Glossary - d

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
DA Day Ahead
DAS Data Aggregation System
DC Direct current
DLF Distribution Loss Factor
DRS Down Regulation Services
Data Aggregation The process of netting, grouping and summing Load consumption data, applying appropriate profiles, Transmission Loss Factors, and Distribution Loss Factors and calculating and allocating UFE to determine each QSE and/or Load Serving Entities responsibility by Settlement Interval by Congestion Zone and by other prescribed aggregation determinants.
Data Aggregation System The database and communication system that will collect meter data from TDSPs and directly polled meters in ERCOT. The system will perform aggregation functions to the Load data in order to satisfy certain objectives such as providing TDSPs with Load share data to use in billing Competitive Retailers, assigning QSE Load responsibility, and assisting Competitive Retailers and QSEs in their settlement responsibilities. The data will also be compiled along Congestion and weather zones.
Data Archive An integrated normalized data structure of all the target source systems' transactions. The population of the data archive will be an extraction of data from the transaction systems without transforming the data. The Data Archive will be 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 is generally lightly indexed.
Day Ahead The twenty-four hour period prior to the beginning of the Operating Day.
Delivery Plan A plan by ERCOT containing the hours and levels of operation that an RMR Unit, including Synchronous Condenser Unit, is instructed to operate.
Demand Instantaneous or integrated power consumption
Direct Current Tie, DC Tie Any non-synchronous transmission interconnections between ERCOT and non-ERCOT electric power systems.
Direct Load Control Controlling select end-use equipment (e.g. A/C, water heaters) for purposes of reducing energy consumption during select periods.
Dispatch The act of issuing Dispatch Instructions.
Dispatch Instruction(s) Specific command(s) issued by ERCOT to QSEs or TDSPs during the course of operating the ERCOT System.
Distribution Loss Factor The ratio of the Distribution Service Provider's estimated Distribution Losses to the total amount of energy deemed consumed (IDR plus profiled consumption) on the Distribution Service Provider's system.
Distribution Losses The difference between the energy delivered to the Distribution System and the energy consumed by Loads connected to the Distribution System.
Distribution Service Provider An Entity that owns and maintains a Distribution System for the delivery of energy from the ERCOT Transmission Grid to the Customer.
Distribution System That portion of an electric delivery system operating at under 60 kilovolts (kV) that provides electric service to Customers or Wholesale Customers.
DUNS Number A unique nine-digit common company identifier used in electronic commerce transactions.
Dynamic Schedule A Real Time telemetered signal to ERCOT derived from an actual metered Load that represents an energy Obligation and Resource in a QSE schedule, as further described in Section 4, Scheduling.