California ISO
The maximum amount of power an energy source can physically produce (measured in megawatts/MW), or when referring to an electrical grid, the total amount of electricity that power plants connected to the grid are capable of producing. It’s essentially the total potential output of all the electricity sources, like coal, nuclear, hydro, wind, and solar plants. Meanwhile, energy is the actual output of a source over a particular time period.
Generally, participants submit sealed bids to offer capacity at specific prices. The auction ends when the total capacity offered matches the region’s needs, and a single clearing price is set for all commitments.
An energy source that generates electricity with zero- or extremely low-carbon emissions, and can do so when needed, regardless of weather conditions. They include enhanced geothermal energy and advanced nuclear technologies. They also can include solar or wind paired with battery storage to provide on-demand power supply regardless of weather conditions or time of day.
Refers to a regulatory approach for connecting new power generators to the electrical grid, notably used in Texas (ERCOT). This approach allows new generators to connect expeditiously with minimal upfront transmission upgrades. However, the grid operator retains the right to curtail their output if transmission constraints arise. This contrasts with approaches where developers pay for upgrades prior to connection. (see Energy-only interconnection approaches)
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).
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.
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.
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.
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.
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.
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.
(see: Interconnection Queue)
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.
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.
