Glossary - N

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
NCI Notice of Change of Information
NERC North American Electric Reliability Corporation
NESC National Electrical Safety Code
NFRC Non-Frequency Responsive Capacity
NIST National Institute of Standards and Technology
NOIE Non Opt-In Entity
NOMCR Network Operations Model Change Request
NON-SPIN Non-Spinning Reserve
NSA Network Security Analysis
NWSIDR Non-Weather Sensitive IDR
Net Dependable Capability The maximum sustained capability of a Resource as demonstrated by performance testing.
Net Generation Gross generation less station auxiliary Load or other internal unit power requirements metered at or adjusted to the POI with the ERCOT Transmission Grid at the common switchyard.
Network Operations Model A representation of the ERCOT System providing the complete physical network definition, characteristics, ratings, and operational limits of all elements of the ERCOT Transmission Grid and other information from TSPs, Resource Entities, and QSEs.
Network Security Analysis A processor used by ERCOT to monitor Transmission Elements in the ERCOT Transmission Grid for limit violations and to verify Electrical Bus voltage limits to be within a percentage tolerance as outlined in the Operating Guides.
Non-Competitive Constraint A contingency and limiting Transmission Element pair or group of Transmission Elements associated with a GTC that is not determined to be a Competitive Constraint under the process defined in Section 3.19, Constraint Competitiveness Tests.

Non-Frequency Responsive Capacity (NFRC)

The telemetered portion of a Generation Resource’s HSL that represents the sustainable non-Dispatched power augmentation capability from duct firing, inlet air cooling, auxiliary boilers, or other methods which does not immediately respond, arrest, or stabilize frequency excursions during the first minutes following a disturbance without secondary frequency response or instructions from ERCOT.

Non-Metered Load

Load that is not required to be metered by applicable transmission or distribution tariff.

Non-Modeled Generator A generator that is:
  1. Capable of providing net output of energy to the ERCOT System;
  2. Ten MW or less in size; or greater than ten MW and registered with the PUCT according to P.U.C. SUBST. R. 25.109, Registration of Power Generation Companies and Self-Generators, as a self-generator; and
  3. Registered with ERCOT as a Non-Modeled Generator, which means that the generator may not participate in the Ancillary Service or energy markets, RUC, or SCED.
Non-Opt In Entity (NOIE) An EC or MOU that does not offer Customer Choice.
Non-Opt-In Entity (NOIE) Load Zone A Load Zone established by a NOIE or a group of NOIEs using a one-time NOIE election.

Non-Spinning Reserve (Non-Spin) Service

An Ancillary Service that is provided through use of the part of Off-Line Generation Resources that can be synchronized and ramped to a specified output level within 30 minutes (or Load Resources that can be interrupted within 30 minutes) and that can operate (or Load Resources that can be interrupted) at a specified output level for at least one hour. Non-Spin may also be provided from unloaded On-Line capacity that meets the 30-minute response requirements and that is reserved exclusively for use for this service.

Normal Ramp Rate The rate of change (up and down) in MW per minute of a Resource, which is specified by the QSE to ERCOT by up to ten segments; each segment represents a single MW per minute value (across the capacity of the Resource) that describe the available rate of change for the given range (between HSL and LSL) of generation or consumption of a Resource. In Real-Time SCED Dispatch, the up and down Normal Ramp Rates are telemetered by the QSE to ERCOT and represent the total capacity (in MW) that the Resource can change from its current actual generation or consumption within the next five minutes divided by five.
Normal Rating See Rating

North American Electric Reliability Corporation (NERC) Regional Entity

An Entity with delegated authority from the North American Electric Reliability Corporation (NERC) and approved by the Federal Energy Regulatory Commission (FERC) to propose and enforce NERC Reliability Standards in the ERCOT Region.

Notice or Notification The sending of information by an Entity to Market Participants, ERCOT, or others, as called for in these Protocols. Notice or Notification may be sent by electronic mail, facsimile transmission, or U.S. mail.