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Glossary - R

For your convenience, this page contains an alphabetically organized list of terms, definitions and common acronyms used in the electric utility industry.

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Term/Acronym Definition
RAP Remedial Action Plan
RDF Reserve Discount Factor
REC Renewable Energy Credit
REG-DOWN Regulation Down
REG-UP Regulation Up
REP Retail Electric Provider
RID Resource ID
RIDR Representative IDR
RMR Reliability Must-Run
RMS Retail Market Subcommittee
ROS Reliability and Operations Subcommittee
RPG Regional Planning Group
RPP Renewable Production Potential
RPS Renewable Portfolio Standard
RRS Responsive Reserve

RSASM

Reconfiguration Supplemental Ancillary Services Market

RTEP Real-Time Energy Price
RTM Real-Time Market
RUC Reliability Unit Commitment
Rating

Conductor/Transformer 2-Hour Rating
The two-hour MVA rating of the conductor or transformer only, excluding substation terminal equipment in series with a conductor or transformer, at the applicable ambient temperature. The conductor or transformer can operate at this rating for two hours without violation of National Electrical Safety Code (NESC) clearances or equipment failure.

Emergency Rating
The two-hour MVA rating of a Transmission Element, including substation terminal equipment in series with a conductor or transformer, at the applicable ambient temperature. The Transmission Element can operate at this rating for two hours without violation of NESC clearances or equipment failure.

15-Minute Rating
The 15-minute MVA rating of a Transmission Element, including substation terminal equipment in series with a conductor or transformer, at the applicable ambient temperature and with a step increase from a prior loading up to 90% of the Normal Rating. The Transmission Element can operate at this rating for 15 minutes, assuming its pre-contingency loading up to 90% of the Normal Rating limit at the applicable ambient temperature, without violation of NESC clearances or equipment failure. This rating takes advantage of the time delay associated with heating of a conductor or transformer following a sudden increase in current.

Normal Rating
The continuous MVA rating of a Transmission Element, including substation terminal equipment in series with a conductor or transformer, at the applicable ambient temperature. The Transmission Element can operate at this rating indefinitely without damage, or violation of NESC clearances.

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, overexcited generators and other capacitive devices and is absorbed by reactors, under-excited generators and other inductive devices.
Real-Time The current instant in time.
Real-Time Market (RTM) Energy Bid A proposal to buy energy in the RTM at a monotonically non-increasing price with increasing quantity.
Real-Time Market (RTM) Final Statement The RTM Settlement Statement issued at the end of the 55th day following the Operating Day, as described in Section 9.5.5, RTM Final Statement.
Real-Time Market (RTM) Initial Statement See Settlement Statement
Real-Time Market (RTM) Resettlement Statement See Settlement Statement
Real-Time Market (RTM) True-Up Statement See Settlement Statement
Real-Time Off-Line Reserve Price Adder A Real-Time price adder that captures the value of the opportunity costs of Off-Line reserves based on the defined ORDC as detailed in Section 6.7.4, Real-Time Ancillary Service Imbalance Payment or Charge.

Real-Time On-Line Reliability Deployment Price

A Real-Time price for each 15-minute Settlement Interval reflecting the impact of reliability deployments on energy prices that is calculated from the Real-Time On-Line Reliability Deployment Price Adder.

Real-Time On-Line Reliability Deployment Price Adder

A Real-Time price adder that captures the impact of reliability deployments on energy prices for each Security-Constrained Economic Dispatch (SCED) process as detailed in Section 6.5.7.3.1, Determination of Real-Time On-Line Reliability Deployment Price Adder, and Section 6.7.4, Real-Time Ancillary Service Imbalance Payment or Charge.

Real-Time On-Line Reserve Price Adder A Real-Time price adder that captures the value of the opportunity costs of On-Line reserves based on the defined ORDC as detailed in Section 6.7.4.
Real-Time Reserve Price for Off-Line Reserves A Real-Time price calculated for Off-Line reserves for each 15-minute Settlement Interval using the data and formulas as detailed in Section 6.7.4.
Real-Time Reserve Price for On-Line Reserves A Real-Time price calculated for On-Line reserves for each 15-minute Settlement Interval using the data and formulas as detailed in Section 6.7.4.
Redacted Network Operations Model A version of the Network Operations Model, redacted to exclude Private Use Network Load data and the following defined Resource Parameters as applicable:
  • Normal Ramp Rate curve;
  • Emergency Ramp Rate curve;
  • Minimum On-Line time;
  • Minimum Off-Line time;
  • Hot start time;
  • Intermediate start time;
  • Cold start time;
  • Maximum weekly starts;
  • Maximum On-Line time;
  • Maximum daily starts;
  • Maximum weekly energy;
  • Hot-to-intermediate time;
  • Intermediate-to-cold time;
  • Minimum interruption time;
  • Minimum restoration time;
  • Maximum weekly deployments;
  • Maximum interruption time;
  • Maximum daily deployments;
  • Minimum notice time; and
  • Maximum deployment time.
Regional Planning Group (RPG) Project Review

The evaluation of a proposed transmission project pursuant to the process described in Section 3.11.4, Regional Planning Group Project Review Process.

Regulation Service

An Ancillary Service that consists of either Regulation Down Service (Reg-Down) or Regulation Up Service (Reg-Up)

Fast Responding Regulation Service (FRRS)

A subset of Regulation Service that consists of either Fast Responding Regulation Down Service (FRRS-Down) or Fast Responding Regulation Up Service (FRRS-Up). Except where otherwise specified, all requirements that apply to Regulation Service also apply to FRRS.

Regulation Down Service (Reg-Down)

An Ancillary Service that provides capacity that can respond to signals from ERCOT within five seconds to respond to changes in system frequency. Such capacity is the amount available below any Base Point but above the LSL of a Generation Resource and may be called on to change output as necessary throughout the range of capacity available to maintain proper system frequency. A Load Resource providing Reg-Down must be able to increase and decrease Load as deployed within its Ancillary Service Schedule for Reg-Down below the Load Resource’s MPC limit.

Fast Responding Regulation Down Service (FRRS-Down)

A subset of Reg-Down in which the participating Resource provides Reg-Down capacity to ERCOT within 60 cycles of either its receipt of an ERCOT Dispatch Instruction or its detection of a trigger frequency independent of an ERCOT Dispatch Instruction. Except where otherwise specified, all requirements that apply to Reg-Down also apply to FRRS-Down.

Regulation Up Service (Reg-Up)

An Ancillary Service that provides capacity that can respond to signals from ERCOT within five seconds to respond to changes in system frequency. Such capacity is the amount available above any Base Point but below the HSL of a Generation Resource and may be called on to change output as necessary throughout the range of capacity available to maintain proper system frequency. A Load Resource providing Reg-Up must be able to increase and decrease Load as deployed within its Ancillary Service Schedule for Reg-Up above the Load Resource’s LPC limit.

Fast Responding Regulation Up Service (FRRS-Up)

A subset of Reg-Up in which the participating Resource provides Reg-Up capacity to ERCOT within 60 cycles of either its receipt of an ERCOT Dispatch Instruction or its detection of a trigger frequency independent of an ERCOT Dispatch Instruction. Except where otherwise specified, all requirements that apply to Reg-Up also apply to FRRS-Up.

Regulation Up Service (Reg-Up) See Regulation Service

Reliability Monitor

An Entity selected by the Public Utility Commission of Texas (PUCT) to monitor compliance with all state reliability-related laws, rules, and ERCOT procedures, including Protocols, processes, and any other operating standards applicable to the ERCOT Region.

Reliability Must Run (RMR) Service An Ancillary Service provided from an RMR Unit under an Agreement with ERCOT.

Reliability Must Run (RMR) Unit

A Generation Resource operated under the terms of an Agreement with ERCOT that would not otherwise be operated except that it is necessary to provide voltage support, stability or management of localized transmission constraints under Credible Single Contingency criteria where market solutions do not exist.

Reliability Unit Commitment (RUC) A process to ensure that there is adequate Resource capacity and Ancillary Service capacity committed in the proper locations to serve ERCOT forecasted Load.
Reliability Unit Commitment (RUC) Buy-Back Hour An Operating Hour for which a QSE with a Resource that is not an RMR Unit that has been committed to come On-Line by a RUC process or Verbal Dispatch Instruction (VDI) may choose, at its sole discretion, to self-commit that Resource in lieu of the RUC instruction or VDI.
Reliability Unit Commitment (RUC) Cancellation An ERCOT instruction, prior to breaker close, to cancel a previously issued RUC instruction.
Reliability Unit Commitment (RUC) Study Period As defined under Section 5.1, Introduction.
Reliability Unit Commitment (RUC)-Committed Hour An Operating Hour for which a RUC has committed a Resource to be On-Line and the QSE has not designated a RUC Buy-Back Hour.
Reliability Unit Commitment (RUC)-Committed Interval A Settlement Interval for which there is a RUC instruction to commit a Resource.
Remedial Action Plan (RAP) A set of pre-defined actions to execute post-contingency to address voltage issues or in order to reduce loading on one or more given, monitored Transmission Facilities to below their Emergency Rating within 15 minutes. RAPs are sufficiently dependable to assume they can be executed without loss of reliability to the interconnected network, with restoration of normal operating conditions and below Normal Rating within two hours as defined in the Network Operations Model. RAPs may be relied upon in allowing additional use of the transmission system in SCED. RAPs may not include Load shedding.
Renewable Energy Credit (REC) A tradable instrument that represents all of the renewable attributes associated with one MWh of production from a certified renewable generator.
Renewable Energy Credit (REC) Account An account maintained by ERCOT for the purpose of tracking the production, sale, transfer, purchase, and retirement of RECs or Compliance Premiums by a REC Account Holder.
Renewable Energy Credit (REC) Account Holder An Entity registered with ERCOT to participate in the REC Trading Program.
Renewable Energy Credit (REC) Trading Program The Renewable Energy Credit Trading program, as described in Section 14, State of Texas Renewable Energy Credit Trading Program, and P.U.C. SUBST. R. 25.173, Goal for Renewable Energy.
Renewable Portfolio Standard (RPS) The amount of capacity required to meet the requirements of Public Utility Regulatory Act (PURA), TEX. UTIL. CODE ANN. § 39.904 (Vernon 1998 & Supp. 2007) and P.U.C. SUBST. R. 25.173(h).

Renewable Production Potential (RPP)

The maximum generation in MWh per interval from an Intermittent Renewable Resource (IRR) that could be generated from all available units of that Resource.  The RPP depends on the renewable energy that can be generated from the available units (wind, solar radiation, or run-of-river water supply), current environmental conditions and the energy conversion characteristics of each unit.

Repowered Facility An existing facility that has been modernized or upgraded to use renewable energy technology to produce electricity consistent with P.U.C. SUBST. R. 25.173, Goal for Renewable Energy.
Reserve Discount Factor (RDF) A representation of the average amount of system-wide capability that, for whatever reason, is historically undeliverable during periods of high system demand. The RDF will be verified by ERCOT and then approved by the Reliability and Operations Subcommittee (ROS).
Resettlement Statement See Settlement Statement
Resource

The term is used to refer to both a Generation Resource and a Load Resource. The term "Resource" used by itself in these Protocols does not include a Non-Modeled Generator or an ERS Resource.

Resource Category The generation technology category designated for a Generation Resource in its Resource Registration documentation.

Resource Commissioning Date

The date on which ERCOT declares that a Resource has completed all qualification testing administered by ERCOT as part of the Resource Interconnection process so that a Resource is approved for participation in ERCOT market operations.

Resource Connectivity Node

The Electrical Bus to which the terminal of a Resource is connected.

Resource Entity An Entity that owns or controls an All-Inclusive Resource and is registered with ERCOT as a Resource Entity.
Resource ID (RID) A unique identifier assigned to each Resource used in the registration and Settlements systems managed by ERCOT.
Resource Node Either a logical construct that creates a virtual pricing point required to model a Combined-Cycle Configuration or an Electrical Bus defined in the Network Operations Model, at which a Generation Resource's Settlement Point Price or WSL's Settlement Point Price is calculated and used in Settlement. All Resource Nodes shall be identified in accordance with the document titled "Procedure for Identifying Resource Nodes," which shall be approved by the appropriate TAC subcommittee and posted to the MIS Public Area. For a Generation Resource that is connected to the ERCOT Transmission Grid only by one or more radial transmission lines that all originate at the Generation Resource and terminate in a single substation switchyard, the Resource Node is an Electrical Bus in that substation. For all other Generation Resources, the Resource Node is the Generation Resource's side of the Electrical Bus at which the Generation Resource is connected to the ERCOT Transmission Grid.
Resource Parameters Resource-specific parameters required for use in ERCOT business processes. This is a subset of Resource Registration data that can be changed in the MIS in Real-Time.
Resource Registration Provision of Resource information to register All-Inclusive Resources.
Resource Status The operational state of a Resource as provided in Section 3.9, Current Operating Plan (COP).
Responsive Reserve (RRS) An Ancillary Service that provides operating reserves that is intended to:
  1. Arrest frequency decay within the first few seconds of a significant frequency deviation on the ERCOT Transmission Grid using Primary Frequency Response and interruptible Load;
  2. After the first few seconds of a significant frequency deviation, help restore frequency to its scheduled value to return the system to normal;
  3. Provide energy or continued Load interruption during the implementation of the EEA; and
  4. Provide backup regulation.
Retail Business Day See Business Day
Retail Business Hour Any hour within a Retail Business Day.
Retail Electric Provider (REP) As defined in P.U.C. SUBST. R. 25.5, Definitions, an Entity that sells electric energy to retail Customers in Texas but does not own or operate generation assets and is not an MOU or EC.
Retail Entity An MOU, generation and transmission cooperative or distribution cooperative that offers Customer Choice; REP; or IOU that has not unbundled pursuant to Public Utility Regulatory Act (PURA), TEX. UTIL. CODE ANN. § 39.051 (Vernon 1998 & Supp. 2007).
Revenue Quality Meter For EPS Meters, a meter that complies with the Protocols and the Settlement Metering Operating Guide. For TSP- or DSP-metered Entities, a meter that complies with Governmental Authority-approved meter standards, or the Protocols and the Operating Guides.