Grid Glossary

TRENDING TERM

Critical Issue Fast Path (CIFP)

An accelerated stakeholder process used in PJM Interconnection to resolve urgent, contentious, and time-sensitive issues that cannot be resolved through the normal stakeholder process. The process involves several stages of discussion and proposal development, culminating in a submission to the Federal Energy Regulatory Commission (FERC) for approval. The CIFP process has been used in recent years to discuss large load additions (2025) and resource adequacy (2023).

TRENDING TERM

Effective Load Carrying Capability (ELCC)

Measurement used to calculate how much an energy resource–such as a wind farm or solar array–contributes to the overall reliability of the grid. It assesses the resource’s ability to meet electricity demand, particularly during peak usage periods, and is especially useful for variable renewable energy sources whose output depends on factors like weather conditions. 

TRENDING TERM

Disturbance

Refers to any unwanted or unplanned electrical event that interferes with the normal operation of the electrical grid. These can manifest in power outages, surges, and other events, and can originate from various sources within the electrical grid, such as loss of a large generating unit or another grid asset, such as a transmission line or transformer.

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Active power

Also known as real or true power, is the portion of electrical power that does useful work in a circuit, such as generating heat, light, or mechanical energy. (see related: reactive power)

Advance Notice of Proposed Rulemaking (ANOPR)

A preliminary document used by government agencies to solicit public feedback on potential new rules or reforms before they are officially proposed. It outlines initial ideas, asks specific questions, and serves as the first step in a larger regulatory process. The acronym is frequently used by the Federal Energy Regulatory Commission (FERC). It precedes a formal Notice of Proposed Rulemaking (NOPR) and allows agencies to gauge public opinion and gather information to develop a more informed proposal.

Ancillary services

(see also: Essential reliability services) – Supplementary services essential for maintaining the reliable operation and stability of the electrical grid beyond the basic generation and transmission of energy. They are “behind-the-scenes” services that include real-time balancing of electricity supply and demand, maintaining voltage levels, and providing the capability to restart the grid after a widespread outage (black start). 

Automatic Generation Control (AGC)

Is an automated system that continuously monitors the electrical network and adjusts the power output of multiple generators. Its primary functions are to maintain system frequency (60 Hz in United States), in response to changes in the power demand, or load.

Baseload

The minimum amount of electricity that a utility must provide to meet the consistent, ongoing needs of its customers. Historically, this steady demand was met by large power plants (like coal or nuclear) that ran continuously. Today, with more renewable energy, this minimum demand can be met by a flexible mix of various power sources, rather than relying solely on specific “baseload plants”.

  • Baseload capacity:  The generating equipment normally operated to serve loads on an around-the-clock basis.
  • Baseload plant:  A plant, usually housing high-efficiency steam-electric units, which produces electricity at an essentially constant rate and runs continuously. 
Battery Energy Storage System (BESS)

A technology that stores electrical energy in rechargeable batteries for later use. Batteries help stabilize the grid, manage energy demand, and increase the use of renewable energy.

Behind-the-meter

Any energy resource that provides energy directly to a home or business without passing through a utility company’s meter. Examples include rooftop solar and microgrids.

Generation

The process of creating electricity. 

Geothermal energy

Heat derived from the Earth’s interior, which can be harnessed for electricity generation. It’s a renewable resource, as the Earth’s internal heat is continuously replenished.

Grid

The electrical grid is a vast, interconnected network comprising power plants, transmission lines, substations, and distribution lines. Its purpose is to generate, transmit, and deliver electricity from producers to consumers across a wide geographic area. 

Grid enhancing technologies (GETs)

A variety of technologies that improve the capacity, efficiency, and reliability of existing power grids. They are often lower cost and faster to deploy than major grid infrastructure upgrades like building new transmission lines. These technologies optimize the flow of electricity across existing infrastructure.

Grid following inverter

Refers to the ability of an inverter to synchronize with frequency and voltage on the grid. These are more common than grid forming and refer to how this technology takes its cues from the grid, not the other way around.

Grid forming inverter

Refers to the ability of an inverter to actively control frequency and voltage on the grid, helping to ensure grid stability. They can provide ancillary services, such as inertia, voltage regulation, and frequency response, essential for maintaining grid stability.

Grid hardening

Refers to the many solutions that help the grid withstand major events, such as extreme weather, natural disasters, or cyber attacks, without disruption.

National Association of Regulatory Utility Commissioners (NARUC)

A non-profit organization that represents state public service commissions, which regulate essential utility services like energy, telecommunications, and water. Its stated aim is to improve the quality and effectiveness of public utility regulation. It has eight committees:

  1. Consumer Affairs
  2. Critical Infrastructure
  3. Electricity
  4. Energy Resources & Environment
  5. Gas
  6. International Relations
  7. Telecommunications
  8. Water

It also has a task force focused on Innovation.

NERC

Non-profit organization that operates to assure the effective and efficient reduction of risks to the reliability and security of the grid. It oversees six regional reliability entities and encompasses all of the interconnected power systems of Canada and the contiguous United States, as well as a portion of the Mexican state of Baja California. Its responsibilities include working with all stakeholders to develop standards for power system operation, monitoring and enforcing compliance with those standards, assessing resource adequacy, and providing educational and training resources as part of an accreditation program. NERC also investigates and analyzes the causes of significant power system disturbances in order to help prevent future events and produces reports about the near and long-term reliability forecast.

Notice of Proposed Rulemaking (NOPR)

A document used by government agencies to announce a potential new rule or amendment to an existing one. This is an official part of the law-making process, allowing public comment before the rule is finalized. The acronym is frequently used by the Federal Energy Regulatory Commission (FERC).

NREL

A government-owned, contractor-operated facility, funded and overseen by the United States Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE). It specializes in the research and development of renewable energy, energy efficiency, energy systems integration, and sustainable transportation.

NYISO

New York ISO

Thermal source

A type of power station in which the heat energy generated from various fuel sources (e.g., coal, natural gas, nuclear fuel, etc.) is converted to electrical energy.

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