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


Advanced Metering Infrastructure (AMI) - An integrated system of smart meters, communications networks, and data management systems that enables two-way communication between utilities and customers.

Alternative Fuel Vehicles - This includes technologies and products that are used in vehicles that run on alternative fuels. This also includes the conversion of traditional fuel vehicles to run on alternative fuels. Find out more.

Audit (Energy Audit) - An assessment of a home’s energy use.

Automatic Meter Reading (AMR) - A system of electric meters from which data can be gathered on a monthly basis without requiring a physical reading of the meter.

Avoided Cost - The incremental cost that a utility avoids by purchasing power from a qualifying facility (QF) rather than generating power itself or purchasing it from another source.

Avoided Cost Rates - The rates paid by a public utility to a qualifying facility (QF) for the purchase of electricity, based on the avoided cost of the public utility and as approved by the NC Utilities Commission (see, NCUC).


Balancing Authority - An entity that works to ensure that electricity supply and demand are met to maintain the safety of the grid. There are 66 balancing authorities in the United States, including all the Regional Transmission Organizations (see, RTO).

Bioenergy - This includes both Agricultural/Forestry Bioenergy (such as animal waste and plant-based sources) and Municipal Bioenergy (such as municipal wastewater and municipal solid waste. Find out more.

Blower Door - A fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. This test determines the air infiltration rate of a building.


Capital Structure - The relative shares of a utility’s capital that come from debt and equity. Since equity is more expensive than debt, a utility’s capital structure can impact its rate of return.

Carolina Power & Light (CP&L) - The predecessor company to Progress Energy.

Certificate of Public Convenience and Necessity (CPCN) - A certificate that must be obtained from the NCUC prior to construction of a new electric generating facility with a capacity of 2-80 MW.

Chapter 62 - See, Public Utilities Act.

Co-Op - See, Electric Membership Corporation.

Code of Federal Regulations (CFR) - Rules and regulations adopted by the federal government.

Combined Cycle (CC) - A natural gas generator where a combustion turbine (CT) is paired with a steam turbine for greater efficiency.

Combined Heat and Power (CHP) - The use of a heat engine or power station to generate electricity and useful heat at the same time.

Combustion Turbine (CT) - A natural gas generator that heats air to spin an electric generator.

Community Solar - A solar power plant whose electricity is shared by subscribers who may not necessarily be located near the plant itself. 

Cooperative - See, Electric Membership Corporation.

Competitive Procurement of Renewable Energy (CPRE) - Prior to the passage of HB589, public utilities were required to purchase renewable energy at an “avoided cost” rate set by the NCUC. HB589 set up a competitive bidding process for renewable energy (CPRE) for larger energy producers including Duke Energy. These large producers must submit an RFP for a total of 2,660 MW over a 45-month period.

Cost of Service Regulation - Refers to the regulated tariff that covers justified costs of an electric utility’s operation (costs that are necessary and unavoidable) to provide the regulated service at a predefined level of quality.

Curtailment - Reduction in the output of a generating unit from what it could otherwise produce given available resources.


Deferral Accounting - An accounting procedure whereby an asset or liability is carried forward until a future date.

Demand - The maximum amount of energy that is being consumed at a given time.

Demand Charge - An additional charge to an energy bill based on the maximum amount of power drawn over a given period of time during a billing period.

Demand Side Management (DSM) - Activities, programs, or initiatives undertaken by an electric power supplier or its customers to shift the timing of electricity use from peak to non-peak demand periods.

Demand Response - An option for customers to reduce their demand charge by lowering energy use at peak periods.

Department of Energy (DOE) - The United States federal government agency concerning energy policy and safety regarding nuclear material.

Department of Environment and Natural Resources (DENR) - Predecessor of the Department of Environmental Quality.

Department of Environment, Health, and Natural Resources (DEHNR) - Predecessor of the Department of Environment and Natural Resources.

Department of Environmental Quality (DEQ) - Agency for the protection of North Carolina’s environmental resources.

DHHS - Department of Health & Human Services

Differential Revenue Requirement (DRR) - The differential revenue requirement, or DRR, calculates the difference in the utility’s overall generation cost with and without a Qualifying Facility capacity.

Distributed Energy Resources (DER) - Small generation resources that are deployed across the distribution grid, typically close to load and behind the meter, to provide value to the grid and individual customers.

Distributed Generation (DG) - Electrical generation performed by distributed energy resources.

Distribution - Refers to the last stage of electric power delivery carrying electricity from the transmission system to individual customers.

Docket - The method of organizing proceedings before the Federal Energy Regulatory Commission (FERC) and the NCUC.

Dominion Energy North Carolina (DENC) - Investor-owned utility serving northeastern North Carolina. An operating division of Virginia Electric and Power Company and a subsidiary of Dominion Resources.

Dominion North Carolina Power (DNCP) - Predecessor of Dominion Energy North Carolina.

DSM/EE Rider - An annual rider to the rates of a public utility to recover costs associated with their demand-side management and energy efficiency measures. See, N.C.G.S. § 62-133.9.

Duke Energy Carolinas (DEC) - The operating utility serving much of the western portion of North Carolina. A subsidiary of Duke Energy Corporation.

Duke Energy Corporation (Duke) - A holding company based in Charlotte, NC that owns several public utilities operating in various states as well as unregulated subsidiaries. The parent company of Duke Energy Carolinas, Duke Energy Progress, and Duke Energy Renewables.

Duke Energy Progress (DEP) - The operating utility serving much of the eastern portion of North Carolina and the Asheville area. A subsidiary of Duke Energy Corporation.

Duke Energy Renewables - An unregulated business that provides renewable energy products and services nationwide. A wholly-owned subsidiary of Duke Energy Corporation.

Duke Power - Predecessor of Duke Energy Carolinas.


Electric Membership Corporation (EMC) - Member-owned cooperative electric utilities that supply primarily rural customers in North Carolina.

ElectriCities - A trade organization consisting of North Carolina Eastern Municipal Power Agency and North Carolina Municipal Power Agency Number 1 (see, NCMPA1).

Energy Burden - Refers to the percentage of total household income spent on energy bills. A household with high energy burden pays a disproportionate amount of their monthly budget on energy costs.

Energy Charge - The rate power suppliers charge customers specifically for their kWh electricity usage over a billing period.

Energy Efficiency (EE) - This includes technologies (including passive solar), products, and services that reduce the amount of energy required for buildings, processes, or tasks. Find out more.

Energy Information Administration (EIA) - An agency within the United States Department of Energy (see, DoE) that collects data on all things related to energy, from gas prices to the capacity factors of power plants.

Energy Policy Council (EPC) - The North Carolina Energy Policy Council advises the governor and General Assembly on legislation and rulemaking that addresses domestic energy exploration, protects the environment, and encourages economic development. Read more.

Energy Storage - This includes technologies and products that are used to store energy for later use. Find out more.

Electric Measurement and Verification (EM&V) - See, Measurement & Verification.

Expert Witness - A person who is permitted to testify at a trial because of special knowledge or proficiency in a particular field that is relevant to the case. In our case, expert witnesses typically provide testimony for proceedings at the North Carolina Utilities Commission.


Federal Energy Regulatory Commission (FERC) - An independent government agency designed to protect the public and energy customers, regulating interstate transmission of natural gas, oil, and electricity; the wholesale sale of electricity, licensing hydropower projects, approving natural gas pipelines and overall reliability of the electric grid.

Fixed Charge - This is a charge that some customers have to pay before their energy meter starts running.

Franchise - A grant of authority from the North Carolina Utilities Commission for a business to act as a public utility, which may include the grant of exclusive territory.

Fuel Rider - An annual rider to the rates of a public utility to recover costs of fuel and fuel-related costs. See, N.C.G.S. § 62-133.2.


General Rate Case - Proceedings used to address the costs of operating and maintaining the utility system and the allocation of those costs among customer classes.

Generation Capacity - Refers to the maximum amount of electricity (as measured in megawatts or MW) a generator can produce when running at full blast.

Geothermal/Ground Source Heat Pumps- This includes both Geothermal Energy and Ground Source Heat Pump (GSHP) technologies. Geothermal Energy technology utilizes the thermal energy (heat) stored in the Earth to generate electricity, while GSHPs are central heating and cooling systems that increase efficiency by transferring heat to or from the ground or a body of water. Find out more.

Green Source Advantage - A program that is part of HB589 that provides military installations, the University of North Carolina institutions, and large commercial customers the option to secure significant amounts of renewable energy to satisfy their clean energy goals. Read More.

Grid - The layout of an electrical distribution system; a system of interconnected power lines and generators.


Helping Home Fund - A program administered by the North Carolina Community Action Association and offered through a network of community action agencies that serve households in Duke’s North Carolina service territories. The Helping Home Fund program delivers weatherization services, heating and cooling system repairs, appliance replacements and critical health and safety repairs at no cost to households at or below 200 percent of federal poverty guidelines.

Hosting Capacity Maps - A map or analytical tool that tells developers of distributed generation the amount of capacity that a distribution feeder can accommodate without extensive upgrades.

House Bill 589 (HB589) - The “Competitive Energy Solutions for NC” passed in 2017 and signed by Governor Cooper. Read more here.

Hydropower - This includes technologies or devices that harness the force of falling or flowing water, including marine waves, for useful purposes such as generating electricity or creating mechanical force. Find out more.


Incumbent Utility - The utility with the territorial rights to a particular location.

Independent Power Producer (IPP) - An entity, which is not a public utility, but which owns facilities to generate electric power for sale to utilities and end users.

Integrated Distribution Planning (IDP) - A process that utilities undergo to map out their existing systems through a detailed engineering assessment in order to identify infrastructure changes that may be needed to achieve grid modernization goals.

Integrated Resource Plan (IRP) - A utility plan for meeting forecasted annual peak and energy demand, with some reserve margin, over a specified future period.

Integrated Systems Operation Planning - Duke Energy’s planning framework that combines generation, transmission, and distribution planning. For more information, see Duke Energy’s website here.

Integrated Volt Var Control - A smart grid technology that optimizes voltage and reactive power to reduce peak power demands.

Interconnection (IX) - The process by which an independent power producer connects to the electric grid operated by an incumbent utility.

Interconnection Agreement (IA) - Two or more utilities agreeing to connect their power grids.

Interconnection Queue - The order in which qualifying facilities are interconnected to the electric grid by incumbent utilities.

Interconnection Standard - Defines how utilities (such as solar, wind, etc.) can physically connect to the grid.

Investor-Owned Utility (IOU) - A publicly-traded electric public utility. The investor-owned utilities operating in North Carolina are Duke Energy Carolinas, Duke Energy Progress, and Dominion North Carolina Power.


Kilowatt (kW) - 1,000 watts, where a watt is a unit of electrical power calculated in Joules per second.

Kilowatt Hour (kWh) - A unit of energy that is typically used to measure the amount of electricity consumed by a customer over a billing periodOne thousand watt-hours equal 1 kWh.


Legally Enforceable Obligation (LEO) - An obligation of a utility to purchase electricity or capacity from a qualifying facility under PURPA established by the states, even in the absence of a contract. In North Carolina, a legally enforceable obligation arises when a qualifying facility has obtained a certificate of public convenience and necessity and has committed to sell its generation to the utility.

Lessee - The customer who is leasing a distributed energy resource (see, HB589).

Lessor - The owner of a leased distributed energy resource (see, HB589).

Levelized Cost of Energy (LCOE) - A metric that calculates the cost of building and operating a power plant over an assumed lifetime divided by energy production.

Levelized Cost of Storage (LCOS) - A metric that calculates economic break-even price required to charge and discharge electricity in a variable number of cycles per year.

LIHEAP - Low Income Home Energy Assistance Program.

Load - Amount of electricity demand on the grid at any given time.


Measurement and Verification (M&V) - Calculating the amount of energy that has been saved by energy efficiency and clean energy.

Merchant Plant - An electric generating facility that sells electricity at wholesale and is not a qualifying facility.

Micro Grid and Smart Grid - Micro Grid technologies include products that allow an area to operate autonomously, without being connected to the grid. The independence of a micro grid can be permanent, or achieved temporarily through a switch. Smart Grid technologies include products related to updating current electricity grid infrastructure to increase multidirectional communication, data collection, and automation. Find out more.

Municipal Electric Supplier (Muni) - City-owned electric utilities. There are currently 51 municipal electric suppliers in North Carolina.


National Energy Act of 1978 - The federal act adopted in response to the energy crises of the 1970s which includes the Public Utility Regulatory Policies Act (PURPA).

Net Energy Metering (NEM) - A billing system that credits residential and commercial customers at the full retail rate for any excess electricity that they generate and sell back to the utility from the grid. For example, if a residential customer has a PV rooftop system, it may generate more electricity than is needed during the day. If the home is net metered the electricity meter will provide credit against the electricity consumed in the evening. Customers are only billed for the net energy that they use (watch our video explanation).

North Carolina Eastern Municipal Power Agency (NCEMPA) - An organization of 32 municipal power suppliers located in the eastern part of North Carolina.

North Carolina General Assembly (NCGA) - The Senate and the House of Representatives for North Carolina.

North Carolina General Statutes (NCGS) - A statute that operates equally or alike upon all persons, entities, or subjects within North Carolina.

North Carolina Municipal Power Agency Number One (NCMPA1) - An organization of 19 municipal power suppliers located in the middle and western part of North Carolina.

North Carolina Renewable Energy Tracking System (NC-RETS) - A web-based platform to create, track, and manage renewable energy certificate (REC) origination for renewable energy production facilities, utility energy efficiency, demand-side management programs, and hydropower. Read More.

North Carolina Rural Electrification Authority - The North Carolina agency with jurisdiction over certain aspects of electric membership corporations.

North Carolina Utilities Commission (NCUC) - The North Carolina agency with jurisdiction over public utilities and electric generating facilities.


Operation and Maintenance Expenses (O&M) - Cost of running and upkeep for a component of a system.

On-Bill Financing (OBF) - Financing that allows the utility to recoup the cost of a customer's clean energy upgrade by adding it back to the customer's utility bill.

On-bill Program - A customer program where the method of financing energy efficiency or other clean energy improvements uses the utility bill as the repayment vehicle. In on-bill programs, the upfront cost of energy equipment is funded by an electric utility or a third-party financier. There are three types of on-bill programs: on-bill financing, on-bill repayment, and tariffed on-bill financing (Source: ACEEE, SEEA).

On-bill Tariff (OBT) (or Tariffed On-bill Financing (TOB)) - A type of on-bill program where energy upgrades are financed not through a loan, but through a utility offer that pays for upgrades through a cost recovery charge on the customer bill that is less than the estimated savings. The on-bill charge is associated with the meter at the address of the property or facility where upgrades are installed (Source: ACEEE).


Pay As You Save® (PAYS®) - A proven model of tariffed on-bill (TOB) financing developed by the Energy Efficiency Institute that opens up the benefits of cost-effective energy upgrades to all customer types. There is no risk to the customer as the cost recovery charge on the utility bill is substantially less than the estimated savings, so the customer enjoys immediate positive cash flow. See the Energy Efficiency Institute website for more details on PAYS program requirements (Source: LibertyHomes).

PAYS® - See Pay As You Save®

Peak Demand - The time of day when the most energy is being used from the electrical grid.

Peak Load - The historical maximum level of demand on an electrical system.

Powering Energy Efficiency and Impacts Project Framework (PEEIF) - An initiative to enhance the efficiency of energy service delivery to low-income households in northeastern North Carolina. See, PEEIF.

PJM Interconnection - A regional transmission organization serving all or parts of 13 states and Washington D.C. Membership includes Dominion Energy North Carolina.

Power Purchase Agreement (PPA) - A contract between an electric generating facility and an electric purchaser, often a utility.

Proceeding - See, Docket.

Progress Energy - Predecessor of Duke Energy Progress.

Property Assessed Clean Energy (PACE) - A mechanism for financing energy efficiency and renewable energy improvements on private property.

Public Service Commission of South Carolina - The South Carolina agency with jurisdiction over utilities.

Public Staff - North Carolina Utilities Commission - The North Carolina agency directed to represent the “using and consuming public” before the North Carolina Utilities Commission while ensuring the rates that utility companies charge are "reasonable."

Public Utilities Act - The North Carolina act governing utilities, codified as North Carolina General Statutes Chapter 62.

Public Utility - A business producing, generating, transmitting, delivering, or furnishing electricity to the public for compensation. Public utilities are generally subject to the jurisdiction of the North Carolina Utilities Commission. The term does not include persons generating electricity for their own use and generally does not include electric membership corporations and municipal electric suppliers.

Public Utility Regulatory Policies Act of 1978 (PURPA) - One provision of the National Energy Policy Act. The purpose of PURPA was to encourage conservation, reliability, and efficiency in the delivery and generation of electricity, and to do so with equitable retail rates for electric consumers.


Qualifying Facility (QF) - As defined by PURPA, a qualifying facility has the right to sell energy and capacity to the utility, to purchase certain services from the utility, and to interconnect with the utility. A qualifying facility is also relieved of certain regulatory burdens.


Rate of Return - The blended return allowed by combining a utility’s capital structure with the cost of debt and the authorized return on equity. Legal precedent requires that the rate of return be sufficient to allow the utility to attract capital under prudent management.

Rate Schedule - See, Tariff.

Rate Design - Refers to the framework utilities regulators use to set prices for electricity; it impacts consumption and investment decisions across all resources such as energy efficiency, demand response, and traditional and distributed generation.

Regional Transmission Organization (RTO) - An organization responsible for moving electricity through multi-state areas. Regional transmission organizations were formed pursuant to an order from the Federal Energy Regulatory Commission (FERC) in 1999. The only regional transmission organization operating in North Carolina is PJM Interconnection.

Report of Proposed Construction (ROPC) - The report filed with the North Carolina Utilities Commission by an electric generating facility under two megawatts fueled by renewable energy resources that are not owned by utilities prior to construction.

REPS Rider - An annual rider to the rates of a public utility to recover costs associated with their compliance with the Renewable Energy and Energy Efficiency Portfolio Standard. The REPS Rider is capped at set amounts for different customer classes. See, N.C.G.S. § 62-133.8(h).

Reserve/Reserve Margin - The electric generating capacity in excess of peak load constructed to ensure service when demand exceeds historical levels of maximum demand.

Resiliency - As it refers to clean energy, the ability to absorb stresses from extreme weather and sea level rise.

Retail Electricity Rate - The per kilowatt-hour rate that a customer is charged for the electricity they use.

Retrofit - Modifications to existing residential, commercial, or industrial buildings that may improve energy efficiency or decrease energy demand.

Return on Equity - The return that must be offered to investors in order to attract equity. Unlike the cost of debt, there are multiple methods for calculating return on equity, and thus it is frequently litigated in rate cases.

Rider - An additional charge, separate from the base rate, paid by customers to a utility for a specific purpose (see, Fuel Rider and REPS Rider).


Securitization - When a bond is issued to recover the costs of an uneconomic asset. Ratepayers repay the bond at a low-interest rate, instead of paying for the uneconomic asset at the utility’s higher rate of return, which leads to savings for ratepayers.

Senate Bill 3 (SB3) - The legislation passed adopting North Carolina’s Renewable Energy and Energy Efficiency Portfolio Standard. See, N.C. Session Law 2007-397. Find out more here.

Service Area - An area assigned by the North Carolina Utilities Commission (NCUC) to a public utility in which the public utility has the exclusive right to serve all premises.

Smart Grid - Incorporates a network of technologies and services to improve current electricity grid infrastructure with increased multidirectional communication, data collection, and automation. Read more.

Solar - This includes technologies and products that harness sunlight to produce either heat or electricity. Find out more.

Standard Contract PPA - A uniform power purchase agreement approved by a state regulatory authority under which a qualifying facility may opt to sell its electricity to a utility at avoided cost pursuant to PURPA instead of entering into a negotiated contract.


Tariff - A service and billing option offered by a utility. Utilities may offer different rate schedules to different customer classes and for different electric uses.

Tariffed On-bill Financing (or On-bill Tariff (OBT)) - A type of on-bill program where energy upgrades are financed not through a loan, but through a utility offer that pays for upgrades through a cost recovery charge on the customer bill that is less than the estimated savings. The on-bill charge is associated with the meter at the address of the property or facility where upgrades are installed (Source: ACEEE).

Tennessee Valley Authority (TVA) - A federally-owned electric utility operating in the western part of North Carolina.

Third Party Leasing (3PS) - The leasing of distributed energy resources from a lessor to a lessee.

Third Party Sales - Electricity sales from an independent power producer directly to a consumer.

Time Varying Rates (TVR) - Electricity rates that vary over time based on factors such as demand.

Time-of-Use Rates (TOU) - Traditionally, utility prices involve a set rate per kilowatt-hour. A sliding rate scale, however, is structured according to peak and off-peak times of day. This is called a “time-of-use” rate. Under such a plan, electric bills will be determined by how much energy is used and when it is used.

Transmission - Generated electric power is delivered to customers over transmission and distribution lines. Transmission lines carry electricity over long distances from a generating plant to an electrical substation.


Used and Useful Assets - A fundamental principle of utility regulation that requires energy assets be used and useful to ratepayers before they are asked to pay the costs associated with them.


Vertically Integrated Monopoly - Refers to the way utilities are structured in North Carolina and the Southeast. They are monopoly providers of electricity services – generation, transmission, and distribution – within a geographic area. A truly competitive market is one in which electricity generation and management are unbundled.

Volt/VAR Optimization (VVO) - Optimally manages system-wide voltage levels and reactive power flow to achieve efficient distribution grid operation.


Weatherization Assistance Program (WAP) - reduces energy costs for low-income households by increasing the energy efficiency of their homes, while ensuring their health and safety.

Weatherization - The process of making a building more resistant to the effects of changing weather and increasing its energy efficiency.

Wholesale Energy Competition - Giving an energy distributor the option to buy power from a variety of power producers while the producers compete to sell their power to different distribution utilities.

Wind - This includes technologies and products related to the harnessing of wind energy to produce electricity or mechanical force.

Is there a term that should be in our glossary but isn't?