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.
The mechanism for choosing the lowest cost energy option that meets energy needs, which gives cheaper renewable energy and battery storage an edge.
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.
Measures that reduce electricity use in a home or business. These measures include replacing inefficient heating and air conditioners with heat pumps, adding attic insulation, and sealing ducts and foundation, walls, roof, windows, and doors of buildings. It also includes replacing energy-intensive appliances with more efficient ones. These measures can provide energy savings, improve comfort, and increase property values.
Connecting new generation to the grid with minimal transmission upgrades and managing impacts through operational strategies rather than extensive upfront infrastructure investments. This approach, often referred to as “connect and manage,” prioritizes adding generation capacity quickly while relying on the grid operator to manage any resulting operational constraints. It requires new resources to risk curtailment (where the generator is asked to stop supplying power to the grid when supply is too high). The process has allowed Texas’ ERCOT to connect record numbers of new clean projects in the last several years significantly faster than other regions.
The Electric Reliability Council of Texas serves as an independent system operator (ISO), managing the flow of electrical power over transmission infrastructure in the state of Texas.
A combination of automated and manual controls grid operators adjust to maintain grid reliability by ensuring a balance between supply (generation) and demand (load). They generally consist of three main aspects:
An entity that is hired by an Independent System Operator (ISO) or Regional Transmission Organization (RTO) to oversee and assess the operations of the wholesale electricity market. Its primary role is to ensure fair and competitive market practices by monitoring market participant behavior and identifying potential market manipulation or design flaws.
A non-profit organization that manages the electricity grid and wholesale electricity markets within a specific geographic region. Its primary role is to ensure the reliable and efficient delivery of electricity, balancing supply and demand in real-time and overseeing fair competition among market participants.
In the context of the grid, it refers to the energy stored in the rotating machinery of generators, such as the turbines of a gas plant or hydropower station.
The turbines rotate at the same rate as the grid–60 cycles per second (hertz) in the United States–and help provide stability for the grid, particularly during spikes in power demand or other disturbances. If the power plant goes offline for any reason, the inertia of the turbines maintains the grid’s frequency for a window of time while another power source is brought online to replace the offline generator.
Certain types of renewable energy, such as wind and solar photovoltaic, do not use rotational generators, instead using electronic inverters. But these renewable technologies include electronic sensors that can respond to changes in frequency quickly, and can replace the need for rotational inertia.Synthetic inertia – Inertia provided without synchronous generators and refers to the transfer of active power into the grid from a grid-forming inverter. This type of inertia can provide the same, or even better, stabilization services as traditional inertia because it has an instantaneous effect.
The process of connecting new power sources, like renewable energy generators or energy storage systems, to the existing grid infrastructure. It involves integrating these new sources with the grid’s transmission and distribution networks, ensuring a stable and reliable flow of electricity.
The line in which power generation and transmission projects must wait after they have requested to connect to the electric grid. These queues are managed by grid operators like ISOs (Independent System Operators) or RTOs (Regional Transmission Organizations). Projects are evaluated for their impact on the grid and the necessary upgrades before they can connect and deliver electricity.
A power source whose availability and output fluctuate due to natural variations in its energy source. This means the power supply isn’t consistently available, often linked to weather conditions like wind speed, time of day, or season. Renewable energy output can be forecast and stored in battery systems to maintain grid reliability.
Technology that provides the interface between the grid and energy sources like solar panels, wind turbines, and energy storage, converting direct current to alternating current (which is how electricity is delivered in the United States). It is used to convert power output from solar cells, batteries, and wind turbines into power that can be injected into the grid.
A power generation or storage device (such as a battery) that connects to the electrical grid through an inverter, a power electronic device that converts direct current (DC) to alternating current (AC). These resources, including solar photovoltaic (PV) systems, wind turbines, and battery energy storage systems, are increasingly important for grid stability.
ISO New England
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.
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.
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.
