Glossary of terms and acronyms
The definitions and acronyms included in this glossary originate from the Business Practice Manual for Definitions and Acronyms.  The symbols [T] and [M] indicate the definition was obtained from the ISO Tariff Appendix A, Master Definitions Supplement. The symbol [M] definitions were modified slightly for consistency with the business practice manuals and to improve definition accuracy.
Please refer to the Business Practice Manual for Definitions and Acronyms for the most up to date list of terms.
Updated 11/13/2015
Filter by letter of the alphabet, acronym or term name.
AAccepted Bid
A Submitted Bid that has passed Bid content verification process as described in tariff section of the BPM for Market Instruments.
AAIMAccess and Identity Management
AAccess Charge
A charge paid by all Utility Distribution Companies, Small Utility Distribution Companies, and MSS Operators with Gross Load in a PTO Service Territory, as set forth in Article II. The Access Charge includes the Regional Access Charge and the Local Access Charge. The Access Charge will recover the Participating TO’s Transmission Revenue Requirement in accordance with Appendix F, Schedule 3.[T]
AAPAccounts Payable
Money the California ISO owes to a Business Associate.
AARAccounts Receivable
Money a Business Associate owes to the California ISO.
AActual Settlement Quality Meter Data
Settlement Quality Meter Data gathered, edited, validated, and submitted by the Scheduling Coordinators on behalf of Scheduling Coordinator Metered Entities. [T]
AAdjusted Load Metric
A Load Serving Entity’s Load Metric minus the megawatts of Load served using Existing Transmission Contracts, Converted Rights, and Transmission Ownership Rights. [T]
AAdjusted RMR Invoice
The monthly invoice issued by the RMR Owner to the California ISO for adjustments made to the Revised Estimated RMR Invoice pursuant to the RMR Contract reflecting actual data for the billing month. [T]
AAdjusted Verified CRR Source Quantity
The MW amount eligible for nomination by an LSE or Qualified OBAALSE in a verified tier of the CRR Allocation process, determined by reducing a Verified CRR Source Quantity to account for circumstances where the ownership or contract right to a generating resource is effective only for a portion of a particular season or month for which CRRs are being nominated. [T]
AAdministrative Price
The price set by the CAISO in place of a Locational Marginal Price when, by reason of a System Emergency, the CA ISO determines that it no longer has the ability to maintain reliable operation of the CAISO Controlled Grid relying solely on the economic Dispatch of Genera tion. This price will remain in effect until the CAISO considers that the Sy stem Emergency has been contained and corrected. [T]
AAdverse System Impact
The negative effects due to technical or operational limits on conductors or equipment being exceeded that may compromise the safety and reliability of the electric system. [T]
AAffected System
An electric system other than the CAIS O Controlled Grid that may be affected by the proposed interconnection, includi ng the Participating TOs’ electric systems that are not part of the CAISO Controlled Grid. [T]
AAffected System
The entity that operates an Affected System. [T]
With respect to a corporation, partnership or other entity, each such other corporation, partnership or other entity that directly, or indirectly through one or more intermediaries, controls, or is controlled by, or is under common control with such corporation, partnership or other entity. [T]
AAggregate Credit Limit
The sum of a Market Participant’s or CRR Holder’s Unsecured Credit Limit and its Financial Security Amount, as provided for in tariff section 12. [T]
AAggregate Generating Resource
A Physical Scheduling Plant or System Unit.
AAggregated Participating Load
An aggregation at one or more Participating Load Locations, created by the California ISO in consultation with the relevant Participating Load, for the purposes of enabling participation of the Participating Load in the California ISO Markets like Generation by submitting Supply Bids when offering Curtailable Demand and as non-Participating Load by submitting Demand Bids to consume in the Day-Ahead Market only. [T]
AAPLAggregated Pricing Location
AAPNode/APNAggregated Pricing Node (Aggregated Pnode)
A Load Aggregation Point, Trading Hub or any group of Pricing Nodes as defined by the California ISO. [T]
AAggregated Unit
A group of two or more Generating Units, each individually capable of producing Energy and operating in parallel with the electric grid in the ISO Balancing Authority Area, which are aggregated for scheduling and Settlement purposes and operated as if they were a single Generating Unit. An Aggregated Unit must first be approved by the ISO and may represent a Physical Scheduling Plant or collection of other Generating Units, which need to be combined for operational purposes due to common metering, electrical connection arrangement, interrelated operating characteristics, or other physical factors or constraints.
AAWEAlert, Warning or Emergency Notice
A California ISO operations communication issued to Market Participants and the public, under circumstances and in a form specified in California ISO Operating Procedures, when the operating requirements of the California ISO Controlled Grid are marginal because of Demand exceeding forecast, loss of major Generation sources, or loss of transmission capacity that has curtailed imports into the California ISO Balancing Authority Area, or if insufficient Bids for the Supply of Energy and Ancillary Services have been submitted in the RTM for the California ISO Balancing Authority Area. [T]
AACAlternating Current
AADRAlternative Dispute Resolution
AAmended QF Contract
A legacy power purchase agreement, as defined in the settlement approved by the CPUC in Decision D. 10-12-035 (December16, 2010), as modified in Decision D.11-07-010 (July 15, 2011), that became effective on or prior to December 20, 1995 or, in the case of a Participating Generator employing landfill gas technology, onor prior to December 31, 1996, that has been amended to include terms that conform with a Legacy PPA Amendment or a Legacy PPAC1 Amendment, as defined by said settlement, but also in a manner that (a) requires compliance with the ISO Tariff; (b) does not extend the term of the agreement or providefor an increase in the generating capacity ofthe resource; and (c) does not change the electrical characteristics of the resource. [T]
AAmended QF Contract
A Legacy PPA, as defined in the settl ement approved by the CPUC in Decision D. 10-12-035 (December 16, 2010), as modified in Decision D.11-07- 010 (July 15, 2011), that became effective on or prior to December 20, 1995 or, in the case of a Partici pating Generator employing landfill gas technology, on or prior to December 31, 1996, that has been amended to include terms that conform with a Legacy PPA Amendment or a Legacy PPA C1 Amendment, as defined by said settlement, but also in a manner that (a) requires compliance with the CAISO Tariff; (b) does not extend the term of the agreement or provide for an increase in the generating capaci ty of the resource; and (c) does not change the electrical characteristics of the resource. [T]
AAncillary Service Award or AS Award
The notification by the California ISO indicating that a Bid to supply an Ancillary Service has been selected to provide such service in the DAM or RTM. [T]
AAncillary Service Bid Cost or AS Bid Cost
An amount equal to the product of the AS Award from each accepted AS Bid, reduced by any applicable No Pay capacity, and the relevant AS Bid price. [T]
AAncillary Service Bid or AS Bid
The Bid component that indicates the quantity in MW and a price in dollars per MW for a specific Ancillary Service, including Regulation Up, Regulation Down, Spinning Reserve and Non-Spinning Reserve, that a Scheduling Coordinator is offering to supply in a California ISO Market from a Generating Unit or System Resource, and only for Non-Spinning Reserve from the Load of a Participating Load or Proxy Demand Resource. [T]
AASMPAncillary Service Marginal Price
The marginal cost of providing an Ancillary Serviceas further provided in tariff section 27.1.2. [T]
AAncillary Service Obligation or AS Obligation
A Scheduling Coordinator’s hourly obligation for Regulation Down, Regulation Up, Spinning Reserves, and Non-Spinning Reserves calculated pursuant to tariff section,,, and, respectively. [T]
AAncillary Service Provider
A Participating Generator, System Resource operator,  Participating Load, or Proxy Demand Resource that is certified to provide an Ancillary Service. [T]
AAncillary Service Region or AS Region
The System Region, the Expanded System Region, or any Sub-Region identified by the California ISO for procurement of Ancillary Services. [T]
AAncillary Service Regional Limit
A maximum or a minimum, or both a maximum and a minimum, amount of (or boundary of) Ancillary Services to be obtained within an AS Region.  Limits can be expressed as either megawatt amounts or percentages. [T]
AAncillary Service Schedule or AS Schedule

​The notification by the CAISO indicating that a Submission to Self-Provide an Ancillary Service has been selected to provide such service in the DAM or RTM. [T]

AASAncillary Services
Regulation, Spinning Reserve, Non-Spinning Reserve, Voltage Support and Black Start together with such other interconnected operation services as the California ISO may develop in cooperation with Market Participants to support the transmission of Energy from Generation resources to Loads while maintaining reliable operation of the California ISO Controlled Grid in accordance with WECC standards and Good Utility Practice. [T]
AAnnual Interregional Coordination Meeting
Shall have the meaning set forth in Section 24.18.2. [T]
Annual Interregional Information
Shall have the meaning set forth in Section 24.18.1. [T]
AAnnual Peak Demand Forecast
A Demand Forecast of the highest Hourly Demand in a calendar year, in MW. [T]
AApplicable Reliability Criteria
The Reliability Standards and reliability criteria established by NERC and WECC and Local Reliability Criteria, as amended from time to time, including any requirements of the NRC. [T]
AApproved Load Profile
Local Regulatory Authority approved Load profiles applied to cumulative End-Use Meter Data in order to allocate consumption of Energy to Settlement Periods. [T]
AApproved Maintenance Outage
A Maintenance Outage, which has been approved by the California ISO through the California ISO Outage Coordination Office. [T]
AApproved Project
The person or entity designated under the CAISO Tariff to construct, finance and own transmission additions or upgrades. [T]
AApproved Project Sponsor Agreement
An agreement between an Approved Project Sponsor and the CAISO establishing the terms and conditions under which the Approved Project Sponsor will complete the siting and construction of the transmission facilities that the Approved Project Sponsor was selected to construct and own under Section 24. Among other terms, the Agreement shall include any binding cost control measures, including cost caps, that the Approved Project Sponsor specified in its proposal.
AApproved Project Sponsor Tariff
A tariff specifying the rates and charges of an Approved Project Sponsor that is not a Participating TO to recover the costs of transmission facilities that are not yet in operation but have been approved under Section 24 and assigned to the Approved Project Sponsor, and associated terms and conditions.
AACEArea Control Error
The sum of the instantaneous difference between the actual net Interchange and the scheduled net Interchange between the California ISO Balancing Authority Area and all interconnected Balancing Authority Areas, taking into account the effects of the California ISO Balancing Authority Area’s frequency bias, correction of meter error, and time error correction obligations. [T]
AArea Delivery Constraint
A transmission system operating limit, t hat would constrain the deliverability of a substantial number of generators if the ISO were to assign full capacity or partial capacity deliverability status to additional generating facilities in one or more specified geographic or electrical areas of the ISO Controlled Grid in a total amount that is greater than the TP Deliverability for those areas. May also be a transmission system operating lim it that constrains a quantity of generation in a local area of the grid that is larger than the generation amount identified in the applicable Transmission Planning Process portfolio for the entire portfolio area May also be a transmission system operating limit that constrains all or most of the same generation already constrained by a previously identified Area De liverability Constraint. [T]
AADNUArea Delivery Network Upgrade
A transmission upgrade or addition identified by the ISO to relieve an Area Deliverability Constraint. [T]
An induction, doubly-fed, or electronic power generating unit(s) that produces 60 Hz (nominal) alternating current. [T]
AAttaining Balancing Authority Area
The Balancing Authority Area where the output of a Pseudo-Tie generating unit is fully included for purposes of calcul ation of Area Control Error and meeting Balancing Authority Area load responsibilities. [T]
AACHAutomated Clearing House
An electronic network for financial transactions in the United States. [T]
1 - 50Next