Glossary - D

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


Term/Acronym Definition
DAM Day-Ahead Market
DAS Data Aggregation System
DASPP Day-Ahead Settlement Point Price
DC Direct current
DC TIE Direct Current Tie
DG Distributed Generation
DLC Direct Load Control
DLF Distribution Loss Factor
DRG Distributed Renewable Generation
DRS Down Regulation Services
DRUC Day-Ahead Reliability Unit Commitment
DSC Debt Service Coverage
DSP Distribution Service Provider
DSR Dynamically Scheduled Resource
DUNS Data Universal Numbering System
DUNS # DUNS Number
Data Aggregation The process of netting, grouping, and summing Load consumption data, applying appropriate profiles, Transmission Loss Factors (TLFs), and Distribution Loss Factors (DLFs) and calculating and allocating UFE to determine each QSE and/or Load Serving Entity’s (LSE’s) responsibility by Settlement Interval by Load Zone and by other prescribed aggregation determinants.
Data Aggregation System (DAS) The database and communication system that collects meter data from TSPs, DSPs and ERCOT Polled Settlement (EPS) Meters. The system performs aggregation functions to Load data in order to satisfy certain objectives, such as providing TSPs with Load share data to use in billing CRs, assigning QSE Load responsibility, and assisting CRs and QSEs in their Settlement responsibilities. The data is also compiled along Load and Weather Zones.
Data Archive An integrated normalized data structure of all the target source systems’ transactions. The population of the Data Archive is an extraction of data from the transaction systems without altering the data. The Data Archive is used to populate the Data Warehouse.

Data Warehouse

De-normalized data stored in a schema, physically optimized to handle high volumes of data and concurrent user access, and generally lightly indexed.

Day-Ahead The 24-hour period before the start of the Operating Day.
Day-Ahead Market (DAM) A daily, co-optimized market in the Day-Ahead for Ancillary Service capacity, certain CRRs, and forward financial energy transactions.
Day-Ahead Market (DAM) Energy Bid A proposal to buy energy in the DAM at a Settlement Point at a monotonically decreasing price with increasing quantity.
Day-Ahead Market (DAM) Energy-Only Offer A QSE’s willingness to sell energy at or above a certain price and at a certain quantity at a specific Settlement Point in the DAM. A DAM Energy-Only Offer Curve may be offered only in the DAM. DAM Energy-Only Offer Curves are not Resource-specific.
Day-Ahead Market (DAM) Resettlement Statement See Settlement Statement
Day-Ahead Market (DAM) Statement See Settlement Statement
Day-Ahead Market (DAM)-Committed Interval A Settlement Interval for which the Resource has been committed due to a DAM award.
Day-Ahead Operations The Day-Ahead process consisting of the DAM and Day-Ahead Reliability Unit Commitment (DRUC).
Day-Ahead Reliability Unit Commitment (DRUC) A Reliability Unit Commitment (RUC) process performed for the next Operating Day.

Decommissioned Generation Resource

A Generation Resource for which a Resource Entity has submitted a Notification of Suspension of Operations, for which ERCOT has declined to execute an RMR Agreement, and which has been decommissioned and retired.

Delivery Plan A plan by ERCOT containing the hours and levels of operation that an RMR Unit, including a Synchronous Condenser Unit, is instructed to operate.
Demand The amount of instantaneous electric power in MW delivered at any specified point or points on a system.
Designated Representative A responsible natural person authorized by the owners or operators of a renewable Resource to register that Resource with ERCOT.
Digital Certificate An electronic file installed on a programmatic interface or an individual's assigned computer used to authenticate that the interface or individual is authorized for secure electronic messaging with ERCOT's computer systems.
Direct Current Tie (DC Tie) Any non-synchronous transmission interconnections between ERCOT and non-ERCOT electric power systems.
Direct Current Tie (DC Tie) Load A Load used to represent the withdrawal of power from the ERCOT System to a DC Tie.
Direct Current Tie (DC Tie) Resource A Resource used to represent the injection of power into the ERCOT System from a DC Tie.
Direct Current Tie (DC Tie) Schedule An energy schedule between ERCOT and a non-ERCOT Control Area and is represented by a corresponding Electronic Tag (e-Tag) that contains the physical transaction information such as the Settlement Point energy amount (MW), the associated DC Tie, and the buyer and seller.
Direct Load Control (DLC) The control of end-use equipment (e.g., air conditioning equipment, water heaters) to reduce or increase energy consumption during select periods.
Dispatch The act of issuing Dispatch Instructions.

Dispatch Instruction

A specific command issued by ERCOT to a QSE, TSP or DSP in the operation of the ERCOT System.

Dispute Contact The individual associated with a Market Participant who is the primary contact with ERCOT regarding the pursuit of an Alternative Dispute Resolution (ADR) request.
Distributed Generation (DG) An electrical generating facility located at a Customer’s point of delivery (point of common coupling) ten megawatts (MW) or less and connected at a voltage less than or equal to 60 kilovolts (kV) which may be connected in parallel operation to the utility system.
Distributed Renewable Generation (DRG) Electric generation with a capacity of not more than 2,000 kW provided by a renewable energy technology that is installed on a retail electric Customer’s side of the meter.
Distribution Loss Factor (DLF) The ratio of a DSP’s estimated Distribution Losses to the total amount of energy deemed consumed (Interval Data Recorder (IDR) plus profiled consumption) on the DSP’s system.
Distribution Losses The difference between the energy delivered to the Distribution System and the energy consumed by Customers connected to the Distribution System.
Distribution Service Provider (DSP) An Entity that owns or operates a Distribution System for the delivery of energy from the ERCOT Transmission Grid to Customers.

Distribution System

That portion of an electric delivery system operating under 60 kV that provides electric service to Customers or Wholesale Customers.

DUNS Number A unique nine-digit common company identifier used in electronic commerce transactions, supplied by the Data Universal Numbering System (DUNS).
Dynamic Rating The current-carrying capability of a Transmission Element adjusted to take into account the effect of ambient weather conditions.
Dynamic Rating Processor A process used to establish ERCOT Transmission Element limits based upon factors such as ambient temperature and wind speed.
Dynamically Scheduled Resource (DSR) A Resource that has been designated by the QSE, and approved by ERCOT, as a DSR status-type and that follows a DSR Load.
Dynamically Scheduled Resource (DSR) Load A Load that a QSE designates to be followed by a Dynamically Scheduled Resource (DSR).