Basic Smart Grid Terms and Acronyms

A

Advanced metering infrastructure (AMI)

.

Alternative generation

Power produced from green sources such as solar, hydropower, wind, and marine that emit little CO2 into the atmosphere.

Ancillary services

Services and support systems that aid in electricity transmission from power plants to customers, i.e., load regulation.

Appliances

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Includes generally residential items, tools, and systems powered by electricity, including heating and cooling, lighting, refrigerators, washers/dryers, computer systems, electronics.

Asset management

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Refers to procedures and policies intended to control costs, reduce risk, enhance performance, improve investment and project scheduling decisions, and deal with aged equipment.

Average System Availability Index (ASAI)

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A measure of reliability that is expressed as the percentage of time the electrical system is available.

Automated meter reading (AMR)

.

Sensor-equipped meters capable of retrieving and transmitting power consumption and other information.

B

Bank

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A group of connected transformers or capacitors—a capacitor bank, for example.

Biomass

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Considered a renewable fuel source for power generation. Includes wood and wood waste, municipal solid waste, crops, and biogas.

Blackout

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A large-scale disruption in power supply caused by storms, age-related failure, exceeded line capacity, human error.

British thermal unit (BTU)

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Standard unit of measurement of a quantity of heat energy.

Broadband over power line (BPL)

.

Broadband Internet access made available over standard power lines.

Brownout

.

An intentional voltage reduction on the grid intended to lessen load during shortages. Used in integrated networks.

Building automation system (BAS)

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A system capable of computerized monitoring and control of a building's lighting and mechanical systems, and monitoring for performance and potential failure.

Business case

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A decision-making process intended to ascertain how a specific decision will affect profitability, and how cash flow, costs, and revenue will change.

Bypass

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Equipment designed to provide continuous service when a meter is being tested or replaced.

C

Capacitor

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Stores energy, but in a manner completely different from a battery. Found in handheld electronics and have many additional uses.

Capital cost

The one-time setup cost of a project such as a generating plant, distinct and separate from continuing operating costs.

Circuit

The conductor or path taken by electricity when it flows between terminals that are the source of supply.

Circuit breaker

Senses electrical overload and breaks a circuit.

Climate change

Although recently used interchangeably with global warming, the term more accurately refers to a wide range of natural shifts in climate, including cooling.

Closed circuit

A fully-connected circuit capable of delivering electric current.

.

Cogeneration

The reuse of thermal energy by connecting thermal electric generation with a thermal process, such as an industrial application.

Combined pump storage plant

A hydroelectric pumped storage facility that uses pumped water and stream flow to generate electricity.

Command and Control

Control centers capable of monitoring and managing the Smart Grid, providing remote diagnosis, and remote repair in some instances.

Compressed air energy storage (CAES)

Pre-compressed air, frequently stored in mines or salt caverns appropriate for the purpose.

Conductor

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A pathway or wire through which electrical current flows.

Congestion

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Excessive demand on the electric transmission network, typically resulting in a congestion charge to consumers to offset increased cost.

Conservation voltage regulation (or reduction) (CVR)

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Limiting voltage provided to electricity consumers to reduce demand and conserve energy.

Cooperative (coop)

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Non-profit, consumer-owned utility in rural areas of the U.S.

Critical Infrastructure Protection (CIP)

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Administered by NERC, CIP standards are intended to safeguard the North American bulk power system from attack and ensure utility compliance.

Current

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Electricity flow through a circuit. Measured in amperes.

Current transformer

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Steps current down by a fixed amount so that it can be measured and recorded.

Customer Average Interruption Duration Index (CAIDI)

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A measure of reliability that represents the average number of hours of each service interruption.

Customer information system (CIS)

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A software application for handling customer calls, billing, and related operations.

D

DC

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Electricity that flows in one direction only. Abbreviation for direct current.

Decommission

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To take a nuclear generating facility out of service.

Demand response  (DR)

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A Smart Grid feature that allows consumers to reduce or change their electrical use patterns during peak demand, usually in exchange for a financial incentive.

Demand side management (DSM)

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Programs intended to encourage customers to modify the levels and patterns of their electricity consumption.

Deregulation

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The removal of regulations over a formerly-regulated industry or part of an industry.

Distribution

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Delivering electricity from a local substation to nearby residences and businesses.

Distribution automation (DA)

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Programs and technologies designed for an intelligent grid to ensure consistent power quality and reliability and accommodate two-way power flows.

Distributed intelligence

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Sensors and other monitoring devices in remote locations intended for long-term operation in the field.

Distributed generation

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Brings small-scale power generation facilities, particularly renewables, close to consumers to boost efficiency while lowering costs and reducing environmental risks.

Distributed temperature sensing (DTS)

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Remote sensors designed to monitor and regularly report temperature data along transmission and distribution feeders.

E

Electric energy

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Typically refers to kilowatt hours in the electricity industry.

Electric power

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Specifically, the rate of energy transfer, usually referred to as megawatts.

Electric power grid

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Interconnected networks that provide electricity generation, transmission, and distribution—and the lines, substations, and other associated equipment.

Electric Power Research Institute (EPRI)

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An independent public interest energy and environmental research organization that focuses on challenges related to electric power.

Electric utility

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Public or privately-held companies that generate and/or deliver electricity in exchange for payment at rates set by an outside regulating authority.

Electric vehicle (EV)

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A vehicle propelled exclusively by one or more electric motors.

Electromagnetic field (EMF)

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A force field associated with an electric charge in motion that includes electric and magnetic components, commonly originating from high-voltage transmission lines.

Energy Independence and Security Act (EISA)

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Enacted by Congress in 2007 to direct national energy policy. Title XIII of the act established the Federal Smart Grid Task Force.

Energy service provider

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Typically an energy company that provides services to end users.

F

Fault

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A problem at a point in an electrical circuit, such as a short circuit.

Federal Energy Regulatory Commission (FERC)

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An independent agency responsible for regulating interstate transmission of electricity, high-voltage transmission systems, wholesale electricity sales, and aspects of oil, gas, and hydroelectric operations.

Federal Power Commission (FPC)

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Eliminated in 1977 and succeeded by the Department of Energy.

Flow battery

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Rechargeable high power and very high storage capacity battery, and used to level loads on the electrical grid.

G

Generation

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Includes all forms of electricity production, such as coal- and gas-fired power plants, hydroelectric plants, and wind, and solar, and geothermal production.

Geographic information system (GIS)

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Digitally stores, analyzes, manages, and relays location-oriented data. Numerous GIS software applications are available.

Geothermal energy

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Taps the heat energy from fluids deep within the earth, and can be used directly for heating or for electricity production.

Gigawatt (gW)

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One billion watts, or 1,000 megawatts.

Global warming

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Gradual temperature increase near the Earth's surface created by cyclical climate changes and, increasingly, pollution from burning fossil fuels and other manmade sources.

Greenhouse gases

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Gases such as water vapor, carbon dioxide, a variety of fluorocarbons, and methane that thicken the atmosphere and trap radiant energy near the Earth's surface.

Green power

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Another term for renewable energy.

H

Home area network (HAN)

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Includes simple computer networking within the home and bundled data, voice, and video services provided by telephone companies.

Home automation network

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Monitoring and control systems for residential use such as heating and lighting controls, security, and appliance and electronics power consumption.

Hydroelectric plant

.

A power plant that incorporates turbines generally driven by falling water.

I

Institute of Electrical and Electronics Engineers (IEEE)

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Professional association dedicated to technology advancement and innovation, standards development, and publications.

International Electrotechnical Commission (IEC)

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A non-governmental agency responsible for developing and publishing international standards for electrical, electronic, and associated technologies.

Intelligent heuristic analysis system

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A computer application that matches specific user requirements to its selection of methods to be used in data analysis.

Interruptible load

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Electrical service that can be suspended during electric grid emergencies. Interruption is authorized by prior agreement between provider and consumer.

Investor-owned utility (IOU)

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A privately-held utility (not operated by a government entity or a consumer cooperative).

Independent system operator (ISO)

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An organization established by FERC to control and monitor electric power system operations, typically within one state.

Islanding

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The ability to use distributed generation to provide power when storms or other events have knocked out the utility's ability to provide power.

K

Kilovolt (kV)

.

1,000 volts.

Kilowatt (kW)

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1,000 watts, which can be expressed as the amount of electricity required to illuminate ten 100-watt light bulbs.

Kilowatt hour (kWh)

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Electricity provided at the rate of 1,000 watts for one hour.

L

Line loss

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The amount of electricity lost—usually two to three percent of the total—on high-voltage transmission lines.

Load management

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A collection of strategies intended to reduce or move demand from peak to off-peak periods.

Load shifting

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Another term for load management.

M

Megawatt (MW)

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1,000 kW. A megawatt is the standard measurement unit for electricity generation.

Metering

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Generally refers to any type of metering system, such as old electromechanical meters, and the advanced smart meters that are replacing them.

Microhydropower

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Small-scale hydropower plant producing less than 100 kW of power (10 kW is enough to power a large home).

Microturbines

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Small combustion turbines capable of producing between 25 kW and 500 kW of power.

MultiSpeak

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Software interoperability specification intended to assist utilities in automation and data exchange between software applications.

N

National Institute of Standards and Technology (NIST)

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A U.S. Department of Commerce agency charged with identifying and evaluating standards and technologies relevant to Smart Grid adoption.

Net metering

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Net metering allows consumers who contribute power to the grid to receive credit for at least a portion of that electricity.

Non-renewable energy

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Electricity generation from sources that may only be used once, including natural gas, nuclear, and coal sources.

Nuclear Regulatory Commission (NRC)

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Federal regulatory agency responsible for monitoring safety of nuclear reactors and radioactive materials, storage and disposal, and licensing.

O

Off peak

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A period of reduced electrical demand.

Outage management

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Incorporates technologies such as GIS and smart meters to quickly locate and manage outages.

P

Peak demand

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The period of time when demand for electricity is at its highest.

Peaking gas turbine plant

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More energy-efficient than traditional gas turbines, and used in compressed air generation and storage systems.

Phantom load

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Refers to power use in appliances after they are turned off. Almost all electronics, clocks, and remote controls continue to consume power, even when "off."

Phasor measurement unit (PMU)

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Phasors help detect and mitigate congestion at various points on the grid by sampling voltage and current several times a second.

Photovoltaic (PV) system

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Solar cells grouped in modules, then linked together in arrays to transform sunlight into electricity. R&D in materials and systems is accelerating phenomenally.

Plug-in hybrid electric vehicle (PHEV)

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Power plants include both rechargeable batteries and internal combustion engines. Toyota's Prius and Honda's Insight are examples of popular PHEVs.

Polychlorinated biphenyls (PCBs)

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Extremely toxic and stable chemicals used in the manufacture of transformers, capacitors, lubricants, and some household items until banned in 1979.

Power electronics

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Energy storage systems, power converters, control systems, and system integration hardware used in power transmission and distribution.

Protection

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Recent legislation has been introduced in the U.S. Senate to give federal regulators more authority to secure the electrical grid and protect it from cyberattack.

Public utility commission (PUC)

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A state agency responsible for setting rates and regulating services and other activities of electric, gas, and telecommunications utilities operating within its state boundaries.

Public utility district (PUD)

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A single-purpose district established for the generation, transmission, and distribution of electricity or other services. Boundaries frequently extend beyond local jurisdictions.

Purchased power

.

Electricity bought from other providers.

R

Rate

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The charges electric utilities assess customers for power delivery, expressed per unit or level of use over a fixed time period, i.e., monthly.

Rate base

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A utility's property value that determines the utility's permitted rate of return. That rate is set by a regulatory agency.

Rate case

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A request filed by an electric utility for a consumer price increase with the appropriate state public utility commissions.

Rate of return

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Expressed as a percentage. Rate of return represents the ratio of net operating income a utility earns and determined as a percentage of its rate base.

Rate schedule

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Incorporates the financial terms and conditions of an electric utility that delivers service to its customers.

Real-time pricing

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A policy of charging consumers varying rates for a service to reflect frequent cost fluctuations occurring over time, as opposed to fixed pricing.

Receipts

.

Fuel purchases.

Regional transmission operator (RTO)

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An organization established at the direction of FERC to control the electrical power transmission system in a service area that extends beyond state borders.

Regulation

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The overall responsibilities of government agencies that oversee industries, including monitoring and administering enforcement of compliance with applicable laws and policies.

Reliability

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Consistent, cost-effective delivery of quality electric power. Reliability is a primary issue addressed by the Smart Grid and industry restructuring.

Renewable energy

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Power provided by renewable sources such as wind, solar, geothermal, hydro, and biomass.

Residential

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The class of consumers who use electricity to power heating and lighting systems and appliances in private homes or apartment dwellings.

Rolling blackout

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An intentional disruption that rotates through small areas to avoid a full-scale blackout and to reduce customer inconvenience. Used in radial systems.

S

Supervisory Control and Data Acquisition (SCADA)

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A computer system that monitors an industrial, infrastructure, or facility-based control process.

Security

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Issues largely pertain to cyberattacks and other intentional grid disruptions. Regulators have accused the industry of trying to avoid complying with security standards.

Sensor

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A significant component of the electrical grid, sensors are used in several ways: temperature monitoring, security, providing data for peak demand adjustment. They are an integral component of a Smart Grid.

Service area

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Territory defined as the area utilities are required to or have the right to provide electricity to consumers.

Short circuit

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An unintended low-resistance electrical connection that can cause circuit damage, overheating, and other problems.

Single-phase service

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Usually 120-volt or 240-volt service for homes and businesses.

Smart Grid

.

A digitization and modernization plan for an intelligent electric grid intended to conserve energy, reduce costs, and increase reliability and energy independence.

Smart meter

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Gathers and transmits detailed consumption data back to the local utility for monitoring and billing. Also monitors for power quality and outages.

Solar energy

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Energy from the sun converted to electricity by a photovoltaic system incorporating solar cells (panels).

Solid waste energy

.

Another term for biomass.

Standards

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Critical to the industry, codified and administered standards ensure reliability, efficiency, and interoperability. Typically administered by government entities such as FERC and state PUCs.

Step down

.

To reduce circuit voltage with a transformer.

Step up

.

To increase circuit voltage with a transformer.

Storage

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A general term for a variety of power storage technologies, including pumped storage, fuel cells, batteries, flywheels, and more.

Substation

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The site where equipment for switching or regulating electrical voltage is located.

Sustained outage

.

.A power outage of more than two minutes.

Synchrophasor (synchronized phasor)

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.Takes real-time measurements of the amount of electricity throughout a system. Can improve reliability by providing data for precise load management.

T

Thermal limit

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The most electricity a transmission line can bear without risk of damage caused by heat deterioration.

Three-phase service

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Electric service to manufacturing and other industries and facilities that usually require more power than 120 volts or 240 volts.

Tidal energy

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Energy generated by focusing the ebb and flow of ocean tides through reversible turbines located in a dam.

Time of day rate

.

The rate charged to electric utility customers based on the varying costs of delivering service at different times throughout the day.

Time of use (TOU)

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An energy cost reduction measure that permits consumers to operate during off-peak hours.

Transmission

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The delivery of bulk high-voltage electricity from the generating plant to substations and the distribution system.

Turbine

.

Equipment that produces rotary mechanical power from water, steam, or hot gas.

U

Ultracapacitor

.

A capacitor used in large-scale applications, such as powering a bus.

V

Voltage

.

A measurement of the force of electric current.

W

Worldwide Interoperability for Microwave Access (WiMAX)

Wireless transmission based on the IEEE802.16 standard for mobile Internet access, using multiple links for transmission. Similar to Wi-Fi but covers larger areas.

Wind energy

Power generated by the motion of the wind captured by large propeller-like blades and transmitted to wind turbines.

Workforce management system (WFM)

Automates operations such as handling trouble calls, repair crew dispatch, tracking field services, and enhancing communications.