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 network of distributed energy resources—like rooftop solar panels, electric vehicle chargers, and smart water heaters—that work together to balance energy supply and demand on a large scale. They are usually run by local utility companies that oversee this balancing act.

Often described as the “pressure” that pushes electric current through a circuit. It’s measured in volts (V) and is essentially the energy per unit charge. Think of it like water pressure: the higher the voltage, the greater the “push” on electrons, and the more current can flow.

Maintaining stable voltage on the grid  is critical to keeping the lights on and avoiding equipment damage. Voltage is not consistent across the grid, though it is locally constant, with higher voltages used for longer transmission lines and lower voltages used at the distribution level.

• Voltage support – The ability of a power system to maintain stable voltage levels within a desired range, even during fluctuations or disturbances. It’s crucial for ensuring a reliable electricity supply and preventing equipment damage. Generally, it is achieved by a grid maintaining reactive power via generating units or other equipment absorbing or adding reactive power.