF'

Open Systems Interconnection - 'OSI'

Operating Capacity - 'OpCap' - Capacity that is readily converted to Energy and is measured in MW.

Operating Committee - 'EC'

Operating Committee - A standing committee of the NYISO created pursuant to the ISO Agreement, which coordinates operations, develops procedures, evaluates proposed system expansions and acts as a liaison to the NYSRC.

Operating Reserves - General Capacity that is available to supply Energy, or Interruptible Load Resources that are available to Curtail Energy usage, in the event of contingency conditions which meet the requirements of the NYISO. Operating Reserves include spinning reserve, ten-minute non-synchronized reserves, and thirty-minute reserves.

Operating Study Power Flow - A Power Flow analysis that is performed at least once before each Capability Period that is used to determine each Interface Transfer Capability for the Capability Period (See Attachment M to the ISO OATT).

Operational Control - Directing the operation of the Transmission Facilities Under ISO Operational Control to maintain these facilities in a reliable state, as defined by the Reliability Rules. The NYISO shall approve operational decisions concerning these facilities, made by each Transmission Owner before the Transmission Owner implements those decisions. In accordance with ISO Procedures, the NYISO shall direct each Transmission Owner to take certain actions to restore the system to the Normal State. Operational Control includes security monitoring, adjustment of generation and transmission resources, coordination and approval of changes in transmission status for maintenance, determination of changes in transmission status for reliability, coordination with other Control Areas, voltage reductions and Load Shedding, except that each Transmission Owner continues to physically operate and maintain its facilities.

Optimal Power Flow - 'OPF' - The Power Flow analysis that is performed during the administration of the Centralized TCC Auction to determine the most efficient simultaneously feasible allocation of TCCs to Bidders (See Attachment M to the ISO OATT).

Orange and Rockland - 'O&R' - A NY electric utility whose franchise area is primarily located in the lower Hudson valley counties of Rockland and Orange.

Order Nos 888 et seq. - The Final Rule entitled Promoting Wholesale Competition Through Open Access Non-discriminatory Transmission Services by Public Utilities; Recovery of Stranded Costs by Public Utilities and Transmitting Utilities, issued by the Commission on April 24, 1996, in Docket Nos. RM95-8-000 and RM94-7-001, as modified on rehearing, or upon appeal. (See FERC Stats. & Regs. [Regs. Preambles January 1991- June 1996] . 31,036 (1996) ("Order No. 888"), on reh'g, III FERC Stats. & Regs. . 31,048 (1997) ("Order No. 888-A"), on reh'g, 81 FERC . 61,248 (1997) ("Order No. 888-B"), order on reh'g, 82 FERC . 61,046 (1998) ("Order No. 888-C") ("Order No. 888-C").

Order Nos 889 et seq. - The Final Rule entitled Open Access Same-Time Information System (formerly Real-Time Information Networks) and Standards of Conduct, issued by the Commission on April 24, 1996, in Docket No. RM95-9-000, as modified on rehearing, or upon appeal. (See FERC Stats. & Regs. [Regs. Preambles 1991-1996] . 31,035 (1996) ("Order No. 889"), on reh'g, III FERC Stats. & Regs. . 31,049 (1997) ("Order No. 889-A"), on reh'g, 81 FERC . 61,253 (1997) ("Order No. 889-B")).

Outage - A device is in outage state if it is not connected to the electrical system and not fulfilling its design function.

Outage Scheduler - 'OS'

Out-of-Merit Generation - 'OOM' - Generators producing at a different level of output than they would produce in a dispatch to meet Load which was not security constrained. Out-of-Merit Generation occurs to maintain system reliability or to provide Ancillary Services.



Part I - Tariff Sections 1A through 12 pertaining to Definitions and Common Service Provisions.

Part II - Tariff Sections 13 through 27 pertaining to Point-To-Point Transmission Service in conjunction with the applicable Common Service Provisions of Part I and appropriate Schedules and Attachments.

Part III - Tariff Sections 28 through 35 pertaining to Network Integration Transmission Service in conjunction with the applicable Common Service Provisions of Part I and appropriate Schedules and Attachments.

Part IV - Tariff Sections 36 through 37 pertaining to Retail Access Service.

Party [Agreement] - The signatories to the respective agreements.

Party or Parties [OATT] - The NYISO and the Transmission Customer receiving service under the Tariff.

PCC Operations Staff - The following are the PCC staff positions: Shift Supervisor Generation Dispatcher Transmission Dispatcher Forecasting Dispatcher Outage Coordinator

Penalty Factor - 'PF' - The incremental affect of transmission losses with a specific bus (with respect to a reference bus). Penalty Factor is the inverse of Delivery Factor.

Pennsylvania Electric Company - 'PENELEC'

Pennsylvania Power && Light Company - 'PPL'

Pennsylvania, New Jersey, Maryland Interconnection - 'PJM' - The ISO to the south of New York and encompasses a control area covering most of Pennsylvania, New Jersey, Maryland and Delaware.

Performance Index - 'PI'

Performance Index - 'PI' - An index, described in ISO Procedures, that tracks a Generator's response to AGC signals from the NYISO.

Performance Tracking System - 'PTS' - A system designed to provide quantitative comparisons of actual values versus expected and forecasted values for Generators and Loads. This system will be used by the NYISO to measure compliance with criteria associated with the provision of Regulation and Frequency Response Service.

Permissive Control Mode - A mode of Automatic Generation Control where the Member system's Satellite Control Error will not be in opposition to the Pool Control Error, even if their base points direct the dispatchable units in opposition to the Pool Control Error.

Personal Computer - 'PC'

Phase Angle Regulator - 'PAR' - A transformer that advances or retards the phase angle relationship of one circuit with respect to another to control power flow.

Phase Shifter Transformer - See "Phase Angle Regulator".

Philadelphia Electric Company - 'PE'

Picture Image - 'PCX'

Planning Committee - 'PC'

Point of Delivery - 'POD' - See "Point(s) of Withdrawal."

Point of Injection - 'POI' - The point(s) on the NYS Transmission System where Energy, Capacity and Ancillary Services will be made available to the NYISO by the Delivering Party under the ISO OATT or the ISO Services Tariff. The Point(s) of Injection shall be specified in the Service Agreement. (Same as Point of Receipt).

Point of Receipt - 'POR' - See "Point(s) of Injection."

Point of Withdrawal - 'POW' - The point(s) on the NYS Transmission System where Energy, Capacity and Ancillary Services will be made available to the Receiving Party under the ISO OATT or the ISO Services Tariff. The Point(s) of Withdrawal shall be specified in the Service Agreement. (Same as Point of Delivery).

Point-to-Point Protocol - 'PPP'

Point-to-Point Transmission Service - The reservation and transmission of Capacity and Energy on either a firm or non-firm basis from the Point(s) of Receipt to the Point(s) of Delivery under Part II of the Tariff.

Pool Control Error - 'PCE' - See "Area Control Error (ACE)"

Post Contingency - Conditions existing on a system immediately following a Contingency.

Post Unit Commitment - 'UCP'

Potomac Electric Power Company - 'PEPCO'

Power Control Center for the NYISO - 'PCC'

Power Exchange - 'PE' - A commercial entity meeting the requirements for service under the ISO OATT or the ISO Services Tariff that facilitates the purchase and/or sale of Energy, Capacity and/or Ancillary Services in a New York Wholesale Market. A PE may transact with the NYISO on its own behalf or as an agent for others.

Power Factor - 'PF' - The ratio of real power to apparent power (the product of volts and amperes, expressed in megavolt-amperes, MVA).

Power Factor Criteria - Criteria to be established by the NYISO to monitor a Load's use of Reactive Power.

Power Flow - A simulation which determines the Energy flows on the NYS Transmission System and adjacent transmission systems.

Power Purchaser - The entity that is purchasing the Capacity and Energy to be transmitted under the Tariff.

Power Technologies, Incorporated - 'PTI'

Primary Holder - A Primary Holder of each TCC is the Primary Owner of that TCC or the party that purchased that TCC at the close of the Centralized TCC Auction. With respect to each TCC, a Primary Holder must be: (1) a Customer that has purchased the TCC in the Centralized TCC Auction, and that has not resold in that same Auction; (2) a Customer that has purchased the TCC in a Direct Sale with another Customer; (3) the Primary Owner who has retained the TCC and did not sell it through the Auction; or (4) Primary Owners of the TCC that allocated the TCC to certain customers or sold it in the Secondary Market or sold through a Direct Sale to an entity other than a Customer. The NYISO settles Congestion Rents pursuant to Attachment J to the ISO OATT with the Primary of each TCC.

Primary Owner [OATT] - The Primary Owner of each TCC is the Transmission Owner or other Transmission Customer that has acquired the TCC through conversion of rights under an Existing Transmission Agreement to Grandfathered TCCs (in accordance with Attachment K) or the Transmission Owner that acquired the TCC through the NYISO's allocation of Residual TCCs (in accordance with Attachments K and M). The NYISO distributes Centralized TCC Auction revenues to Primary Owners (in accordance with Attachments K and M).

Primary Owner [Services Tariff] - The Primary Owner of each TCC is the Transmission owner or other Customer that has acquired the TCC through conversion of rights under an Existing Transmission Agreement to Grandfathered TCCs (in accordance with Attachment G) or the Transmission Owner that acquired the TCC through the NYISO's allocation of Residual TCCs (in accordance with Attachment K and M). The NYISO distributes Centralized TCC Auction revenues to Primary Owners (in accordance with Attachments K and M to the ISO OATT).

Proxy Generator Bus - A Generator bus located outside the NYCA that is selected by the NYISO to represent a typical bus in an adjacent Control Area and for which LBMP prices are calculated.

Public Data Network - 'PDN'

Public Service Commission - 'PSC' - The Public Service Commission of the State of New York or any successor agency thereto.

Public Service Electric and Gas Company - 'PS'

Public Utilities Regulatory Policy Act - 'PURPA'

Purchaser Seller Entity - 'PSE'



Qualified Installed Capacity - 'QICAP'

Quick Response Voltage Reduction - A form of "Voltage Reduction" (defined separately) accomplished by supervisory control methods and completed within 10 minutes of receiving the order.



Ramping - The term generally applied to the implementation of scheduled changes over a pre-set period of time.

Rating Authority - The Rating Authority is the member who has the authority and responsibility for maintaining the correct dynamic rating for NY Bulk Power System facilities in the NYISO PCC computer.

Reactive Power - The product of voltage and the out-of-phase component of alternating current. Reactive Power, usually measured in MVAr, is produced by capacitors (synchronous condensers) and over-excited Generators and absorbed by reactors or under-excited Generators and other inductive devices including the inductive portion of Loads.

Real Power Losses - The loss of Energy, resulting from transporting power over the NYS Transmission System, between the Point of Injection and Point of Withdrawal of that Energy.

Real-Time LBMP - The LBMPs established through the ISO Administered Real-Time Market.

Real-Time Market - The ISO Administered Market resulting from the operation of the Security Constrained Dispatch ("SCD").

Recallable Available Transmission Capability - 'RATC'

Receiving Control Area - 'RCA' - In an energy exchange between operating control areas, the control area importing the energy.


Receiving Party - The entity receiving the Capacity and Energy transmitted by the NYISO to Point(s) of Delivery.

Reduction or Reduce - The partial or complete reduction in non-Firm Transmission Service as a result of transmission Congestion (either anticipated or actual).

Reference Bus - The location on the NYS Transmission System relative to which all mathematical quantities, including Shift Factors and penalty factors relating to physical operation, will be calculated. The NYPA Marcy 345 kV transmission substation is designated as the Reference Bus.

Regional Transmission Group - 'RTG' - A voluntary organization of transmission owners, transmission users and other entities approved by the Commission to efficiently coordinate transmission planning (and expansion), operation and use on a regional (and interregional) basis.

Regional Transmission Organization - 'RTO'

Regulation - The amount of capacity responding within a given time interval to minimize the Pool Control Error.


Regulation Margin - A value expressed in megawatts which is reserved below a unit's high operating limit and above a unit's low operating limit to allow for regulation. It equals the regulating response rate in MW/minute times five minutes.

Regulation Response Rate - 'RRR' - The rate of load change that a generating unit can achieve for frequency regulation loading purposes, expressed in MW/minute. The RRR can be higher or lower than the NRR.

Relay Performance Index - 'RPI'

Reliability Assessment Program - 'RAP'

Reliability Coordination Plan - 'RCP'

Reliability Rules - Those rules, standards, procedures and protocols developed and promulgated by the NYSRC, including Local Reliability Rules, in accordance with NERC, NPCC, FERC, PSC and NRC standards, rules and regulations and other criteria and pursuant to the NYSRC Agreement.

Remote Data Access - 'RDA'

Required System Capability - Generation capability required to meet an LSE's peak Load plus Installed Capacity Reserve obligation as defined in the Reliability Rules.

Reserve Comparator - 'RC' - A NYISO EMS process that runs periodically (every 5 minutes) to verify that the reserve requirements of the NYCA are satisfied.

Reserved Capacity - The maximum amount of Capacity and Energy that the NYISO agrees to transmit for the Transmission Customer over the NYS Transmission System between the Point(s) of Receipt and the Point(s) of Delivery under Part II of the Tariff. Reserved Capacity shall be expressed in terms of whole megawatts on a sixty (60) minute interval (commencing on the clock hour) basis.

Residual Adjustment - The NYISO's collections from Loads and Transmission Customers, less its payment to generating facilities, less Congestion Rents and Excess Congestion Rents, and Primary Holders of TCCs as defined in Schedule 1.

Residual Loss Payments - Payments made by the LSEs and other Transmission Customers, and collected by the NYISO, based on Marginal Losses that exceed the payments made to the Generators to provide power to compensate for Real Power Losses.

Residual TCCs - TCCs converted from RTC, each designated from a Point of Injection to a Point of Withdrawal. Residual TCCs are: (1) estimated prior to the Centralized TCC Auction, and allocated among the Transmission Owners utilizing the Interface MW-Mile Methodology; (2) determined during the Centralized TCC Auction that are in addition to the amount estimated before the Auction, and are not allocated but are offered for sale in the Auction; and (3) determined after each Grandfathered TCC and Grandfathered Right expire and the associated capacity is released to the NYISO for sale and are not allocated but are offered for sale in the Auction. The Auction revenues and Excess Congestion Rent revenues associated with Residual TCCs that are not allocated to Transmission Owners by the NYISO shall be allocated utilizing the Interface MW-Mile Methodology (See Attachments M and N).

Residual Transmission Capacity - 'RTC' - The transmission capacity determined by the NYISO before, during and after the Centralized TCC Auction which is conceptually equal to the following: RTC = TTC - TRM - CBM - GTR - GTCC - ETCNL Where... RTC is Residual Transmission Capacity. The TCCs associated with RTC cannot be accurately determined until the Centralized TCC Auction is conducted. TTC is the Total Transfer Capability that can only be determined after the RTC is known. TRM is the Transmission Reliability Margin. CBM is the Capacity Benefit Margin. GTR is the transmission capacity associated with Grandfathered Rights. GTCC is the transmission capacity associated with Grandfathered TCCs. ETCNL is the transmission capacity associated with Existing Transmission Capacity for Native Load.

Restoration Plan - The NYISO procedures and guidelines used to restore the NY Bulk Power System following a major disturbance.

Retail Marketer - A Party that buys electricity at wholesale and sells at retail.

Rochester Gas and Electric - 'RGE' - A NY electric utility whose franchise area is primarily located in the West/Central part of NYS.



Safe Operations - Actions that avoid placing personnel and equipment in peril with regard to the safety of life and equipment damage.

Satellite Control Error - 'SCE' - A portion of the Pool Control Error that is transmitted to a Member's control center. The SCE includes any deviation from base points for that Member's Area and a percentage of the NY Control Area Regulation requirement.

SCD Base Point Signals - See "Base Point Signals".

Schedule - A statement prepared in advance detailing a plan designating time, specified values, etc., for future action or operation.

Scheduled Outage - An outage that results when a device is deliberately taken out-of-service at a preselected time.

Second Contingency Design and Operation - The planning, design and operation of a power system such that the loss of any two (2) facilities will not result in a service interruption to either native load customers or contracted firm Transmission Customers. Second Contingency Design and Operation criteria do not include the simultaneous loss of two (2) facilities, but rather consider the loss of one (1) facility and the restoration of the system to within acceptable operating parameters, prior to the loss of a second facility. These criteria apply to thermal, voltage and stability limits and are generally equal to or more stringent than NYPP, NPCC and NERC criteria.

Second Settlement - The process of: (1) identifying differences between Energy production, Energy consumption or NYS Transmission System usage scheduled in a First Settlement, and the actual production, consumption, or NYS Transmission System usage during the Dispatch Day; and (2) assigning financial responsibility for those differences to the appropriate Customers and Market Participants. Charges for Energy supplied (to replace Generation deficiencies or unscheduled consumption), and payments for Energy consumed (to absorb consumption deficiencies or excess Energy supply) or changes in transmission usage will be based on the Real-Time LBMPs.

Secondary Holder - Entities that: (1) purchase TCCs in the Secondary Market; (2) purchase TCCs in a Direct Sale from a Transmission Owner and have not been certified as a Primary Holder by the NYISO; or (3) receive an allocation of Native Load TCCs from a Transmission Owner (See Attachment M). A Transmission Customer purchasing TCCs in a Direct Sale may qualify as a Primary Holder with respect to those TCCs purchased in that Direct Sale.

Secondary Market - A market in which Primary and Secondary Holders sell TCCs by mechanisms other than through the Centralized TCC Auction or by Direct Sale. Buyers of TCCs in the Secondary Market shall neither pay nor receive Congestion Rents directly to or from the NYISO.

Secure HTTP - 'S-HTTP'

Secure Sockets Layer - 'SSL'

Security Analysis Package - 'SAP'

Security Constrained Dispatch - 'SCD' - The allocation of Load to Generators by the NYISO through the operation of a computer algorithm which continuously calculates individual Generator loading at minimum Bid cost, balancing Load and scheduled interchange with Generation while meeting all Reliability Rules and Generator performance Constraints consistent with the terms of the ISO Services Tariff.

Security Constrained Unit Commitment - See "SCUC".

Security Constrained Unit Commitment - 'SCUC' - The software process through which the NYISO, after evaluating load forecasts, price and availability Bids of Generation Resources, information on Ancillary Services Bids and Bilateral Transactions furnished to it, prepares a generation schedule for the following day through the operation of a computer algorithm which minimizes the total bid production cost of energy while meeting Reliability Rules and Generator performance constraints consistent with the terms of the NYISO Tariff and the NYPE Tariff.

Security Coordinator - An entity that provides the security assessment and Emergency operations coordination for a group of Control Areas. A Security Coordinator must not participate in the wholesale or retail merchant functions.

Self-Supply - The provision of certain Ancillary Services, or the provision of Energy to replace Marginal Losses by a Transmission Customer using either the Transmission Customer's own Generators or generation obtained from an entity other than the NYISO.

Sending Control Area - 'SCA' - In an energy exchange between operating control areas, the control area exporting energy.

Sequential Query Language - 'SQL'

Serial Line Internet Protocol - 'SLIP'

Service Agreement - The agreement, in the form of Attachment A to the ISO OATT or the ISO Services Tariff, and any amendments or supplements thereto entered into by a Transmission Customer and the NYISO for Transmission Service under the ISO OATT or between the NYISO and a Customer for services under the ISO Services Tariff or any unexecuted Service Agreement, amendments or supplements thereto, that the NYISO unilaterally files with the Commission.

Service Commencement Date [OATT] - The date the NYISO begins to provide service pursuant to the terms of an executed Service Agreement, or the date the NYISO begins to provide service in accordance with Section 15.3 or Section 29.1 under the Tariff.

Service Commencement Date [Services Tariff] - The date that the NYISO begins to provide service pursuant to the terms of a Service Agreement, or in accordance with the Tariff.

Settlement - The process of determining the charges to be paid to, or by, a Transmission Customer or a Customer to satisfy its obligations.

Shift Factor - 'SF' - A ratio, calculated by the NYISO, that compares the change in power flow through a transmission facility resulting from the incremental injection and withdrawal of power on the NYS Transmission System.

Short Term Emergency Rating - 'STE' - The maximum loading of electrical equipment which can be sustained for fifteen minutes based on nominal ambient conditions and recognizing preloading conditions. Usually two values are used during the year: STE-Summer and STE-Winter.

Short-Term Firm Point-To-Point Transmission Service - Firm Point-to-Point Service, the price of which is fixed for a short term by a Transmission Customer acquiring sufficient TCCs with the same Points of Receipt and Delivery as its Transmission Service.

Simple Network Management Protocol - 'SNMP'

Sink - See "Point of Withdrawal".

Software Verification Testing - 'SVT' - Testing of NYISO's market information system software using real time data and market participation. Exercised prior to NYISO start-up.

Solar Magnetic Distrubance - 'SMD'

Source - See "Point of Injection".

Southeastern Electric Reliability Council - 'SERC'

Southeastern New York - 'SENY' - The electrical region of NY State covered by the transmission districts of Con Edison and LI Power Authority. (Zones H, I, J and K)

Southwest Power Pool - 'SPP'

Spinning Reserve - 'SR' - Generation available on units synchronized to the bulk system and available within 30 minutes or less.

Stability - The ability of a power system to maintain a state of equilibrium during normal and abnormal system conditions or disturbances.

Standards for Planning and Operating the NYPP BPS - 'NYPP Standards'

Start-Up Bid - See "Minimum Generation and Start-Up Bid".

Static VAR Compensator - 'SVC' - A Transmission Facility device used to automatically supply or absorb reactive power to maintain a pre-set voltage level.

Steady State Stability - The ability of a power system to maintain a state of equilibrium during normal and abnormal system conditions or disturbances.

Storm Watch - Actual or anticipated severe weather conditions under which region-specific portions of the NYS Transmission System are operated in a more conservative manner by reducing transmission transfer limits.

Strandable Costs - Prudent and verifiable expenditures and commitments made pursuant to a Transmission Owner's legal obligations that are currently recovered in the Transmission Owner's retail or wholesale rate that could become unrecoverable as a result of a restructuring of the electric utility industry and/or electricity market, or as a result of retail-turned-wholesale customers, or customers switching generation or transmission service suppliers.

Stranded Investment Recovery Charge - 'SIRC' - A charge established by a Transmission Owner to recover Strandable Costs.

Sub-Zone - The geographic area within a load zone which is served by the same Transmission Owner so that all loads within that area are billed the same Transmission Service Charge (TSC) Rate.

Supervisory Control and Data Acquisition - 'SCADA'

Supplemental Resource Evaluation - 'SRE' - A determination of the least cost selection of additional generators, which are to be committed, to meet changed conditions that may cause the original system dispatch to be inadequate to meet Load and/or reliability requirements.

Supplier - A Party that is supplying the Capacity, Energy and/or associated Ancillary Services to be made available under the ISO OATT or the ISO Services Tariff, including Generators and Demand Side Resources that satisfy all applicable ISO requirements.

Synchronous Condenser - A synchronous machine which operates to supply or absorb reactive power for voltage control purposes.

System Impact Study - An assessment by the NYISO of (i) the adequacy of the NYS Transmission System to accommodate a request to build facilities in order to create incremental transfer capability, resulting in incremental TCCs, in connection with a request for either Firm Point-To-Point Transmission Service or Network Integration Transmission Service; and (ii) the additional costs to be incurred in order to provide the incremental transfer capability.

System Independent Data Format - 'SIDF'

System Operation Procedures Manual - 'SOP'

System Protection Advisory Subcommittee - 'SOAS'



Tariff - See "Part I", "Part II", "Part III", and "Part IV".

Task Force on System Studies - 'TFSS'

TCC Market Clearing Price - The market clearing price for TCCs awarded in the centralized TCC auction is the price at which all TCCs between specific POIs and POWs in a specific stage of the auction are sold for the duration of the centralized TCC auction period.

The ISO Open Access Transmission Tariff - 'ISO OATT'

The Public Service Commission of the State of New York - 'NYSPSC'

Third Party Sale - Any sale for resale in interstate commerce to a Power Purchaser that is not designated as part of Network Load under the Network Integration Transmission Service.

Third Party Transmission Wheeling Agreements - A Transmission Wheeling Agreement, as amended, between Transmission Owner or between a Transmission Owner and an entity that is not a Transmission Owner associated with the purchase (or sale) of Energy, Capacity, and/or Ancillary Services for the benefit of an entity that is not a Transmission Owner. These agreements are listed in Table 1 of Attachment L to the ISO OATT.

Third Party TWA's - See "Third Party Transmission Wheeling Agreements"

To move on - 'FIDO' - To move on some more.


TO's Monthly Transmission System Peak - Transmission Owner's Monthly Transmission System Peak - The maximum hourly firm usage as measured in megawatts (MW) of the Transmission Owner's transmission system in a calendar month.

Total Transfer Capability - 'TTC' - The amount of electric power that can be transferred over the interconnected transmission network in a reliable manner.

Total Transmission Capability - 'TTC' - The amount of electric power that can be transferred over the interconnected transmission network in a reliable manner.

Transfer Capability - The measure of the ability of interconnected electrical systems to reliably move or transfer power from one area to another over all transmission facilities (or paths) between those areas under specified system conditions.

Transformer - A static electric device consisting of a winding, or two or more coupled windings, with or without a magnetic core, for introducing mutual coupling between electric circuits.

Transient Stability - The ability of a power system to maintain synchronism between its parts when subjected to a fault of specified severity and to regain a state of equilibrium.

Transmission and Distribution Facility - 'TDF'

Transmission Congestion Contract - 'TCC' - The right to collect or obligation to pay Congestion Rents associated with a single MW of transmission between a specified POI and POW. TCCs are financial instruments that enable Energy buyers and sellers to hedge fluctuations in the price of transmission.

Transmission Congestion Contracts Auction - See "Centralized Transmission Congestion Contracts Auction".

Transmission Customer [OATT] - Any Eligible Customer (or its designated agent) that (i) executes a Service Agreement, or (ii) requests in writing that the NYISO file with the Commission a proposed unexecuted Service Agreement to receive Transmission Service under Part II, III and/or IV of the Tariff.

Transmission Customer [Services Tariff] - Any entity (or its designated agent) that receives Transmission Service pursuant to a Service Agreement and the terms of the ISO OATT.

Transmission Distribution Provider - 'TDP'

Transmission District - 'TD' - A geographical area that is comprised of one or more subzones associated with the same Transmission Provider.

Transmission District - The geographic area served by the Investor-Owned Transmission Owners and LIPA, as well as the customers directly interconnected with the transmission facilities of the Power Authority of the State of New York.

Transmission Facilities Requiring ISO Notification - The transmission facilities of the Transmission Owners listed in Appendix A-2 of the ISO/TO Agreement, "Listing of Transmission Facilities Requiring ISO Notification," whose status of operation must be provided to the NYISO by the Transmission Owners (for the purposes stated in the ISO Tariffs, and in accordance with, the ISO Tariffs and ISO/TO Agreement) prior to the Transmission Owners making operational changes to the state of these facilities. This listing may be amended from time-to-time as specified in the ISO/TO Agreement.

Transmission Facilities Under ISO Operation Control - The transmission facilities of the Transmission Owners listed in Appendix A-1 of the ISO/TO Agreement, "Listing of Transmission Facilities Under ISO Operational Control"), that are subject to the Operational Control of the NYISO. This listing may be amended from time-to-time as specified in the ISO/TO Agreement.

Transmission Facility Agreement - The agreements listed in Attachment L, Table 2 of the ISO OATT governing the use of specific or designated transmission facilities charges all, or a portion, of the costs to install, own, operate, or maintain said transmission facilities, to the customer under the agreement. These agreements may or may not have provisions to provide Transmission Service utilizing said transmission facilities.

Transmission Fund - The mechanism used under the current NYPP Agreement to compensate the Member Systems for providing Transmission Service for economy Energy Transactions over their transmission systems. Each Member System is allocated a share of the economy Energy savings in dollars assigned to the fund that is based on the ratio of their investment in transmission facilities to the sum of investments in transmission and generation facilities.

Transmission Loading Relief - 'TLR'

Transmission Owner - 'TO' - A public utility or authority that owns transmission facilities and provides Transmission Service under the Tariff

Transmission Owner [Agreement] - An entity that owns, controls and operates facilities in New York State used for the transmission of Energy in interstate commerce. A Transmission Owner must own, individually or jointly, at least 100 circuit miles of 115 kV or above in New York State and has become a signatory to the ISO/TO Agreement.

Transmission Owner [OATT] - The public utility or authority (or its designated agent) that owns facilities used for the transmission of Energy in interstate commerce and provides Transmission Service under the Tariff.

Transmission Plan - A plan developed by the NYISO staff with Transmission Owner's support that is a compilation of transmission projects proposed by the Transmission Owners and others, that are found to meet all applicable criteria.

Transmission Provider - 'TP' - Same as a TO

Transmission Reliability Margin - 'TRM' - The amount of TTC reserved by the NYISO to ensure the interconnected transmission network is secure under a reasonable range of uncertainties in system conditions.

Transmission Service - Point-To-Point Network Integration or Retail Access Transmission Service provided under the ISO OATT.

Transmission Service Charge - 'TSC' - A charge under the ISO OATT designed to ensure recovery of the embedded cost of a Transmission Owner's transmission system.

Transmission Service District - 'TSD'

Transmission Services Cost Allocation Task Force - 'TSCATF'

Transmission System - The facilities operated by the NYISO that are used to provide Transmission Services under the ISO OATT.

Transmission Usage Charge - 'TUC' - Payments made by the Transmission Customer to cover the cost of Marginal Losses and, during periods of time when the transmission system is constrained, the marginal cost of Congestion. The TUC is equal to the product of: (1) the LBMP at the POW minus the LBMP at the POI (in $/MWh); and (2) the scheduled or delivered Energy (in MWh).

Transmission Wheeling Agreement - 'TWA' - The agreements listed in Tables 1A and 1B of Attachment L to the ISO OATT governing the use of specific or designated transmission facilities that are owned, controlled or operated by an entity for the transmission of Energy in interstate commerce.

Transport Control Protocol and Internet Protocol - 'TCP/IP'



U.S. Generators Inc. - 'USGen'

Unforced Capacity - 'UCAP'

Unit Commitment - 'UC'

Unit Commitment History - 'UCH'

Unit Control Error - 'UCE'

Unit Participation Factor - 'UPF' - The portion of a Control Area's control error for which particular unit on control is assigned to regulate.

United Gas Improvement - 'UGI'

Universal Resource Locator - 'URL'

Uplift Charge - All actual Load, including wheels exiting the NY Control Area, pay a non-bypassable charge that includes: minimum generation payments (which are above market revenue) to units that are committed by the NYISO. any insufficiencies in Congestion Rents due to changes in transmission capacity during the day. the net of transactions made by the NYISO with external transmission systems in Emergency situations. (Not applied to wheel-out and wheel-through transactions).

Upper Operating Limit - 'UOL' - Upper Operating Limit of a generator under normal operating conditions and less than the full operating range of the bid curve

Upstate New York - 'UPNY' - The NYCA north of the Consolidated Edison transmission district.

Utility Communications Architecture - 'UCAtm'



VACAR-ECAR-MAAC - 'VEM'

Vermont Electric Power Company - 'VELCO'

Virginia Power - 'VP'

Virginia-Carolinas Systems - 'VACAR'

Volt Ampere Reactive - 'VAR' - A measurement of reactive power

Voltage Payment Factor - 'VPF' - A factor which accounts for the relative impact of a Generation Resource on NY Bulk Power System voltages.

Voltage Reduction - A means of achieving load reduction by reducing customer supply voltage, usually by 3, 5, or 8 percent. If ordered to go into Voltage Reduction, Transmission Provider dispatchers immediately comply with that order.

Volts - 'V'

Voting Share - The method used in the ISO Agreement to allocate voting rights among the members of the Management Committee. The formula for calculating a Party's Voting Share is provided in the ISO Agreement.



Watts - 'W'

Western Systems Coordinating Council - 'WSCC'

Wheels Through - Transmission Service, originating in another Control Area, that is wheeled through the NYCA to another Control Area.

Wholesale Market - The sum of purchases and sales of Energy and Capacity for resale along with Ancillary Services needed to maintain reliability and power quality at the transmission level coordinated together through the NYISO and Power Exchanges. A party who purchases Energy, Capacity or Ancillary Services in the Wholesale Market to serve its own Load is considered to be a participant in the Wholesale Market.

Wholesale Marketer - A Party that buys and sells electricity at wholesale.

Winter Peaking TD - A TD whose maximum peak load over the last two Capability Periods occurred during the winter period.



Zonal Control Error - 'ZCE' - The differences between scheduled net interchange and actual net interchange for a zone within the NY Control Area.

Zonal Net Interchange - 'ZNI'

Zone - A defined portion of the NY Control Area that encompasses a set of load and generation buses. Each Zone has an associated zonal price that is calculated as a weighted average price based on generator LBMPs and generator Bus Load Distribution Factors. A "zone" outside the NY Control Area is referred to as an External Zone. Currently, New York State is divided into eleven zones, corresponding to ten major transmission interfaces that can become congested.