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.

Can’t find the term you’re looking for? Submit it here!

202(c) Order

An emergency order issued by the United States Department of Energy (DOE) under Section 202(c) of the Federal Power Act. It allows the Secretary of Energy to temporarily order connections of facilities and the generation, delivery, or transmission of electricity to best meet an emergency caused by war, a sudden increase in demand, or a shortage of energy or facilities. These temporary orders can also exempt power plants from federal, state, or local environmental rules and have historically been used to prevent outages during severe weather events or supply shortfalls.

Large load

Historically refers to industrial facilities with high electrical demand. They had long interconnection timelines that allowed for more study time under traditional planning processes. Currently, emerging large loads include cryptocurrency mining, data centers (conventional and artificial intelligence), oil field loads, and hydrogen production facilities. Many have a shorter timeline to interconnect (months vs. years) to the grid. In addition to these rapid timelines, some emerging large loads introduce new challenges to grid operators like rapid demand fluctuations and increased voltage sensitivity.

Load

The amount of power or electricity consumed by a device or system at a given time. It’s the demand placed on an energy source, like a power grid or a battery, by the connected electrical equipment.

Load growth

The increase in the demand for electricity over time. It signifies the rising need for power from various sectors, including residential, commercial, and industrial, and can be driven by factors like population increases, economic development, and the adoption of new technologies like electric vehicles and data centers.

Load shed

A controlled process where a utility company reduces or shuts off power supply to certain areas or customers to balance demand with available supply, preventing a complete system failure. It’s a last-resort measure to maintain grid stability when demand exceeds supply or when there are issues with power generation or transmission.

Locational Marginal Price (LMP)

A way for wholesale electric energy prices to reflect the value of electric energy at different locations, accounting for the patterns of load, generation, and the physical limits of the transmission system.

Loss of Load Expectation (LOLE)

Analysis is typically performed on a system to determine the amount of capacity that needs to be installed to meet the desired reliability target, commonly expressed as an expected value, or LOLE of 0.1 days/year.

Offshore wind

Wind turbines erected in bodies of water that harness the power of wind, converting it into electricity that is then transmitted to the mainland to power homes and businesses. Offshore wind farms are considered a renewable energy source.

Operational reliability

The real-time balancing of energy supply and demand to maintain frequency and voltage within safe operating limits. It is the shorter-term dimension of reliability and requires regular monitoring and control of the entire grid. It includes the ability to quickly respond to sudden changes, like the loss of a major power plant or transmission line, and to handle normal variations in supply and demand.

Queue

(see: Interconnection Queue)

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.

Transfer capacity

The maximum amount of electrical power that can be reliably moved from one geographic region of the power grid to another, essentially indicating the ability of the transmission lines connecting those regions to transport electricity between them without causing instability or exceeding safety limits. It’s a crucial concept for ensuring the safe and efficient operation of the power system, particularly in the context of electricity markets and grid planning.

Transformers

Equipment used to increase and decrease voltages at grid interfaces.

Transmission

The process (and infrastructure) of moving large amounts of electrical power over long distances from where it is generated, like a power plant, to substations closer to consumers.

Glossary Form

Your Name(Required)

Contact Us

We’re glad you are here!
For any inquiries or to contact one of our experts please fill out our form.
This field is for validation purposes and should be left unchanged.
© 2025 All rights reserved The Reliable Grid Project.