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)

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.

(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). 

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.

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. 

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.

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.

An independent agency that regulates the interstate transmission of natural gas, oil, and electricity. FERC also regulates natural gas and hydropower projects.

A United States law primarily regulating the interstate transmission and sale of electricity and the development of hydroelectric power. It was responsible for creating the body now known as FERC. It was created in 1920 and has been amended several times since. 

Measures taken to ensure backup power, particularly of renewable energy, such as solar and wind generators. These requirements may require battery storage, ancillary services, or backup generation, such as an added gas plant to produce energy when a solar or wind plant does not.

Electricity is supplied to homes and businesses in the United States in the form of alternating current, and frequency is the rate at which an alternating current changes direction, as measured in hertz (Hz). Across the power grid there is a consistent frequency which in the United States is 60 Hz. 

The ability of the grid to react to a change in

the frequency to bring it back to the normal operating frequency, which is 60 Hz in the United States

• Inertial response refers to the injection of stored energy, such as battery energy, into the electricity grid to slow down a decline in frequency. 
• Primary frequency response – The first line of defense against frequency fluctuations that could destabilize the grid. It takes the form of immediate, automatic adjustments in power output by generators and loads in response to frequency deviations in the electric grid.
• Fast frequency response consists of the combined inertial response and primary frequency response. It injects energy in the seconds immediately following a disturbance to slow frequency decline and establishes the minimum frequency (called the nadir).
• Secondary frequency response works on a slightly longer time frame than primary frequency response, on the order of 5-15 minutes. It maintains grid frequency and allows for scheduled energy transfers between balancing authorities, which include utilities, regional transmission operators, and other grid management entities.

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.

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.

Equipment used to increase and decrease voltages at grid interfaces.

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.