# List of energy abbreviations

This is a list of acronyms found in the context of energy issues.

## Contents

* 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
* Appendix: Residential energy acronyms

## A

* AAQS—Ambient Air Quality Standards (environment) (US)
* AAU—Assigned amount units (measurement)
* ABT—Availability based tariff (electricity)
* ABF—Aquatic Base Flow (Hydropower) (electricity)
* AC—Alternating current
* ACA—Annual Charge Adjustment (electricity)
* ACE—Area Control Error (electricity)
* ACEEE—American Council for an Energy-Efficient Economy
* ACRS—Accelerated Cost Recovery System (finance)
* ADITC—Accumulated Deferred Investment Tax Credit (policy)
* ADR—Asset Depreciation Range (finance)
* AEP—American Electric Power (electricity)
* AESO—Alberta Electric System Operator
* AFE—Authority for Expenditure or Authorization for Expenditure
* AFUDC—allowance for funds used during construction
* AFV—Alternative fuel vehicle
* AGA—American Gas Association
* AGC—Automatic generation control
* AGD—Associated Gas Distributors (US)
* AIEE—American Institute of Electrical Engineers
* AIMA—Agricultural Impact Mitigation Agreement (US)
* ALARP—As low as reasonably practicable
* ALJ—Administrative law judge
* AMBO—Armenia, Macedonia, Bulgaria Oil pipeline
* AMI—Advanced metering infrastructure
* AMR—Automated meter reading also known as Automatic Meter Reading
* AMRA—Automatic Meter Reading Association
* ANGTA—Alaskan Natural Gas Transportation Act of 1977 to build the Alaska gas pipeline
* ANGTS—Alaskan Natural Gas Transportation System
* ANSI—American National Standards Institute
* AOS—Authorized Overrun Service
* AP—Action Point
* APA—Administrative Procedure Act
** —Alaska Power Administration
* APE—Area of potential effect (electricity)
* API—American Petroleum Institute (oil)
* APPA—American Public Power Association (electricity)
* APR—Actual peak reduction (e.g. in demand response systems) (electricity)
* AQCR—Air Quality Control Region (US) (environment)
* ARA—(in shipping) ports of Amsterdam – Rotterdam – Antwerp (oil)
* ARR—Auction Revenue Rights (electricity)
* ASCC—Alaskan System Coordination Council
* ASE—Alliance to Save Energy
* ASTM—American Society for Testing and Materials
* ATC—Available transfer capability
* AVR—Automatic Voltage Regulator (electricity)

## B

* BA—Balancing Authority
* BA—Biological Assessment
* BACT—Best Available Control Technology
* BBL/D—Barrel per day
* BBL/SD—Barrel per day, on stream days
* BBL—barrel (42 gallons)
** —Balgzand Bacton Line (BBL Pipeline)
* BCD—Barrel per day, on calendar days
* BCF—billion cubic feet
* BCP—Blackstart Capability Plan
* BES—Bulk electric system (Electricity transmission)
* BESS—Battery Energy Storage System
* BfP—Bureau Fédéral du Plan (Belgium). (Has responsibilities over economic, social and environmental policy
* bhp—Brake horsepower
* BIA—Bureau of Indian Affairs (US)
* BIPS—Bulk Independent Power System
* BIPV—Building Integrated Photo Voltaic
* bl—Barrel
* BLM—Bureau of Land Management of United States Department of the Interior
* BLS—Bureau of Labor Statistics of United States Department of Labor
* BOE—Barrel of oil equivalent (international)
* BPA—Bonneville Power Administration (US)
* BPL—Broadband over power line
* BPS—Bulk Power System (Electricity transmission)
* BTMG—Behind The Meter Generation
* BTU—British thermal unit(s)
* BTU—Board of Trade unit (1 kWh) (UK historical)
* BTX—from BTX process, a mixture of benzene, toluene, and xylene (oil)
* BuRec—United States Bureau of Reclamation (government)
* BWR—Boiling water reactor (nuclear)

## C

* C&I—Commercial and industrial customers (Electricity transmission)
* CA—Carbon Abatement- increasing carbon-neutrality
** —Control area (EU) – The portion of the generation and transmission system controlled by a single transmission system operator. (See also TSO).
* CAA—Clean Air Act (US)
* CAEM—Center for the Advancement of Energy Markets (US)
* CAES—Compressed Air Energy Storage
* CAFE—Corporate Average Fuel Economy standards (US)
* CAISO—California Independent System Operator Corporation, a regional transmission organization. (US)
* CAM—Compact Auxiliary Module
* CAP—Capacity market programs
** —Climate Action Plan
* CAPM—Capital asset pricing model
* CARB—California Air Resources Board
* CBL—Customer Baseline Load
* CBM—Capacity Benefit Margin
* CBOB—Conventional Gasoline Blendstock for Oxygenate Blending (Motor Gasoline Blending Component)
* CC—Combined cycle see also CCPP and CCGT
* CCGT—Combined cycle gas turbine electricity generator
* CCLIP—Conditional Credit Line for Investment Projects
* CCN—Certificate of Convenience and Necessity (utilities regulation)
* CCPG—Colorado Coordinated Planning Group
* CCPP—Combined cycle power plant
* CD—Contract Demand
* CDD—Cooling degree day, a qualitative index used to reflect the demand for energy to cool a business
* CDM—Clean Development Mechanism
* CDR—Carbon dioxide removal
* CEA—Country Environmental Analysis
* CEC—California Energy Commission
** —Commission for Environmental Cooperation
** —Council of the European Communities
* CEEC—Central and Eastern European Countries
* CEMS—Continuous emissions monitoring system
* CEP—Country Environmental Profile
** —Clean Energy Partnership, a joint hydrogen-project in Europe.
* CEPS—Centre for European Policy Studies
* CEPII—Centre d'Etudes Prospectives et d'Informations Internationales Economics think tank
* CEQ—Council on Environmental Quality
* CER—Certified Emission Reduction
* CERA—Cambridge Energy Research Associates
* CERCLA—Comprehensive Environmental Response, Compensation, and Liability Act "Superfund" (US)
* CERCLIS—Comprehensive Environmental Response, Compensation, and Liability Information System (US)
* CERTS—Consortium for Electric Reliability Technology Solutions sponsored by the United States Department of Energy and California Energy Commission (US)
* CfD—Contract for difference
* CFS—cubic feet per second
* CFTC—Commodity Futures Trading Commission
* CGR—Charge Gas Recirculation, Compact Gas Ramp (like FGSU)
* CH$_4$—Methane
* CHP—Combined heat and power
* CIAC—Contributions in Aid of Construction
* CIP—Critical Infrastructure Protection (US)
** —see also EPCIP European Programme for Critical Infrastructure Protection
* CMVE—Competitive Market Value Estimate
* CNG—Compressed natural gas
* CO—Carbon monoxide
* CO$_2$—Carbon dioxide
* COC—Cost of capital
* COE—U.S. Army Corps of Engineers
* CP—Coincident Peak
** —Certificate Proceeding
* CPA—California Power Authority
* CPI—Consumer Price Index
* CPP—Critical Peak Pricing
* CPP-F—Critical peak fixed
* CPP-F—Critical peak variable
* CPS—Control Performance Standard
** —Cycles per second (hertz)
* CPUC—California Public Utilities Commission
* CREF—Caribbean Renewable Energy Facility
* CRP—Conservation Reserve Program (US)
* CRT—Capacity Reservation Tariff
* CSD—Commission for Sustainable Development (UN)
* CSEM—Center for the Study of Energy Markets (US)
* CSP—Country Strategy Paper
** —Curtailment service provider
* CT—Combustion turbine (electricity)
* CW—Cooling Water
* CZMA—Coastal Zone Management Act

## D

* DADRP—Day Ahead Demand Response Program
* DADS—Demand response Availability Data System
* DANIDA—Danish International Development Agency
* DA-RTP—RTP Day ahead real time pricing (regarding Electricity metering)
* DC—Direct current
* DCLM—Direct control load management
* DCS—Disturbance Control Standard
* DD—Dangerous Detected
* DEFG—Distributed Energy Financial Group (US)
* DEIS—Draft Environmental Impact Statement (US)
* DER—Distributed Energy Resources
* DERMS—Distributed Energy Resource Management Systems
* DF—Distribution Factor, Dual-Fuel
* DG—Distributed generation (electricity)
** —Directorate-General (EU) (government)
* DIIS—Danish Institute for International Studies (organization)
* DLC—Direct load control (regarding Load management)
* DME—Disturbance Monitoring Equipment
* DO—Dissolved oxygen
* DoD—Depth of discharge, energy drawn from a battery
* DOE—United States Department of Energy (government)
* DOE/FE—United States Department of Energy Office of Fossil Energy (government)
* DOI—United States Department of the Interior (government)
* DOT—United States Department of Transportation (government)
* DP—Distribution point
* DPI—Differential Pressure Indicator
* DR—Demand response
* DRAM—Demand Response and Advanced Metering Coalition
* DRB—Demonstrated reserve base
* DRCC—Demand Response Coordinating Council (coalition)
* DRR—Demand Response resources
* DRRC—Demand Response Research Center (California)
* DSM—Demand side management
* DSO—Distribution system operator (regarding electricity distribution)
* Dth—Dekatherm (defined as 1 million British thermal units, also written "MMBtu") (measurement)
* DTW—dealer tank wagon (as in, "oil companies setting regional dealer tank wagon pricing") (Oil)
* DU—Dangerous Undetected

## E

* E&D—Exploration and development expenses
* E/E/PE—Electrical/Electronic/Programmable Electronic
* E85—E85 fuel: A fuel containing a mixture of 85 percent ethanol and 15 percent gasoline
* E95—like E85 fuel but with less gasoline. A fuel containing a mixture of 95 percent ethanol and 5 percent gasoline
* EA—Environmental assessment as in an Environmental impact assessment
* EAR—Estimated additional resources, as in considering reserves of uranium deposits
* EC—European Commission
* ECAR—East Central Area Reliability Coordination Agreement (US)
* EPCIP—European Programme for Critical Infrastructure Protection
* ECPA—Electric Consumers Protection Act (US)
* EDC—Electric Distribution Company (electricity)
* EdF—Electricité de France
* EDRP—Emergency demand response program
* EE—Energy efficiency
* EEI—Edison Electric Institute
** —Energy Efficiency Index for European Union energy labels
* EERS—Energy Efficiency Resource Standards
* EF—Earth Fault
* EHV—Extra high voltage
* EIA—Energy Information Administration (US)
** —Environmental impact assessment (international)
* EIB—European Investment Bank
* EIM—Energy Imbalance Market (electricity)
* EIPP—Eastern Interconnection Phasor Project
* EIS—Environmental Impact Statement (US)
* ELCON—Electricity Consumers Resources Council
* EMF—Electro magnetic field
* EMP—Environmental Management Plan
* EOR—Enhanced oil recovery
* EPA—United States Environmental Protection Agency
* EPAct—Energy Policy Act of 1992 (US)
** —Energy Policy Act of 2005 (US)
* EPRI—Electric Power Research Institute (US)
* EPSA—Electric Power Supply Association
* EQR—Electric Quarterly Report
* ERA—Economic Regulatory Administration (part of United States Department of Energy
* ERCOT—Electric Reliability Council of Texas, Inc, a regional transmission organization. (US)
* ERGEG—European Regulators Group for Electricity and Gas
* ERIS—Energy Resource Interconnection Service (electricity)
* ERO—Electric Reliability Organization. The US designated NERC as its ERO.
* ERoEI—Energy returned on energy invested
* ERRA—Energy Regulators Regional Association
* ESCO—Energy service company
* ESI—Environmental Sustainability Index
* ESMAP—Energy Sector Management Assistance Programme
* ESM—Engine Safety Module
* ESP—Electrostatic precipitator
* ESS—Energy Storage System, as in grid energy storage (electricity)
* ETBE—ethyl tertiary butyl ether
* ETSO—European Transmission System Operators association
* EU—European Union
* EUC—Equipment Under Control
* EUEF—European Union Energy Facility
* EUEI—European Union Energy Initiative

## F

* FAC—Fuel Adjustment Clause
* FACTS—Flexible Alternating Current Transmission System
* FASB—Financial Accounting Standards Board
* FAT—Factory Acceptance Testing
* FBD—Function(al) Block Diagram
* FBR—fast breeder reactor
* FCITC—First Contingency Incremental Transfer Capability
* FE—Final Element
* FEIS—Final Environmental impact statement (US)
* FELCC—Firm Energy Load Carrying Capability
* FERA—Fire and Explosion Risk Assessment
* FERC—Federal Energy Regulatory Commission (U.S.)
* FG—Fuel Gas
* FGD—Flue-gas desulfurization
* FGSU—Fuel Gas Supply Unit (like CGR)
* FINESSE—Financing Energy Services for Small Scale Users
* Fishway—Fish ladder
* FLD—Functional Logic Diagram
* FLPMA—Federal Land Policy and Management Act (US)
* FME—Free market economics
* FONSI—Finding of no significant impact. See Environmental impact statement (US)
* FPA—Federal Power Act (US)
* FPC—Federal Power Commission (US)
* FPS—Firm peaking service. See Peaking power plant
* FRCC—Florida Reliability Coordinating Council (US)
* FRS—Financial Reporting System
* FS—Functional Safety
* FSA—Functional Safety Assessment
* FSM—Functional Safety Management
* FT—Firm Transportation Service
* FTA—Fault Tree Analysis
* FTC—Federal Trade Commission (US)
* FTR—Firm Transmission Rights
** —Financial Transmission Rights. See explanation in electricity markets.
* FTS—Firm transportation service
* FUA—The Fuel Use Act (US)
* FUCO—Foreign Utility Company
* FWPA—Federal Water Power Act (US)

## G

* G&T—Generation and transmission utility cooperative (electricity)
* GADS—Generating Availability Data System (electricity)
* GAL—gallon (measurement)
* GAO—Government Accountability Office (General Accounting Office) (US) (government)
* GATT—General Agreement on Tariffs and Trade (government)
* GDP—gross domestic product (economics)
* GEF—Global Environmental Facility (environment)
* Genco—Any company doing electricity generation (US) (electricity)
* GFN—Global Footprint Network
* GFSE—Global Forum on Sustainable Energy (organization)
* GIC—Gross Inland (energy) Consumption (EU) (energy)
* GHG—Greenhouse gas (climate)
* GIA—Generator Interconnection Agreement (electricity)
* GIC—Gas Inventory Charge (natural gas)
* GISB—Gas Industry Standards Board (now NAESB) (US) (natural gas)
* GLDF—Generator to Load Distribution Factor. See Load balancing (electricity)
* Gm$^3$—Billion cubic metres (measurement – gas)
* GMO—Genetically modified organism
* GMP—Green Mountain Power (US) (electricity)
* GNP—gross national product (economics)
* GNSED—Global Network for Sustainable Energy Development
* GRI—Gas Research Institute (US) (natural gas)
* GRC—General rate case (US) (regulatory)
* GridCo—Any company running a transmission grid (electricity). Also known as a TransCo (US) (electricity)
* GSF—Generator to Load Distribution Factor. See Load balancing (electricity)
* GPE—gravitational potential energy
* GPRS—Gas Pressure Reduction System
* GSR—Gas Supply Realignment (natural gas)
* Gt—Gigaton (1 billion tons) (measurement)
* GTCC—Gas Turbine Combined Cycle (electricity)
* GTI—Gas Technology Institute (US)
* Gtoe—One billion tons of oil equivalent(EU) (measurement- oil)
* GVEP—Global Village Energy Partnership (organization)
* GVW—gross vehicle weight (transportation)
* GW—Gigawatt (one billion watts) (measurement- elect)
* GWE—Gigawatt of electric energy (measurement- elect)
* GWh—Gigawatt hour (one billion watt hours) (measurement- elect)
* GWP—global warming potential (climate)

## H

* HAZOP—Hazard And Operability Study
* HCA—Host Control Area (electricity)
* HDD—Heating degree days a qualitative index used to reflect the demand for energy to heat a business (conservation)
* HERS—Home energy rating standard (conservation)
* HHI—Herfindahl–Hirschman Index (markets)
* HID—high intensity discharge (electricity)
* hp—Horsepower (measurement)
* HRSG—Heat recovery steam generation
* HTGR—high temperature gas cooled reactor (nuclear)
* HVAC—Heating, ventilation, and air conditioning (conservation)
** —High voltage alternating current (electricity)
* HVAR—Highly Valued Aquatic Resource
* HVDC—High Voltage Direct Current

## I

* I/C—Interruptible /Curtailable (electricity)
* ICAP—Installed Capacity (electricity)
* ICAP-SCR—Installed capacity special case resources (electricity)
* ICCP—Inter-Control Center Communications Protocol (electricity)
* ICE—Internal combustion engine (transportation)
* ICT—Independent Coordinator of Transmission (US) (electricity)
** —Information and Communication Technology
* IDC—Interchange Distribution Calculator (electricity)
* IEA—International Energy Agency (Paris)
* IEC—International Electrotechnical Commission
* IEM—Internal electricity market (electricity)
* IEEE—Institute of Electrical and Electronics Engineers
* IEPE—Institute of Energy Policy and Economics (France)
* IER—Incremental Energy Rate
* IET—International emission trading (policy)
* IGCC—Integrated coal gasification combined cycle
* IGIC—Interim gas inventory charge (natural gas)
* IGSC—Interim gas supply charge (natural gas)
* IGT—Institute of Gas Technology (natural gas)
* IGU—International Gas Union (natural gas)
* IHR—Incremental Heat Rate- plant monitoring (electricity)
* IIASA—International Institute for Applied System Analysis
* IJC—International Joint Commission
* ILP—Integrated Licensing Process
* INGAA—Interstate Natural Gas Association of America
* IOS—Interconnected Operations Services (electricity)
* IOU—Investor owned utility (electricity)
* IPAA—Independent Petroleum Association of America (oil)
* IPCC—Intergovernmental Panel on Climate Change (climate)
* IPP—Independent Power Producer (electricity)
* IPS/UPS—Integrated Power System/United Power System, consisting of Independent Power Systems of 12 countries bordering Russia and the Unified Power System of Russia
* IRC—ISO / RTO Council (electricity)
* IROL—Interconnection Reliability Operating Limit (electricity)
* IRP—Integrated resource planning
* IRR—Internal Rate of Return (finance)
* ISO—Independent System Operator (US) (see also TSO) Responsible for grid management, but does not own assets. (electricity)
* ISO-NE—Independent System Operator of New England, a regional transmission organization. (US) (electricity)
* ISO—NE ISO New England, Inc. (electricity)
* ISS—Interruptible Sales Service
* IT—Interruptible Transportation is gas shipment via pipeline whose delivery may be interrupted in favor of "firm shipment" contracts if there is lack of capacity. (natural gas)
* ITC—Investment tax credit (policy)
* ITS—"Interruptible Transportation Service" is gas shipment via pipeline whose delivery may be interrupted in favor of "firm shipment" contracts if there is lack of capacity. (natural gas)

## J

* JRC—Joint Research Centre
* JREC—Johannesburg Renewable Energy Coalition

## K

* koe—One kilogram oil equivalent (EU) (measurement)
* KPI—Key Performance Indicator
* kV—Kilovolt (one thousand volts) (measurement)
* kVA—One thousand volt Ampere (measurement)
* kvar—one thousand vars (measurement)
* kW—Kilowatt (one thousand watts) (measurement)
* kWE—kilowatt electric (measurement)
* kWh—Kilowatt hour (one thousand watt hours) (measurement)

## L

* LaaR—Load acting as a resource (ERCOT category) (electricity)
* LBA—Local Balancing Authority (electricity)
* LBNL—Lawrence Berkeley National Laboratory (US)
* LCOD—Levelized cost of delivery (electricity)
* LCOE—Levelized cost of energy (electricity)
* LCOS—Levelized cost of storage (electricity)
* LDC—Local distribution company (electricity)
* LE—Latest Estimate
* LED—Light Emitting Diode
* LEVP—Low Emissions Vehicle Program
* LHV—lower heating value
* Li-Ion—Lithium Ion (electricity storage)
* LIHEAP—Low Income Home Energy Assistance Program
* LIPA—Long Island Power Authority (US) (electricity)
* LLF—Load-loss factor (electricity)
* LMP—Locational marginal price/pricing. See explanation in electricity markets.
* LMR—Load Modifying Resource (electricity)
* LNG—Liquified Natural Gas
* LODF—Line Outage Distribution Factor (electricity)
* LOLE—Loss of load expectation (electricity)
* LOLP—Loss of load probability (electricity)
* LOPA—Layer of Protection Analysis
* LOTO—Lockout / tagout.
* LPG—liquefied petroleum gas
* LPN—Lender Participation Notes
* LRG—liquefied refinery gases
* LSE—Load serving entity
* LSF—Load Shift Factor
* lsfo—Low sulfur fuel oil
* LWR—light water reactor

## M

* MAAC—Mid Atlantic Area Council (US- geographically within PJM)
* MADRI—Mid Atlantic Distributed Resources Initiative (US)
* MAIN—Mid America Interconnected Network (US)
* MAOP—Maximum allowable operating pressure
* MAPP—Mid Continent Area Power Pool (US)
* MBD—million barrels per day
* MBOE—One million barrels of oil equivalent(EU)
* MBR—Market based Rates
* MBS—Macro economic Budget Support
* MBU—Main Breaker Unit
* Mcf—Roman numeral "M" for one thousand cubic feet (measurement of natural gas)
* MDAS—Meter Data Acquisition System
* MDD—Maximum Daily Delivery Obligations
* MDDQ—Maximum Daily Delivery Quantity
* MDM—Meter Data Management
* MDQ—Maximum Daily Quantities
* MECS—Manufacturing Energy Consumption Survey
* MEDREG—Mediterranean Energy Regulators
* MEDREP—Mediterranean Renewables Energy Partnership
* MER—Maximum efficient rate
* MERC—Mobile Emission Reduction Credit (MERC) (US)
* MFS—Minimum Functional Specification
* MFV—Modified fixed variable rate
* MISO—Midcontinent Independent System Operator, Inc. A regional transmission organization. (US)
* MLP—Maximum lawful price
* MLRA—Major Land Resource Areas
* MM—Used to denote million in gas usage
* MMbbl/d—one million barrels of oil per day
* MMBtu—1 million British thermal units, same as dekatherm
* MMC—Market Monitoring Center
* MMCF—one million cubic feet (measurement of natural gas)
* MMCFD—one million cubic feet per day
* MMGAL—one million gallons
* MMGAL/D—one million gallons per day
* MMS—Minerals Management Service (US)
* MMST—one million short tons
* MoC—Management of Change
* MODFLOW—model of groundwater flow
* MOU—Memorandum of Understanding
* MOX—mixed oxide fuel (nuclear)
* MPAN—Meter Point Administration Number
* MPG—Miles per gallon
* MRO—Midwest Reliability Organization (US)
* MSA—metropolitan statistical area
* MSHA—Mine Safety and Health Administration (US)
* msl—Mean sea level
* MSW—Municipal solid waste
* Mt—one million tons (ambiguous as to whether short tons or metric tons)
** —one Metric ton
* MTBE—methyl tertiary butyl ether
* MTEF—Medium Term Expenditure Framework
* MTEP—Midwest ISO Transmission Expansion Plan 2005 (US)
* Mtoe—One million tons of oil equivalent(EU)
* Muni—Municipality
* MVA—Megavolt amperes (one million volt amperes)
* MW—Megawatt (one million watts)
* MWE—megawatt electric
* MWh—Megawatt hour (one million watt hours)

## N

* NAAQS—National Ambient Air Quality Standards (US)
* NAESB—North American Energy Standards Board (formerly GISB)
* NAFTA—North American Free Trade Agreement
* NAICS—North American Industry Classification System
* NAP—National Renewable Energy Action Plan
* NARUC—National Association of Regulatory Utility Commissioners (US)
* NAS—United States National Academy of Sciences
* NASPI—North American Synchrophasor Initiative
* NASUCA—National Association of Utility Consumer Advocates(US)
* NATC—Non Recallable Available Transfer Capability
* NBS—National Bureau of Standards (US)
* NCD—Non coincidental Demand
* NCEP—National Council on Electricity Policy (US)
* NCSL—National Conference of State Legislatures (US)
* NEA—The National Energy Act of 1978 (US)
* NEB—National Energy Board (Canada)
* NEDRI—New England Distributed Resources Initiative (US)
* NEM—Net energy metering (US)
* NEPA—National Environmental Policy Act (US)
* NEPOOL—New England Power Pool
* NERC—North American Electric Reliability Council
* NGA—Natural Gas Act (US)
* NGAA—Natural Gasoline Association of America (US)
* NGL—natural gas liquids
* NGPA—Natural Gas Policy Act of 1978 (US)
* NGPL—Natural gas plant liquids
* NGPSA—Natural Gas Pipeline Safety Act of 1968 (US)
* NGSA—Natural Gas Supply Association (US)
* NGV—Natural gas vehicle
* NHPA—National Historic Preservation Act (US)
* NIETC—National Interest Electric Transmission Corridor (US)
* NITC—Normal Incremental Transfer Capability
* NIMBY—Not in my backyard regarding siting of energy generation and transmission infrastructure.
* NOAA—National Oceanic and Atmospheric Administration (US)
* NOC—National Oil Company
* NOI—Notice of Intent or Notice of Inquiry or Notice of Investigation
* NOPR—Notice of Proposed Rulemaking (US)
* NORDEL—association of Nordic electric system operators, comprising Denmark, Finland, Norway, Sweden
* NOx—nitrogen oxides
* NPCC—Northeast Power Coordinating Council (US)
* NPV—Net Present Value
* NRC—Nuclear Regulatory Commission (US)
* NRCS—National Resource Conservation Service (US)
* NRECA—National Association of Rural Electric Cooperatives (US)
* NREL—National Renewable Energy Laboratory (US)
* NREPA—National Resource and Environmental Protection Act (US)
* NRI—National Rivers Inventory (US)
* NRIS—Network Resource Interconnection Service (electricity)
* NSA—Noise sensitive area
* NTAC—Northwest Transmission Assessment Committee (US)
* NUG—Non Utility Generator
* NURE—national uranium resource evaluation (US)
* NYDER—New York Department of Environmental Resources
* NYISO—New York Independent System Operator, Inc. (US)
* NYMEX—New York Mercantile Exchange
* NYPSC—New York Public Service Commission
* NYSERDA—New York State Energy Research and Development Authority
* NIMYBY—Not In My BackYard

## O

* O&M—Operation and Maintenance Expenses
* O$_3$—Ozone
* OASIS—Open Access Same-Time Information System
* OATI—Open Access Technology International (US energy software company)
* OATT—Open Access Transmission Tariff (US)
* OCGT—Open Cycle Gas Turbine
* OCS—Outer Continental Shelf (oil and wind resources)
* OCSLA—Outer Continental Shelf Lands Act (oil)
* OECD—Organisation for Economic Co-operation and Development
* OEM—original equipment manufacturers
* OFO—Operational Flow Order
* OMP—Operation and Maintenance Plan
* Ontario—IESO Ontario Independent Electricity System Operator (Canada)
* OPEC—Organization of Petroleum-Exporting Countries (oil)
* OPRG—oxygenated fuels program reformulated gasoline (oil)
* OREC—ocean resource energy credits
* ORNL—Oak Ridge National Laboratory (U.S.) (nuclear)
* OSHA—U.S. Department of Labor Occupational Safety and Health Administration
* OTAG—Ozone Transport Assessment Group
* OTDF—Outage Transfer Distribution Factor
* OTEC—ocean thermal energy conversion (electricity)

## P

* P&ID—Piping & Instrumentation Diagram
* PA—Planning Authority
** —Programmatic Agreement
* PADD—Petroleum Administration for Defense Districts (US)
* PBR
** —pebble bed reactor (nuclear)
** —performance based rates (electricity)
** —Performance-based regulation
* PCB—polychlorinated biphenyl
* PCM—Project Cycle Management
* PCS—Power conversion system, electric power conversion. Plant Control System.
* PCT—Programmable Communicating Thermostat (electricity), Production Conformity Test
* PD—Preliminary Determination
* PDC—Phasor data concentrator. See description in phasor measurement unit article. (electricity)
* PDCI—Pacific Direct Current Intertie (US) (electricity)
* PDT—Pressure Differential Transmitter
* PERC—Passivated Emitter Rear Contact (type of PV cell)
* PEM—Proton Exchange Membrane
* PFC—perfluorocarbons
* PFD—Probability of Failure on Demand
* PG&E—Pacific Gas & Electric (US) (electricity)
* PGA—Purchased gas adjustment
* PHA—Production Handling Agreement, Process Hazard Analysis
* PHFFU—Plant held for future use
* PIDX—Petroleum Industry Data Exchange (oil)
* PIER—Public Interest Energy Research (CEC)
* PIFUA—Powerplant and Industrial Fuel Use Act of 1978
* PIU—Proven In Use
* PJM—PJM Interconnection, LLC, a regional transmission organization. (US) (electricity)
* PLC—Power line communication (electricity), Programmable Logic Controller
* PLMA—Peak Load Management Association (US) (electricity)
* PM—Particulate matter
* PM&E—Protection, mitigation and enhancement
* PMA—Power Marketing Administration or Fed. Power Marketing Agency (US) (electricity)
* PMU—Phasor measurement unit (electricity)
* PNNL—Pacific Northwest National Laboratory (DOE) (US)
* POD—Point of Delivery
* PoE—Power over Ethernet
* POLES—Prospective On Long Term Energy Systems
* POLR—Provider of last resort (electricity)
* PPA—Power Purchase Agreement (electricity)
* PPI—producer price index
* ppmv—Parts Per Million by Volume
* ppp—Purchasing power parity
* PPR—Potential peak reduction
* PREP—Pacific Regional Energy Programme
* PRESSEA—Promotion of Renewable Energy Sources in South East Asia (PRESSEA)
* Prim—Primary (electricity) nuclear, hydro, geothermal, wind, solar
* PSC—Public Service Commission
* PSD—Prevention of Significant Deterioration
* PSE—Puget Sound Energy (US) (electricity)
* PSoC—Partial State of Charge, operational mode of grid supporting batteries able to respond to both demand and excess production, see UltraBattery
* PTDF—Power Transfer Distribution Factor (electricity)
* PTP—Point to Point Transmission Service (electricity)
* PUC—Public utilities commission (electricity)
* PUD—Public utility district (electricity)
* PUHCA—Public Utility Holding Company Act of 1935 (US) (electricity)
* PURPA—Public Utility Regulatory Policies Act of 1978 (US) (electricity)
* PV—photovoltaic (solar)
* PVC—photovoltaic cell (solar)
* PVC—polyvinyl chloride
* PWR—pressurized water reactor (nuclear)
* PX—Power exchange

## Q

* QF—qualifying facility
* QRA—Quantitative Risk Assessment
* QSE—Qualifying scheduling entity
* QUAD—10$^{15}$ Btu (a quadrillion in the short scale)

## R

* R/P—Reserve on Production
** —Reserves to Production
* RA—Risk Assessment
* RAB—Regional Advisory Body (US)
* RAC—Refiners' acquisition cost
* RAP—Regulatory Assistance Project
* RAR—Reasonable assured resources
* RAS—Remedial Action Scheme
* RATC—Recallable Available Transmission Capability
* RBMK—Russian: Реактор Большой Мощности Канальный = "High Power Channel Type Reactor" (RU)
* RBOB—reformulated gasoline blendstock for oxygenate blending
* RC—Reliability Coordinator
* RCIS—Reliability Coordinator Information System
* RCRA—Resource Conservation and Recovery Act (US)
* RDF—refuse derived fuel (electricity)
* REA—Rural Electrification Administration (US)
* REC—Renewable energy credit (US)
* RECS—Residential Energy Consumption Survey (US)
* REEEP—Renewable Energy and Energy Efficiency Partnership
* RER—Renewable Energy Rider
* RES—Renewable energy source
* RET/EE—IAF Renewable Energy Technology & Energy Efficiency Investment Advisory Facility
* RF—Radio frequency
* RFA—Regulatory Flexibility Act (US)
* RFC—ReliabilityFirst Corporation (US) (electricity)
* RFG—reformulated gasoline (oil)
* RFI—Request for Interchange
* RFP—Request for proposals
* RGGI—Regional Greenhouse Gas Initiative
* RGS—Renewable Generating System
* RM—Rulemaking
* RMATS—Rocky Mountain Area Transmission Study (US) (electricity)
* RMR—Reliability Must Run (electricity)
* RMU—Removal Units
* ROA—Return of Assets (finance)
* ROE—Return of Equity (finance)
* ROFR—Right of First Refusal (finance)
* ROI—Return on Investment
* ROW—Right of Way
* RPM—Reliability Pricing Model. See explanation in electricity market#Deregulated market experience. (electricity)
* RPS—Renewable Portfolio Standards (US)
* RRO—Regional reliability organization (US)
* RSE—Revenue Stream Estimate (finance)
* RSE—relative standard error
* RTBM—Real-Time Balancing Market (electricity)
* RTEP—Regional transmission expansion plan
* RTG—Regional Transmission Group (US)
* RTO—Regional transmission organization (US)
* RTP—Real time Pricing
* RTU—Remote Terminal Unit
* RUS—Rural Utilities Service
* RVP—Reid vapor pressure

## S

* SCADA—Supervisory control and data acquisition a remote control and telemetry system used to monitor and control the electrical system
* SCE—Southern California Edison (US)
* SCE&G—South Carolina Electric & Gas (US)
* scf—Standard cubic foot
* SCO—Stranded Cost Obligation (finance)
* SCR—Special Case Resources (US- NYISO category)
* SCR—Selective Catalytic Reduction
* SDG&E—San Diego Gas & Electric (US)
* SEA—Strategic Environmental Assessment
* SEC—Securities and Exchange Commission (US)
* SEER—seasonal energy efficiency ratio
* SEFI—Sustainable Energy Finance Initiative
* SEIA—Sustainable Energy Industry Association
* Seams—Interconnections Seam Study
* SEPA—Smart Energy Power Alliance
* SERC—Southeastern Electric Reliability Council (US)
* SF—Safe Failure
* SF$_6$—sulfur hexafluoride
* SFC—Solid oxide fuel cell (transportation)
* SFEIS—Supplemental Final Environmental Impact Statement (US)
* SFF—Safe Failure Fraction
* SFV—Straight Fixed Variable
* SG—Spark-ignited Gas
* SGR—State game refuge (US)
* SHPO—State Historic Preservation Office (US)
* SI—International System of Units (Système international d'unités)
* SIC—Standard Industrial Classification
* SIF—Safety Instrumented Function
* SIL—Safety Integrity Level
* SIS—Safety Instrumented System
* SMES—Superconducting magnetic energy storage
* SMPs—Special Marketing Programs
* SNG—Synthetic Natural Gas or Substitute Natural Gas
* SO$_2$—Sulfur dioxide
* SoC—State of charge of rechargeable battery
* SoH—State of health of rechargeable battery
* SOL—System Operating Limit
* SPCC—Spill Prevention, Containment and Countermeasure Plan
** SPM—Synchronized phasor measurement- a WAMS network with synchrophasor sensors (PMUs). (electricity)
* SPP—Southwest Power Pool Inc., a regional transmission organization (US)
** —Statewide Pricing Pilot (US-California)
** —Small power producer (electricity)
* SPR—Strategic Petroleum Reserve (US)
* SPS—Special Protection System
* SR—Speculative resources For example, regarding uranium deposits. (nuclear)
* SRP—Salt River Agricultural Improvement & Power District (US) (electricity)
* SRS—Safety Requirement Specification
* SSG—WI PWG Seams Steering Group of Western Interconnection PlanningWork Group (US) (electricity)
* SSM—Synchronized system measurement-a WAMS with synchronous sensors in addition to PMUs. See Phasor networks.
* SSOV—Safety ShutOff Valve
* STEP—Southwest Transmission Expansion Plan group (US) (electricity)
* SVC—Static VAR compensator (electricity)
* SVEC—Shenandoah Valley Electric Cooperative
* SWAT—Southwest Area Transmission (US) (electricity)
* SWU—Separative work unit

## T

* TAME—Tertiary amyl methyl ether
* TAPS—Trans-Alaska Pipeline System (natural gas)
* TBA—tertiary butyl alcohol
* TBL—transmission business line (electricity)
* TBS—town border station
* Tcf—Trillion cubic feet (measurement)
* TCR—Transition cost recovery (mechanism)
* TDU—Transmission Dependent Utility (electricity)
* TEFRA—Tax Equity and Fiscal Responsibility Act of 1985
* TEN—Trans-European Networks (electricity)
* TLR—Transmission Line Loading Relief Procedures (electricity)
* TO—Transmission owner (electricity)
* toe—Ton of oil equivalent (EU)
* TOP—transmission operator (electricity)
* TOU—time of use (rate) (electricity)
* Transco—transmission company (US) (electricity)
** —Transcontinental Pipeline (US) (natural gas)
** —National Transmission Corporation (Philippines)
* TRM—Transmission reliability margin (electricity)
* TS—Two-stage
* TSO—Transmission system operator) (electricity)
* TSR—Transmission service request (electricity)
* TTC—Total transfer capability (electricity)
* TVA—Tennessee Valley Authority (US) (electricity)
* TW—terawatt (one trillion watts) (measurement)
* TWH—terawatt-hour (one trillion watt hours)
* T&D—Transmission and distribution

## U

* U.S.C.—United States Code
* U$_3$O$_8$—triuranium octaoxide (nuclear)
* UAE—United Arab Emirates (oil)
* UCAP—Unforced Capacity (electricity)
* UCTE—Union for the Coordination of the Transport of Electricity, the power transmission system of continental Europe
* UF$_6$—uranium hexafluoride (nuclear)
* UFLS—Under frequency load shedding (electricity)
* UHVAC—ultra-high-voltage alternating current (electricity)
* UHVDC—ultra-high-voltage direct current (electricity)
* ULCC—Ultra Large Crude Carrier (oil)
* UMTRA—Uranium Mill Tailings Radiation Control Act of 1978 (US)
* UNCCD—United Nations Convention to Combat Desertification
* UNDESA—UN Department of Economic and Social Affairs
* UNDP—United Nations Development Programme
* UNDP—United Nations Development Programme
* UNECE—United Nations Economic Commission for Europe
* UNEP—United Nations Environment Programme
* UNFCCC—United Nations Framework Convention on Climate Change
* UO$_2$—uranium dioxide (nuclear)
* UO$_3$—uranium trioxide (nuclear)
* UO$_4$—uranyl peroxide (nuclear)
* UOX—uranium oxide (nuclear)
* URR—Ultimate Recoverable Resources
* USBR—United States Bureau of Reclamation
* USCE—United States Army Corps of Engineers
* US DOE—United States Department of Energy
* USGS—United States Geological Survey
* UVLS—under voltage load shedding (electricity)

## V

* V—Volt (measurement)
* VA—Volt-ampere (measurement)
* var—Volt-ampere reactive (measurement)
* VAWT—vertical axis wind turbine (wind)
* VIN—vehicle identification number (US) (transportation)
* VLCC—very large crude carrier (oil)
* VMT—vehicle miles traveled (transportation)
* VOC—volatile organic compound
* VPP—Variable peak pricing (electricity)
* VSA—Voltage stability analysis

## W

* W—Watt
* WACOG—weighted average cost of gas
* WAMS—Wide area measurement system, also Wide area monitoring system - see description in phasor measurement unit article. (electricity)
* WCMC—World Conservation Monitoring Centre
* WCRE—World Commission on Renewable Energy
* WEA—World Energy Assessment
* WEC—World Energy Council
* WECC—Western Electricity Coordinating Council (US)
* WEI—Western Electric Institute (US)
* WEEA—World Energy Efficiency Organization
* WH—watthour (measurement)
* WHO—World Health Organization
* WIRAB—Western Interconnection Regional Advisory Body (US)
* WRI—World Resources Institute
* WSCC—Western Systems Coordinating Council (US)
* WSPP—Western Systems Power Pool (US)
* WSSD—World Summit on Sustainable Development
* WTG—Wind turbine generator (wind)
* WTI—West Texas Intermediate (US)
* WTP—Willingness to pay
* WY—Water Year (measurement)

## Appendix: Residential energy acronyms

The following table lists a number of terms that are used in the United States for residential energy audits.
* AFUE—annual fuel utilization efficiency
* BTL—building tightness limit (building tightness)
* CDH—cooling degree hours (climate)
* CFL—compact fluorescent light
* COP—coefficient of performance
* CRI—color rendering index
* EEM—Energy Efficient Mortgage
* EER—energy efficiency ratio
* EF—energy factor (clothes washers)
* EIM—Energy Improvement Mortgage
* ERV—energy-recovery ventilator
* HDD—heating degree day
* HHI—home heating index
* HID—high-intensity discharge
* HRV—heat-recovery ventilator
* HSPF—heating seasonal performance factor
* HVI—Home Ventilating Institute
* IECC—International Energy Conservation Code
* K-value—thermal conductance
* Low-e—low emissivity
* LEED—Leadership in Energy and Environmental Design, standard for Green Building design
* MEF—modified energy factor (clothes washers)
* MINHERS—Mortgage Industry National Home Energy Rating Systems Standards
* MVG—minimum ventilation guideline (building tightness)
* MVL—minimum ventilation level (building tightness)
* NAECA—National Appliance Energy Conservation Act
* ODS—oxygen depletion sensor
* RESNET—Residential energy services network
* R-value—thermal resistance
* SC—shading coefficient (windows)
* SEER—seasonal E efficiency ratio
* SHGC—solar heat gain coefficient
* SIR—savings-to-investment ratio (energy conservation investments)
* SLA—Specific leakage area
* SPB—Simple Payback (energy conservation investments)
* SSE—steady-state efficiency
* U-value—thermal transmittance (also called U-factor)
* WF—water factor (clothes washers)