A

AC – Alternating Current

Act 129 (PA) – Act 129 of 2008 provides Pennsylvania electric utility consumers opportunities to take energy efficiency and conservation to the next level. The General Assembly enacted Act 129 to require Pennsylvania’s seven largest electric distribution companies (EDCs) to develop energy efficiency and conservation plans (EE&C) and adopt other methods of reducing the amount of electricity consumed by customers.

AMI – Advanced Metering Infrastructure. Smart metering systems that automatically collect and transmit electricity, gas, or water consumption data at regular intervals.

Annual Energy Cost Savings – The estimated reduction in utility costs achieved through an energy efficiency, renewable energy, or operational improvement project over a one-year period.

ASHP – Air Source Heat Pump. A system that transfers heat between a building and the outdoor air to provide heating and cooling.

ASHRAE – American Society of Heating, Refrigeration & Air Conditioning Engineers.

Avoided Cost – The cost a utility would incur to generate its next unit of energy or power. Avoided cost rates have historically been used as the power purchase price utilities offer Qualifying Facilities.

B

BCF – Billion Cubic Feet.

BEMS – Building Energy Management System. Software and controls used to monitor, automate, and optimize building energy performance.

BEPS – Building Energy Performance Standards. Regulations requiring existing buildings to meet specified energy efficiency or emissions targets over time.

BESS – Battery Energy Storage System. A rechargeable energy storage system that stores electricity for later use during periods of high demand, outages, or peak pricing.

Behind-the-Meter (BTM) – Energy generation, storage, or management equipment located on the customer side of the utility meter.

Benchmarking – The process of measuring and comparing a building’s energy performance against historical performance or similar facilities.

Building Electrification – The replacement of fossil-fuel-powered equipment with electric technologies such as heat pumps, electric boilers, and induction cooking systems.

Building Performance Standard (BPS) – Regulations establishing energy or emissions performance targets for existing buildings.

BTU – The British Thermal Unit (BTU or Btu) is a unit of heat energy used in the U.S. A Btu is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. In the energy world, energy content is typically discussed in MMBtu.

C

C&I – Commercial and Industrial. A broad classification of non-residential facilities including office buildings, schools, hospitals, manufacturers, warehouses, and institutions.

Capacity – The amount of power that a generator can produce at a point in time, usually reported in MW.

Capacity Factor – Ratio of the actual output of a power plant over a period of time to its output if it had operated at full capacity during that period.

Carbon Footprint – The total greenhouse gas emissions associated with an organization, facility, process, or activity.

Carbon Neutral – Achieving net-zero carbon emissions by reducing emissions and offsetting any remaining emissions.

Cash Flow Positive – A project that generates annual savings greater than its financing or operating costs.

CHP – Combined Heat and Power. Simultaneous production of electricity and useful thermal energy from a single fuel source. Also known as cogeneration.

CNG – Compressed Natural Gas.

Cogeneration – The sequential production and use of heat and power from a power plant.

CO₂e – Carbon Dioxide Equivalent. A standard unit used to compare the climate impacts of different greenhouse gases.

Community Solar – A solar project that allows multiple customers to subscribe and receive utility bill credits without hosting solar panels on their own property.

Compliance Pathway – A documented strategy used to meet building performance standard or benchmarking requirements.

Co-op – A cooperative electric utility, usually based in rural areas. Co-ops are owned by their members.

CSP – Curtailment Service Provider.

CT – Current Transformer.

Current – (Ampere, Amp) (I) = Current is the amount of electricity flowing in a circuit past a given point.

D

DAS – Data Acquisition System. Hardware and software used to collect, store, and manage energy consumption and equipment performance data.

DC – Direct Current.

DC Fast Charging – High-speed electric vehicle charging equipment that uses direct current power to rapidly charge EV batteries.

Decarbonization – The reduction or elimination of greenhouse gas emissions associated with energy consumption and operations.

Demand – Electric demand (load) is the amount of electricity required at an instantaneous point in time.

Demand Charge – A utility charge based on the maximum amount of electric demand a customer places on the grid during a billing period.

Demand Flexibility – The ability to modify energy consumption patterns in response to energy prices, grid conditions, or utility requests.

Demand Side Management (DSM) – Utility programs designed to reduce customer demand (kW).

DER – Distributed Energy Resource. Small-scale energy assets located near the point of consumption, including solar arrays, battery storage systems, and controllable loads.

DERMS – Distributed Energy Resource Management System. Software used to manage and optimize distributed energy resources.

DG – Distributed Generation. Small-scale power generation systems typically located on a customer site.

Distribution System – The poles, wires, transformers, and related infrastructure used to deliver electricity from the transmission system to customers.

DOE – Department of Energy.

DR – Demand Response.

Direct Pay – A federal incentive mechanism allowing certain tax-exempt entities to receive clean energy tax credits as direct payments.

DSM – Demand Side Management.

DSR – Demand-Side Response.

Dth – Dekatherm (equivalent to 1 MMBtu).

E

Economic Useful Life (EUL) – The estimated period during which equipment continues to deliver energy savings or operational benefits.

EDC – Electric Distribution Company.

EDI – Electronic Data Interchange.

EEI – Edison Electric Institute.

EER – Energy Efficiency Ratio.

EGS – Electric Generation Supplier.

EHV – Extra High Voltage.

Electrical Energy – The generation or use of electric power over a period of time, often expressed in kWh, MWh, or GWh.

Electrification – The replacement of fossil-fuel-powered equipment with electric technologies.

EMF – Electric Magnetic Fields.

EMS – Energy Management System.

Energy – The ability to do work (Joules, Btu, or kWh).

Energy Burden – The percentage of income or organizational budget spent on energy costs.

EnergyCAP – A Utility Bill Management (UBM) software platform used for utility bill processing, auditing, reporting, benchmarking, budgeting, and sustainability tracking.

Energy Information System (EIS) – Software used to collect, analyze, and visualize building energy performance data.

Energy Resilience – The ability of a facility to prepare for, withstand, and recover from utility outages or energy disruptions.

ENERGY STAR Benchmarking – Tracking and comparing building energy performance using the EPA’s ENERGY STAR Portfolio Manager platform.

EPA – Environmental Protection Agency.

EPAct – National Energy Policy Act of 1992.

EPAct – Energy Policy Act of 2005.

EPRI – Electric Power Research Institute.

ESCO – Energy Service Company.

ESG – Environmental, Social, and Governance. A framework used to evaluate sustainability and corporate responsibility performance.

EV – Electric Vehicle.

EVSE – Electric Vehicle Supply Equipment, commonly known as EV charging stations.

EUI – Energy Use Intensity. A building performance metric that measures annual energy consumption per square foot.

F

Federally Owned Utility – Non-profit entity owned by the federal government that primarily sells bulk power to other power entities. The Tennessee Valley Authority (TVA) is an example.

FERC – Federal Energy Regulatory Commission.

FPPL – Forecast Period Peak Load.

FPR – Forecasted Pool Requirement.

Front-of-the-Meter (FTM) – Energy generation or storage resources located on the utility side of the electric meter.

Fuel Switching – Replacing one fuel source with another for economic, operational, or environmental reasons.

G

GEB – Grid Interactive Efficient Building. A building that uses advanced controls, automation, and flexible energy loads to optimize energy consumption while supporting electric grid reliability.

Genco – Generation Company.

Generating Station – A power plant. Can be owned by utilities, independent power producers, municipalities, cooperatives, or private entities.

Generation – The process of producing electric energy by transforming other forms of energy (coal, hydro, natural gas, solar, wind, etc.) into electricity.

Generation & Transmission Co-op (G&T) – Bulk power producer and transmitter of electricity. Typically serves distribution cooperatives and municipal utilities.

GHG – Greenhouse Gas. Atmospheric gases such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) that contribute to climate change.

GHG Inventory – A systematic accounting of greenhouse gas emissions associated with an organization, facility, portfolio, or operation.

Green Power – Electricity produced from renewable or environmentally preferable resources such as solar, wind, biomass, geothermal, and certain hydroelectric facilities.

Green Pricing – A utility-based program that allows customers to voluntarily purchase renewable energy at a premium.

Grid – A network of transmission and distribution lines used to deliver electricity.

Ground Source Heat Pump (GSHP) – A heating and cooling system that transfers heat between a building and the earth using underground piping. Also known as a geothermal heat pump.

GRT – Gross Receipts Tax.

GW – Gigawatt = 1 billion watts = 1,000 MW.

H

Heat Pump – A high-efficiency electric system that transfers heat rather than generating it directly, providing both heating and cooling.

Heat Pump Water Heater (HPWH) – An electric water heater that uses heat pump technology to transfer heat instead of generating heat directly, significantly reducing energy consumption.

Heat Rate – (Btu/kWh) A measure of the efficiency of a power plant. The lower the heat rate, the more efficient the plant.

HVAC – Heating, Ventilation, and Air Conditioning.

HVDC – High Voltage Direct Current. A transmission technology used to move large amounts of electricity over long distances with minimal losses.

Hz – Hertz.

I

ICAP – Installed Capacity Obligation.

IEEE – Institute of Electrical and Electronics Engineers, Inc.

Induction Cooking – A cooking technology that uses electromagnetic energy to directly heat cookware, offering high efficiency and precise temperature control.

Inflation Reduction Act (IRA) – Federal legislation enacted in 2022 that expanded incentives, grants, tax credits, and financing opportunities for energy efficiency, clean energy, electrification, and emissions reduction projects.

Interval Data – Utility usage data collected at consistent time intervals, typically every 5, 15, 30, or 60 minutes, allowing detailed consumption analysis.

Internal Rate of Return (IRR) – A financial metric used to evaluate investment opportunities based on the discount rate at which net present value equals zero.

Investment Tax Credit (ITC) – A federal tax incentive allowing eligible renewable energy and energy storage projects to deduct a percentage of project costs from tax liability.

IOU – Investor Owned Utility (e.g., PPL Electric Utilities). Owned by investors or stockholders and regulated by state and federal authorities.

IPP – Independent Power Producer. A power generation facility owned by an entity other than a traditional utility.

ISO – Independent System Operator. A FERC-regulated control area operator responsible for managing transmission system reliability and market operations.

J

(No common energy industry terms currently recommended.)

K

kV – Kilovolt.

KVA – Kilovolt-Ampere. Commonly used as a transformer size rating.

KVAR – Kilovolt-Ampere Reactive.

kW – Kilowatt = 1,000 watts.

kWh – Kilowatt-hour. The basic unit of electrical energy equal to one kilowatt of power used for one hour.

L

LA – Load Aggregator.

LCOE – Levelized Cost of Energy. The total lifetime cost of an energy project divided by the total expected energy production over its useful life.

LDC – Local Distribution Company.

Level 1 Charging – Electric vehicle charging using a standard 120-volt electrical outlet.

Level 2 Charging – Electric vehicle charging using a 208- or 240-volt electrical connection, providing significantly faster charging than Level 1.

Lifecycle Cost Analysis – An economic evaluation method that assesses all costs associated with equipment or projects over their expected useful life.

Line Losses – Energy losses resulting from transmitting electricity across power lines.

Load – The amount of electric power required to meet customer demand at a given time, expressed in kilowatts (kW) or megawatts (MW).

Load Factor – The ratio of electrical demand to energy usage over time. Higher load factors generally indicate more efficient use of electric infrastructure.

Load Profile – The pattern of a facility’s electricity consumption over a defined period, often displayed hourly, daily, monthly, or annually.

Load Shedding – The intentional reduction of electrical demand during periods of high energy prices, grid stress, or utility request.

Locational Marginal Price (LMP) – The price assessed for congestion and transmission losses at a specific node on the electric grid.

LMP – Locational Marginal Pricing.

LNG – Liquefied Natural Gas.

LSE – Load Serving Entity.

LTC – Load Tap Changing.

M

Mcf – Thousand cubic feet of natural gas. Roughly equivalent to 1 MMBtu.

Measurement, Reporting, and Verification (MRV) – The process of quantifying, documenting, and validating energy savings or emissions reductions resulting from a project or operational improvement.

Meter Data Management (MDM) – Software and processes used to collect, validate, store, and analyze utility meter data.

Microgrid – A localized energy system consisting of generation, storage, and loads that can operate independently from the utility grid during outages or other disruptions.

MMBtu – One Million British Thermal Units.

MOC – Market Operations Center.

MRV – Measurement, Reporting, and Verification.

Muni – A municipality-owned utility (e.g., Ephrata Borough in Lancaster County, Pennsylvania).

MVAR – Mega Volt-Amperes Reactive.

MW – Megawatt = 1 million watts = 1,000 kW.

MWd – Megawatt-Day.

N

NEMA – National Electrical Manufacturers Association.

NEPA – National Energy Policy Act of 1992.

NERC – North American Electric Reliability Corporation. The organization responsible for developing and enforcing reliability standards for North America’s bulk electric systems.

Net Metering – A policy allowing customers with renewable energy systems, such as solar PV, to receive credit for excess electricity exported to the electric grid.

Net Zero Carbon – Achieving net-zero greenhouse gas emissions by reducing emissions as much as possible and offsetting any remaining emissions.

Net Zero Energy Building – A building that produces as much energy annually as it consumes.

NITS – Network Integrated Transmission Service.

Nodal Market – A method of assessing congestion costs based on specific transmission nodes rather than broad utility zones.

Non-Wires Alternative (NWA) – A project or solution that avoids or delays traditional grid infrastructure upgrades through energy efficiency, distributed generation, storage, or demand response.

NPV – Net Present Value. A financial metric used to evaluate investments based on the present value of future cash flows.

NRC – Nuclear Regulatory Commission.

NUG – Non-Utility Generator.

NYMEX – New York Mercantile Exchange.

O

O&M – Operations and Maintenance Expenses.

OATT – Open Access Transmission Tariff.

OCB – Oil Circuit Breaker.

OSHA – Occupational Safety and Health Administration.

P

PCB – Polychlorinated Biphenyls.

Peak Demand – The highest level of electric demand recorded during a specific time period.

Peak Load – The maximum expected load for a given period of time.

Peak Shaving – Strategies used to reduce a facility’s maximum electrical demand in order to lower demand charges and reduce grid stress.

PJM – PJM Interconnection, LLC, the regional transmission organization responsible for coordinating wholesale electricity markets and grid reliability throughout much of the Mid-Atlantic region.

POLR – Provider of Last Resort. A company designated to provide electric service when a customer does not have an active competitive supplier.

Portfolio Manager – The U.S. EPA’s ENERGY STAR benchmarking platform used to track, compare, and report building energy and water performance.

Power – (Watt, W) (P) = Current × Voltage (P = I × V). Power is the instantaneous rate at which work is performed.

Power Purchase Agreement (PPA) – A contractual arrangement in which a third party owns and operates an energy system and sells the generated electricity to a customer.

Prevailing Wage and Apprenticeship Requirements – Federal labor requirements that may increase clean energy tax credits when qualifying wage and apprenticeship standards are met.

Production Tax Credit (PTC) – A federal tax incentive based on the amount of renewable electricity produced by eligible projects.

PT – Potential Transformer.

PTC – Price to Compare. The default electric supply rate against which competitive supplier pricing is typically evaluated.

PUC – Public Utility Commission. In Pennsylvania, the Pennsylvania Public Utility Commission regulates electric, natural gas, telecommunications, and water utilities.

PURPA – Public Utility Regulatory Policies Act of 1978.

PV – Photovoltaic. Technology that converts sunlight directly into electricity.

Q

QF – Qualifying Facility. A class of power producer established under PURPA that includes certain small renewable generators and cogeneration facilities.

R

REC – Renewable Energy Certificate. A tradable environmental commodity representing proof that one megawatt-hour (MWh) of electricity was generated from an eligible renewable energy source.

Renewable Natural Gas (RNG) – Pipeline-quality gas produced from renewable feedstocks such as landfills, wastewater treatment plants, food waste digesters, and agricultural operations.

Request for Proposal (RFP) – A formal solicitation issued to vendors requesting pricing and technical responses for products or services.

Resilience – The ability of a facility, organization, or energy system to withstand and recover from disruptions such as utility outages, extreme weather, or fuel supply interruptions.

Resistance – (R, Ohms) A measure of the degree to which an object opposes electric current flow. Resistance is calculated as R = V/I.

Revenue Grade Metering – Utility-grade metering equipment that meets established accuracy standards for billing and financial transactions.

RFP – Request for Proposal.

RMR – Reliability Must Run. A generating facility required by a regional transmission organization to continue operating to maintain electric system reliability.

RNG – Renewable Natural Gas.

ROI – Return on Investment.

RPM – Reliability Pricing Model. PJM’s capacity market construct used to ensure adequate future generation resources.

RPS – Renewable Portfolio Standard. Regulations requiring a specified percentage of electricity generation to come from renewable resources.

RTO – Regional Transmission Organization.

RTP – Real-Time Pricing. Electricity pricing that varies based on wholesale market conditions.

S

Scope 1 Emissions – Direct greenhouse gas emissions from sources owned or controlled by an organization, including boilers, furnaces, generators, and company vehicles.

Scope 2 Emissions – Indirect greenhouse gas emissions associated with purchased electricity, steam, heating, or cooling.

Scope 3 Emissions – Other indirect emissions occurring throughout an organization’s value chain, including employee commuting, business travel, purchased goods, transportation, and waste disposal.

SEER – Seasonal Energy Efficiency Ratio.

Simple Payback – The amount of time required for project savings to recover the initial investment cost.

Site EUI – Site Energy Use Intensity. A measure of total energy consumed at a building, expressed per square foot of floor area.

Slamming – The unauthorized transfer of a customer’s electric service by a retail electric provider.

SIC – Standard Industrial Classification.

Smart Building – A building utilizing sensors, automation systems, analytics, and controls to improve efficiency, occupant comfort, and operational performance.

Smart Meter – An advanced utility meter capable of automatically communicating usage information between the utility and customer.

Solar PV – Solar photovoltaic technology that converts sunlight directly into electricity.

Source EUI – Source Energy Use Intensity. A building performance metric that accounts for losses associated with the generation, transmission, and distribution of energy.

Sustainability Reporting – The process of measuring and disclosing environmental, social, governance, energy, emissions, and sustainability performance metrics.

T

Therm – A unit used to measure natural gas consumption equal to 100,000 Btu. Ten therms equals approximately 1 MMBtu.

TOU – Time-of-Use. A utility rate structure where the price of electricity varies depending on the time of day.

Transmission System – An interconnected network of power lines and equipment used to move bulk electricity from generation sources to substations and local distribution systems. Typically operates at 69 kV and higher.

TRM – Transmission Reserve Margin or Transmission Reliability Margin.

U

UBM – Utility Bill Management. The process of collecting, validating, auditing, allocating, budgeting, analyzing, and reporting utility billing data.

UCAP – Unforced Capacity. A generator’s capacity adjusted to account for expected operating performance and availability.

Unbundling – The separation of traditional electric utility functions into generation, transmission, distribution, and retail supply entities to encourage competition.

Utility Bill Audit – A detailed review of utility invoices to identify billing errors, rate opportunities, meter issues, tax discrepancies, and operational anomalies.

V

VAR – Volt-Ampere Reactive.

VFD – Variable Frequency Drive. An electronic device that controls motor speed and reduces energy consumption by matching motor output to actual operating requirements.

Virtual Power Plant (VPP) – A network of distributed energy resources such as battery storage, solar generation, demand response, and controllable loads that operate collectively as a single power resource.

Voltage – (Volts) (V) The difference of electrical potential across two points. Voltage represents the potential energy that causes electricity to flow through a circuit.

W

W – Watt. The basic unit of electrical power.

Weather Normalization – The adjustment of energy consumption data to account for variations in weather conditions, enabling more accurate year-over-year performance comparisons.

X

(No common energy industry terms currently recommended.)

Y

(No common energy industry terms currently recommended.)

Z

Zero Net Energy (ZNE) – A building that produces as much energy annually as it consumes through a combination of efficiency measures and on-site renewable energy generation.

Zero Emissions Building – A building designed and operated to eliminate direct greenhouse gas emissions associated with heating, cooling, water heating, and building operations.

*Some of these definitions are courtesy of U.S. Department of Energy, Wikipedia and PJM