Key Energy Terms
Speaking the same language
Our economy’s rapid electrification will require discussion among the public, regulators and legislators; that requires a shared vocabulary, which you’ll find here.
By speaking a shared energy language, we can all be advocates for building our nation’s energy future.
Three Components of the Power Grid
Generation
The process of creating electricity at a power plant or facility. Popular fuel sources include natural gas, coal, nuclear, wind, biomass, solar and hydro.
Transmission
A network of high-voltage lines and substations acting as an energy superhighway. Transmission brings generated electricity to populated areas for distribution.
Distribution
The network of power lines located along streets, and the wires that bring the generated electricity into our homes and businesses.
Grid Terms Glossary
GENERAL
Bulk Electric System
All transmission elements operated at 100 kV or higher and real power/reactive power resources connected at 100 kV or higher (as defined by the NERC) have this designation.
Bulk Power System
This describes the facilities and control systems necessary for operating an interconnected electric energy network and the electric energy from generation facilities needed to maintain transmission system reliability (as defined by NERC).
Clean Energy
This type of energy is generated without emitting greenhouse gases.
Congestion
This occurs when a transmission grid has become overloaded and the lowest-priced electricity cannot flow freely to a specific area.
Distribution
Distribution lines are the most visible component of power delivery. These are the wires seen along streets, bringing electricity into homes and businesses.
Easement
Utilities often obtain a right to use property to construct, operate and maintain infrastructure for the good of the community without owning that property. Term often used interchangeably with “Rights-Of-Way”.
Fossil Fuels
This natural, nonrenewable fuel source was formed from the remains of living organisms.
Generation
Electricity can be created from other forms of energy at a power plant or facility. Fuel sources include natural gas, coal, nuclear, wind, biomass, solar, hydro and others.
Generation (Centralized)
Centralized generation creates power in bulk. This method leverages economies of scale to minimize the cost of converting other forms of energy into electricity.
Generation (Distributed)
Solar, wind, hydro and other emerging technologies generate power at a small scale and are connected to the electric power grid.
Kilovolt (kV)
Electrical potential or voltage is measured in these units and often used to distinguish transmission line capacity.
Megawatt (MW)
Equal to one million watts, this power measurement unit is commonly used to describe the amount of instantaneous electricity that can be produced by generation or demanded by load.
Microgrid
A microgrid is a local energy system that is capable of operating independently from the main transmission grid.
Outages – Momentary, Sustained
A momentary, or transient outage, is generally under 60 seconds in duration and automatically restored without human intervention. A sustained outage lasts more than 60 seconds and usually requires human intervention to resolve. Generally, transmission circuit outages do not equate to customer outages.
Permitting
Legal authorization is required to construct, maintain or improve infrastructure – this is the process of permitting.
Planning
All stakeholders work together in the planning stage to develop a vision for infrastructure.
Reliability
A power system must be evaluated for its ability to withstand natural and human-made disturbances.
Renewable Energy
This type of energy is generated from natural resources that can replenish themselves.
Resiliency
A power system and its components are evaluated for their ability to minimize damage and improve recovery from non-routine disruptions in a reasonable amount of time. This includes responses to high-impact, low-frequency events.
Resource Adequacy
Energy generation capacity is evaluated according to demands across an electric system.
Rights-of-Way
Legal rights allowing someone to pass along a specific route over property they do not own. Term often used interchangeably with “Easement”.
Siting Process
The process by which infrastructure projects select a suitable location for the placement of facilities, taking into consideration the environmental and land ownership impacts and striving for the most community benefit.
Smart Grid
New technology offering greater information and control over energy use.
The Grid
A complex network that distributes electricity, often referred to as the “power grid,” “electric(al) grid” or simply “the grid.” The U.S. grid is actually comprised of three different grids, run by a patchwork of different utilities, independent system operators (ISOs) and regional transmission organizations (RTOs).
Transmission
A network of high-voltage lines and substations act as an energy superhighway, connecting power generation facilities to the local distribution system.
REGULATORY ENTITIES
FERC: Federal Energy Regulatory Commission
An independent regulatory entity overseeing the interstate transmission of natural gas, oil and electricity in the United States.
Independent System Operator (ISO)
Entities that emerged from FERC Orders 888/889 to safely and reliably operate power grids within specific regions.
Regional Transmission Organization (RTO)
Independent regional entities that operate transmission facilities and are responsible for short-term reliability and management of congestion on the transmission system, as well as planning for expansion of the transmission grid.
State Public Utility Commissions
Commissions regulate the retail sales of electricity and electric distribution for their states, as well as the siting of certain infrastructure projects.
RELIABILITY ENTITIES
NERC: North American Electric Reliability Corporation
An electric reliability organization certified by FERC that establishes, oversees and enforces reliability standards for the bulk power system in North America. Six regional organizations in North America are responsible for the reliability and security of the North American bulk electric system, in conjunction with NERC. They are as follows:
- MRO: Midwest Reliability Organization
- RFC: Reliability First Corporation
- SERC Reliability Corporation
- Texas Reliability Entity
- Northeast Power Coordinating Council
- WECC: Western Electricity Coordinating Council
POLICY
Cost Allocation
Regulators assign cost responsibility for electrical infrastructure.
NOPR: Notice of Proposed Rulemaking
A FERC-issued document that proposes changes to the commission’s current rules and regulations and seeks public comment on those changes to inform future action by FERC.
Order No. 1000
A final rule issued in 2011 which reformed FERC’s transmission planning and cost allocation requirements for public utility transmission providers.
ROFR: Right of First Refusal
ROFR policies at the federal or state level provide local electric companies with the “first option” to build regional transmission projects in their existing footprints. If the local utility chooses not to construct the project, ROFR allows regional entities to choose an alternate entity to construct. In practice, ROFRs expedite transmission planning and development, save customers time and money, and ensure that transmission systems are planned, built, operated and maintained by companies with deep knowledge of the local system who will make decisions with the long-term interest of a state and region’s residents in mind.