Glossary of Key Energy Terms - Quick Reference Definitions, Acronyms, and Jargon

A   B   C   D   E   F  G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   #

Contact Us

Terms are described in the context of energy strategy




ACEEE - American Council for an Energy-Efficient Economy

AFV - Alternative Fuel Vehicle

AGA - American Gas Association

Allowed return on equity

Alpha (investing)

Alternative Fuels

Ambient Intelligence

Objects, that through sensors and communication, draw data from their surroundings.  More

AMI - Advance Metering Infrastructure

Anaerobic digester

Equipment used in the production of biogas

Analytic model

Ancillary Services

Services supporting the energy industry and energy value chain

Electric power transmission support services

  • Frequency Regulation
  • Voltage Control
  • Spinning Reserve
  • Non-spinning Reserve
  • Black Start

Natural gas support services

Renewable energy support services

ANSI - American National Standards Institute

APPA - American Public Power Association


ASME - American Society of Mechanical Engineers. ASME website

Asset Management

Asset Performance



Backup power (grid)

Backup power (building or system)

BACT - Best Available Current Technology

Baseload - load of power available 24 hours a day, regardless of demand


bbl - Barrel

Unit of measure for crude oil

bcf - billion cubic feet (unit measure)

A unit measure of natural gas for volume in gas reserves

bcm - billion cubic meters (unit measure)

A unit measure of Natural Gas used in production and distribution


Behind the Meter

BESS - Battery Energy Storage System

Part of an (ESS) Energy Storage System. The BESS is a container system comprised of a (SM) Storage Moduel and (PCS) Power Conversion System

Battery Energy Storage System - see BESS

Beta (investing)

Beta (software, technology)


BIPV - Building Integrated Photovoltaic (solar, equipment, technology)

Black start (ancillary service)


A distributed, timestamped, database which is managed autonomously using a peer-to-peer network. Example: Bitcoin

BPMI - Barclays Capital Power Margin Index (finance, investing)

BPS - Bulk Power Systems

Generation and transmission (G&T)

Bulk storage

Book Value (finance)

Boutique Firm

Brent, Brent Crude

A classification of oil from the North Sea, recognized internationally as a benchmark for other classifications and market pricing

BTMG - Behind the Meter Generation

BTU - British Thermal Unit

Business model




C-Rating (batteries)


CA - Carbon Abatement

CAES - Compressed Air Energy Storage (storage, battery)

CAGR - Compound Annual Growth Rate (finance)

CAIR - Clear Air Interstate Rules (regulatory)

CAISO - CAlifornia ISO

an Independent System Operator serving California

CAPM - Capital Asset Pricing Model (finance)



Capacity Auction

Capacity Firming

Capacity Payments

charges paid to generators for a set capacity 

Carbon monoxide

CCM - Construction Compliance Management

CERTS—Consortium for Electric Reliability Technology Solutions

CH4 - Methane

Channel Partners

Charge/Discharge (battery, storage)

CHP - Combined Heat and Power

Combining 2 generation methods where the waste heat produced by the first turbine turbine generator is used by a second steam turbine to produce electricity.  See also cogen, cogeneration, combined cycle.

CIM - Construction Inspection Management

CIP - Critical Infrastructure Protection (USA)

Clean energy


Cleantech Group

Cleantech Innovation Index (finance)

CNG - Compressed Natural Gas

CoGen - Co-Generation

See CHP - Combined Heat and Power. 

Community solar



Co-op - Cooperative Utility

A utility organized as a cooperative, owned and managed by the people who use the utility.

CC- Combined Cycle

CCCT - Combined Cycle Combustion Turbine

CCM - Construction Compliance Management

CCPP - Combined Cycle Power Plant

CCGT - Combined Cycle Gas Turbine

CGA - Common Ground Alliance

CPP - Critical Peak Pricing

Commerce Commission (Regulatory)

Commissioning (O&M, asset)

Congestion relief

Corporate Transformation

Cryoelectronics, Cryotronics

The study and use of superconductivity at very low temperatures


The production or use of supercooling to store energy or to convert gas fuels into a liquid state

CT - Combustion Turbine (generation)

Method used by many natural gas powered generators.  Detailed description

CTG - Cleantech Group

CTG Monitor

Curtailment Services

Customer Experience

See also Voice of the Customer, VOC.

C & I - Commercial & Industrial

Cycle Time (battery)

Duration of storage per charge (unit = hours)

Cycle life (battery, storage)



Dark Spread

The margin on coal or nuclear power production in areas dominated by gas

Deal flow

Deal origination

Deal sourcing




Consulting firm specializing in utility customer experience research. website

Demand charge reduction

Demand Response

Methods of reducing peak demand on a system. DR can be applied before the meter or after the meter. 


Deployment of capital (finance)

DER - Distributed Energy Resources


  • Distributed Generation: small to mid-size solar, wind, biofuel (often renewables)
  • Microgrid: islanding, community
  • Energy Storage: batteries

DER Asset Optimization

DER Database

DER Economics Tool

DER Market Penetration Tool

DER Site Selection Tool

DER System Impact

DER model


DERMS - Distributed Energy Resource Management Systems

DERP - Distributed Energy Resources Provider

Developer (energy)

Developer (technology, IT)

Development Bank (finance)

DIMP - Distribution Integrity Management Plan,
by PHMSA, US Department of Transportation

DIRT - Damage Information Reporting Tool, Common Ground Alliance (CGA)

DG - Distributed Generation

On-site or near-site, often renewables private generation on a smaller than utility scale: solar, wind, biofuel, etc.

DG - Directorate General (Europe)

Digital Energy

DIMP - Distribution Integrity Management Program

Discharge rate (battery)

Dispatch Curve 

A cumulative supply curve by generator type. The order in which generators are used as demand increases.

Distressed Assets (finance)

District energy solution (gas, midstream?)



Distribution losses

Diversified company

Diversified portfolio (finance)

DOE - Department of Energy (government)



DR - Demand Response

DR - Distributed resources (aka. Distributed Energy Resources)

DRAM - Demand Response Auction Mechanism

DSM - Demand Side Management

Management of programs designed to reduce end use consumption of energy and fuels. This includes Utility and State Energy Efficiency and Demand Response programs.

Duck Curve

A duck shaped curve representing utility scaled electric energy production over the course of a day

Duration (battery, storage)



Early Stage (finance)

EBITDA - Earnings Before Interest, Taxes, Depreciation and Amortization (finance)

E&D - Exploration and Development


EDC - Economic Development Corporation

EE - Energy Efficiency

EEI - Edison Electric Institute

 An electric industry trade organization  website

EERS - Energy Efficiency Resource Standards

Regulatory mandates to increase energy efficiency

EES - Electrical Energy Storage

EIA - Energy Information Administration (government)

Electrical storage

Using electrostatic or electromagnetic technologies to store energy
Examples: UltraCap, SMES

Electro-chemical storage

The use of electro-chemical technologies to store energy
Examples: cell and flow batteries

EM field - Electro-magnetic field


EMS - Energy Management Systems


The ability to perform work (unit = watt-hours)

Energy cloud

Energy density

Energy intensity

How much energy it takes to produce a unit of GDP.  A lower number indicates greater efficiency.

Energy management

Energy Storage System (ESS)

The ESS is comprised of: (SM) Storage Moduel, (BOS) Balance of System, and (PCS) Power Conversion System

Energy Value Chain - Upstream, Midstream, Downstream

Segments of the fuel supply chain from extraction (gas) / generation (electric) through processing, transmission and distribution to the end use


Enovation = Energy + Innovation

Illustrative portmanteau and tagline of Enovation Partners

Enovation Partners

Strategy consulting and advisory firm specializing in energy and infrastructure


EP - Enovation Partners

EPA - Environmental Protection Agency (government)

EPC - Engineering Procurement and Construction

EPRI - Electric Power Research Institute (industry organization)

ERCOT - Electric Reliability Council of Texas (government)


ESCO - Energy Service Company (service)

ESS - Energy Storage Systems

A general term encompassing batteries and other energy storage technologies




FCM - Forward Capacity Market

FERC - Federal Energy Regulatory Commission (government, regulatory)

FERC Major Orders

FERC Order 755 - Frequency Regulation Compensation in the Organized Wholesale Power Markets

"pay-for-performance" compensation for regulation resources based on actual service provided

FERC Order 888 - Promoting Wholesale Competition Through Open Access Non-discriminatory Transmission Services by Public Utilities; Recovery of Stranded Costs by Public Utilities and Transmitting Utilities

Established open, non-discriminatory access to utility-owned transmission infrastructure

FERC Order 889

FERC Order 980

Established “an open, transparent, and coordinated transmission planning process”

FERC Order 1000 - Transmission Planning and Cost Allocation

Requires planners to give non-transmission alternatives (example: batteries) comparable consideration

FGD - Flue Gas Desulfurization (process)

Flow batteries (battery, storage, technology)

Rechargeable electrochemical battery

Flywheel (storage, technology)

A rotating mechanical device to store energy

Frequency Regulation (Ancillary Service, process)

Synchronizing generation assets within the tolerance bounds for AC on the electric grid. More

FTC - Federal Trade Commission (USA, regulatory)

Fuel Cell

Fuel Switching

Fugitive Gas

Fund-of-Funds (investing)




Gas (natural gas)

Gas (petroleum)

Gas (state - solid, liquid, gas)

Gas processing



Geothermal energy

General Rate Case (regulatory)

Calculated future earnings based on rate and market assumptions

GHG - Greenhouse Gas

GPS - Global Positioning System (technology)

GRC - General Rate Case (regulatory)

Greenhouse Emissions

Greenfield (investing)


Grid energy storage

Energy storage resources used to support the energy grid during intermitant supply (often wind and solar generation), increase in demand, and outage conditions. 

Grid scale

See also utility scale

Grid Security (physical)

Grid Security (cyber)

Growth strategy

G&T - Generation & Transmission

GTI - Gas Technology Institute. website

GTL - Gas to Liquid

GUI - Graphical User Interface

GW - Gigawatts (unit measure, electric power)

GWh - Gigawatt hour (unit measure, electric energy)



Haitz's Law  - growth prediction of LEDs

Heat Map

Heat Rate

A measure of generator efficiency, how many BTU does it take to produce 1 kWh.  

Heat recapture

See also recuperator, and HRSG

Hedge (finance, risk, investing)

Henry Hub Spot Price

Henry Hub is a distribution point for a natural gas pipeline in Louisiana.  Historically it sets the price for natural gas in North America on the spot market and the futures market.

HERS - Home Energy Rating Standard

HRSG - Heat Recovery Steam Generation

See also Recuperator, Heat Recapture




IEA - International Energy Agency

IGU - International Gas Union (industry organization)

Impact Investing

Investments made with the goal of supporting social and environmental causes

In the money




Initiatives led by members of the energy industry to solve energy industry problems.  Often this is a consortium of energy companies, research institutions, and industry organizations.


Hard installed assets used to transport energy from one location to another. Examples: pipelines, transmission towers, electric wires, transformers

Infrastructure Integrity

The ability of infrastructure to resist an outage or leakage, and to maintain working order

Infrastructure Resilience

The ability of infrastructure to recover from an outage or leakage, and return to working order

INGAA - Interstate Natural Gas Pipline Association of America (trade). INGAA website 


Innovation Index

Installed base

Integration toolkit

Intelligent Inspection

Mobile technology and big data assisted analysis, often field inspections of energy infrastructure.


See also rectifier

IoT - Internet of Things

Technology and non-technology objects connected to the internet, creating "ambient intelligence."  Often networked with each other and containing sensor data and remote activation functionality.

Examples: Smart vehicles, smart buildings, smart home appliances,

IOU - Investor Owned Utilities

Privately owned utilities. Other ownerships include: public utilities, municipal utilities, and coops.

IPP - Independent Power Producer

A non utility producer of electric power for sale
See also Merchant Power Producer and NUG

IRR - Internal Rate of Return (finance)

Island (energy, grid)

ISO - Independent System Operator

ITC (subsidy)




JV - Joint Venture



KW - Kilowatts (unit measure, electric power)

KWh - Kilowatt hour (unit measure, electric energy)



Late Stage (finance)

LCE - Lithium Carbonate Equivalent

LCOD - Levelized Cost of Delivery (finance)

A cost comparison of different energy delivery mechanisms and options

LCOE - Levelized Cost of Energy (finance)

An industry benchmark and annual study by Lazard comparing alternative energy to conventional energy technologies.  LCOE 10.0

LCOS - Levelized Cost of Storage (finance)

The storage version of Lazard's industry benchmark, LCOE. A methodology for comparing energy storage technologies, the annual report is published by Lazard and ongoing development with Enovation Partners. More

LDC - Local Distribution Company

Lead based (battery)  

Lead acid

Leak detection

LED - Light Emitting Diode

A very energy efficient lighting technology

Levelized Cost of Delivery - see LCOD above

Levelized Cost of Energy - see LCOE above

Levelized Cost of Storage - see LCOS above


Lifespan (batteries)

Maximum number of cycles before significant degradation

Li-Ion - Lithium Ion (battery)

Liquidity (finance, investing)


The process of converting a gas into its liquid state; often used for storage and transportation

Litigation Support

Load Following

LP - Limited Partnership

LNG - Liquified Natural Gas


The amount of electricity in a system at a point in time

Load loss

LPG - Liquified Petroleum Gas




M2M - Machine to Machine

Machine Learning


Market Assessment

Market Insights

Market Intelligence

Market Value

Mechanical storage

An energy storage technology which uses rotation, gravity, or pressure to store energy
Examples: Flywheel, Pumped Hydro, Hydraulics


The odor added to natural gas to detect leakage

Merchant Power Producers (see also IPP)

Non-utility owned generators which sell their production at unregulated rates

Metal-air batteries





Midstream Natural Gas

Midstream Electric


The RTO servicing portions of the upper Midwest states and Canada

MLP - Master Limited Partnership (finance, investing)

This is a common partnership structure for investing in energy infrastructure and midstream assets; MLPs have certain tax advantages


Moore's Law - growth prediction of semi-conductors


A utility which provides more than one energy or resource. Such as:

Electric and Natural Gas utility

Power and Light (P&L) utility

Water and Gas utility


Munis - Municipalities 

A self-governing urban political jurisdiction. A city government. The territory governed under a jurisdiction.

MW - Megawatts (unit measure, electric power)

MWh - megawatt hour (unit measure, electric energy)




NaS - Sodium-sulfur

NEM - Net Energy Metering

See Net Metering.

NERC - North American Energy Reliability Council

Net Market Exposure (finance, investing)

Net Metering

NGL (pipeline?)

NGV - Natural Gas Vehicle

NIST - National Institute of Standards and Technology

Non-recourse debt (finance)

Non-spinning reserve (Ancillary Service)

NOx - Nitrogen Oxides emissions

NREL - National Renewable Energy Laboratory

NUG- Non-Utility Generator (aka. IPP, Independent Power Producer)

NYSERDA - New York State Energy Research and Development Authority



Opportunistic (investing)


O & M - Operations & Maintenance

OTD - Operations Technology Development

OTM - Office of Technology Management



PCS - Power Conversion System

PE - Private Equity

Peak Shaving

Methods used reduce or mitigate high demand which would strain the system or be cost prohibitive.  This might include the use of Demand Response (DR) and battery energy storage.

Peaking Plant

A plant or generator which is used  to provide incremental supply when demand exceeds a certain level

Performance contract

Performance improvement (O&M)

Permanent Load Shift

See Load Shift


PHMSA - Pipeline and Hazardous Materials Safety Administration, United States Department of Transportation. PHMSA website

Pipes and Wires




Pipeline integrity

PJM- Pennsylvania, (New) Jersey, Massachusetts

P&L - Profit and Loss (finance, management, investing)

P&L is on of the three primary financial statements which  is used to report company financials to management and investors.

P&L - Power and Light (utility)

A type of utility which provides both power (usually electric or gas) and light to its customers

PPA - Power Purchase Agreement

PP&E - Property Plant & Equipment (accounting, assets)

Physical capital which is essential to business operations and is not easy to liquidate

Policy (regulatory)

Portfolio (investing, finance, management)

Portfolio simulation (investing, assets)



The rate at which energy is delivered (unit = Watts)

Power Conversion System - see PCS above

Power Management

Power utility

A utility which provides power (usually electric, oil, or natural gas) to its service territory

PQ - Power Quality

PQ - Poor Quality

Price signals


PSC - Public Service Commission (State Regulator)

PSSE, PSS/E - Power System Simulation for Engineers

PUC - Public Utilities Commission (State Regulator)

PUD - Public Utility District (utility)

Public utility serving an area, often a County

Public Utility

Pumped Storage

Pumped Hydro

PURPA - Public Utility Regulatory Policy Act

Private Utility

Program Implementation

Project financing


Proprietary Database

PTC (subsidy)

PV - Photovoltaic

PV Integration

P2P - Peer to Peer




QA - Quality Assurance

QC - Quality Control

QF - Qualified Facility

Qualified Purchaser (investing)




Ramping support

Rate case

Rate class

Rate Base

The regulated return earned by a utility on the assets it owns

RCA - Risk and Compliance Assessment


R&D - Research & Development

RE - Renewable Energy

Energy produced from renewable sources. Examples: solar, wind, hydroelectric, geothermal, biofuels

REC - Renewable Energy Credit (incentive, subsidy)

RECIP - Renewable Energy Competitive Incentive Program (incentive)

Incentive to deploy cost-effective renewable energy 

Recip - Reciprocating (engine, generation)

Reciprocating engine

Type of engine which uses pistons to turn gas pressure (usually steam) into rotating motion to produce power. These engines are often fueled by natural gas and used to power equipment for gas pipelines and gas processing.




Reg A

Reg D



Regulated Utility

Regenerative energy

Renewable Energy

Reserve power


Customer or market of energy use at home by equipment installed at the site


Resource Aggregation

Resource Efficiency

Resource Efficiency definition by EC: "using the earth's limited resources in a sustainable manner while minimising impacts on the environment. It allows us to create more with less and to deliver greater value with less input." more

Retail Energy

Risk arbitrage (investing)



ROCE - Return on Capital Employed or Return on Common Equity (finance, investing, management)

ROI - Return On Investment (finance, investing, management)

ROIC - Return On Invested Capital (finance, investing)

RPA - Risk and Performance Assurance

An inspection and performance platform developed by GTI and eight gas utilities.  More
A phase of Construction Compliance Management (CCM

RPM - Reliability Pricing Model

RPS - Renewable Portfolio Standards


RTO - Regional Transmission Organizations

Examples: New England RTO, NY ISO, PJM Interconnection, MISO, SPP RTO, ERCOT ISO, California ISO



SCADA - Supervisory Control And Data Acquisition


SCR - Selective Catalytic Reduction


SEIA - Solar Energy Industries Association

SEPA - Smart Energy Power Alliance

Service reliability

Service territory


SM - Storage Module

A rack level system and component of an (ESS) Energy Storage System and an (BESS) Battery Energy Storage System

SMES - Superconducting Magnetic Energy Storage

A short duration energy storage technology which uses a superconducting magnetic coil which has been cryogenically chilled. This energy storage technology has a very low loss of energy.

SMR - Small Modular Reactor (generation)

Specific energy

Specific power

Spinning Reserve (Ancillary Service)

The reserve each generator must have in case the largest generator on the grid fails. Grid resilience.  More

Spread (investing)

Small Power Production Facility

Renewable fuel sourced generation facility producing less that 80 MW as defined by the Federal Power Act


Smart cities

Smart grid

Smart home

Smart meter

SNL Energy

SNR - Signal to Noise Ratio

Solar array

Solar Developer

Solar Strategy

Solar Survey

Solar Thermal

Solid-state batteries

SOx - Sulfur Dioxide emissions

Spark Spread

The margin earned on gas power in an area dominated by gas

Special purpose vehicle

Spot price

    Stacked use case

    Combining multiple use applications of a technology. Stacked use case in LCOS analysis example.

    Stranded Cost

    The decline in asset value when the price of power falls below its production cost


    • Corporate Strategy
    • Business Unit Strategy
    • Portfolio Strategy
    • Technology Strategy

    Stray voltage

    Storage (Energy Storage)

    Bulk storage

    Data Storage

    Energy Storage

    • Battery
    • Fuel Cell
    • Pumped Storage
    • Flywheel

    Fuel storage

    Storage during processing or refinement

    Substation power


    Supply Chain


    Syngas and synthesis gas



    TAM - Total Addressable Market, Total Available Market, Total Annual Market

    Tariffs (regulatory)

    tcf - trillion cubic feet (unit measure)

    A unit measure of volume in gas reserves

    Tcf - Total Cubic Feet (unit measure)

    Measure of a gas

    T&D - Transmission & Distribution

    T&D deferral

    Using technologies to extend the life of existing transmission equipment

    Thermal runaway

    Thermal storage of energy

    A storage technology which uses very low or very high temperatures to store energy
    Examples: ice, molten salt

    Throughput (operations)

    Time Shift

    TIMP - Transmission Integrity Management Plan

    TOU Pricing - Time of Use Pricing


    Transaction Support

    Transactive Energy - TE - (electric) 

    Energy prices set by transactions between all grid participants instead of regulated bodies.  more



    The Long-haul transportation of liquid and gas fuels (via pipes) and electricity (via wires) 

    Transmission support


    TSR - Total Shareholder Return

    TWh - Total Watts

    Measure of electricity



    UCRC - Utility Customer Research Consortium

    Unregulated Utility

    UPS - Uninterruptible Power Supply

    Power supply used to recover from outages. More

    Upgrade deferral

    Using technology to delay the expense of replacement or upgrade of equipment or other assets


    Use Case

    USRE - Utility Scale Renewable Energy


    Regulated and deregulated utilities provide services (such as: oil, gas, electric, telecommunication, or water) to a defined geography or one or more service territories. 


    Electric utility

    (Natural) Gas utility


    Water utility

    Utility of the Future

    The expanded role of the energy utility after the widespread application and adoption of Distributed Energy Resources (DER) such as renewable energy generation and energy storage technologies, and greater customer engagement.

    Utility scale


    Grid energy




    Value at risk

    Value Proposition


    VC - Venture Capital

    Virtual Power Plants

    VOC - Voice of the Customer / Consumer

    VOC - Volatile Organic Compounds (materials)

    Voice of the Customer / Consumer - VOC


    Voltage control

    The maintenance of consistent voltage in an electrical system. 

    Voltage support

    VOST - Value of Solar Tariff



    WACC - Weighted Average Cost of Capital (finance)

    Water utility


    Watt (unit measure, electric power)

    Wh - Watt hour (unit measure, electric energy)

    Wholesale (energy)

    WEI - Western Electric Institute

    Well to Wheels

    The transformation process of a fuel from raw material to end use - in this example a vehicle.  See also energy value chain

    Wind Developer







    Yield (finance, investing)

    Yield (operations, management)



    ZNE - Zero Net Energy (buildings)

    A system that generates the energy equivalent of what it consumes, often applied to buildings




    4CP - Four Critical Periods:  June, July, August, September

    Peak and spike use which can influence annual averages. Most relevant for utilities in hot climates such as Texas