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”.
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.
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:
Midcontinent Independent System Operator, serves northern Midwest, southeast, and parts of Canada
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.
Power that does not perform useful work but is used to establish and maintain electromagnetic fields that are needed to generate, transmit, and convert electric power in the alternating current network. A shortage of reactive power can cause voltage to decline. (See also: voltage support)
A characteristic of the whole electricity system to describe its ability to consistently deliver electricity to consumers without interruption, even through grid disturbances. Reliability comes down to having sufficient generating resources to meet demand and a functional operational grid system.
An agreement initiated by an RTO or ISO with a power plant, keeping it in operation temporarily for reliability purposes.
The ability of the grid to ride through extreme events, recover quickly, and support other critical systems (e.g., transportation, health care, public safety etc.).
An assessment of whether the current or projected resource mix is sufficient to meet capacity and energy needs for a particular grid. The resource mix includes all resources able to provide capacity and energy to the system. Adequacy assessments are used to identify potential shortfalls in the availability of resources across different time frames; from long-term planning (5 to 20+ years) to seasonal and day-ahead assessments.
(see also: ISO) – A non-profit organization that manages the electricity transmission system in a specific region, ensuring reliable and efficient electricity delivery. RTOs operate the high-voltage electricity grid, facilitating the movement of power from generating plants to substations and ultimately to consumers. They also oversee competitive wholesale electricity markets.
Measure of the rate of energy transfer over a unit of time, with one watt equal to one joule (J) per second.
A form of renewable energy that uses the kinetic energy of wind to generate electricity. It involves capturing the wind’s energy through turbines, which then convert this mechanical energy into electricity. Modern wind power generation primarily relies on wind turbines, often grouped into wind farms, connected to the electrical grid.
