Roadmap for Incorporating Energy 

Efficiency/Renewable Energy

Policies and Programs into State and Tribal 

Implementation Plans

Appendix A: Glossary
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EPA-456/D-12-001b

July 2012

Roadmap for Incorporating Energy Efficiency/Renewable Energy

Policies and Programs into State and Tribal Implementation Plans

Appendix A: Glossary

By:

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Outreach and Information Division

Research Triangle Park, North Carolina

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Outreach and Information Division

Research Triangle Park, North Carolina
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ACKNOWLEDGMENTS

We would like to acknowledge substantial contributions from members of an inter-office EPA 

team that included the Office of Atmospheric Programs, the Office of Policy Analysis and 

Review, the Office of General Counsel and Regions 1 and 6. This document also reflects 

comments received from a number of stakeholders, including state and local air quality 

agencies.
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Allowance: An allowance is an 

authorization to emit a specific amount of a 

pollutant under a cap and trade program. 

For example, under the U.S. Sulfur Dioxide 

(SO2) Allowance Trading Program, one 

allowance is the authorization to emit 1 ton 

of SO2. Allowances are used for compliance 

and can be traded among sources 

participating in the cap and trade program.

Annual Energy Outlook: Prepared by the 

U.S. Department of Energy’s Energy 

Information Administration (EIA), the 

Annual Energy Outlook presents long-term 

projections of energy supply, demand, and 

prices through 2035, based on results from 

EIA’s National Energy Modeling System.

Baseline Projections: Baseline projections, 

including energy supply and demand and 

related emissions, are intended to describe 

future year conditions and typically assume 

continuation of current trends and no 

changes in laws and regulations. Baseline 

projections are sometimes referred to as 

“business-as-usual” projections. A baseline 

projection can be used for comparison with 

one or more alternative policy scenarios to 

assess the impacts of various policies.

Combined Heat and Power: Also known as 

cogeneration, combined heat and power 

(CHP) is an efficient, clean, and reliable 

approach to generating power and thermal 

energy from a single fuel source. Since less 

fuel is burned to produce each unit of 

energy output, CHP reduces air pollution 

and greenhouse gas emissions. As a result, 

the emission benefits from CHP systems can 

be recognized for State Implementation 

Plan/Tribal Implementation Plan credit.

Typical CHP configurations include gas 

turbines or engines with heat recovery units 

or steam boilers with a steam turbine. 

Clean Air Act: The Clean Air Act (CAA) is the 

law that defines the U.S. Environmental 

Protection Agency’s responsibilities for 

protecting and improving the nation's air 

quality and the stratospheric ozone layer. 

The last major change in the law occurred 

when Congress enacted the CAA 

Amendments of 1990. Legislation passed 

since then has made several minor changes.

Criteria Air Pollutant: The Clean Air Act

requires the U.S. Environmental Protection 

Agency to set National Ambient Air Quality 

Standards for six common air pollutants. 

These common air pollutants (also known 

as "criteria pollutants") are found all over 

the country. They are particle pollution 

(often referred to as particulate matter), 

ground-level ozone, carbon monoxide, 

sulfur oxides, nitrogen oxides, and lead. 

Demand: The time rate of energy flow. 

Demand usually refers to electric power 

measured in kilowatt but can also refer to 

natural gas, usually as British thermal 

unit/hour (Btu/hr), kiloBtu/hr, or 

therms/day. 

Discount Rate: A measure of the time value 

of money. 

Electric Generating Unit: This is an entity 

that supplies electricity to the electricity 

system relying on a variety of fuels.

Electricity Dispatch Models: Electricity 

dispatch models (also commonly referred to 

as “production cost” models) simulate the 

dynamic operation of the electric system, 

generally on a least-cost system dispatch. 

In general, these models optimize the 

dispatch of the system based on the 

variable costs of each resource and any 

operational constraints that have been 

entered into the model. These models are 
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helpful in assessing which existing plants 

are displaced. These models are also used 

in short-term planning and regulatory 

support.

Emissions & Generation Resource 

Integrated Database: The Emissions & 

Generation Resource Integrated Database is 

a comprehensive inventory of 

environmental attributes of electric power 

plants, providing air emissions data for the 

electric power sector. The U.S. 

Environmental Protection Agency maintains 

the database.1

Energy Efficiency: Energy efficiency is

achieving the same or better level of service 

or performance with lower energy

consumption. Examples include highefficiency appliances; efficient lighting;

high-efficiency heating, ventilating and air 

conditioning systems or control 

modifications; efficient building design;

advanced electric motor drives; combined 

heat and power; and heat recovery 

systems.

Energy Efficiency Policy: Energy efficiency 

(EE) policy means an enacted law and/or 

regulation by a state, locality, or public 

utility commission order which requires 

applicable entities to adopt energy efficient 

technologies and/or practices, or to 

undertake activities to further such 

adoption in the marketplace. It can include: 

(1) policies that establish minimum 

efficiency requirements for new homes and 

buildings (building energy codes) or 

appliances (appliance standards); (2) 

policies that establish requirements on 

utilities (or other program administrators) 

to deliver a specified amount of energy 

 

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For more information, go to: www.epa.gov/egrid.

savings by developing EE programs to 

increase market adoption of EE 

technologies and practices (EE resource 

standards); and (3) policies that commit to 

specified funding levels dedicated to 

implementing EE programs (e.g., EE rebates 

or combined heat and power capital cost 

incentives from public benefits funds). 

State and local governments both have 

authority over EE policies. EE policies are 

generally enforced over a multi-year period 

or until changed or updated by revised 

legislation or regulation (e.g., adopting a 

revised building energy code). These 

programs can be funded through ratepayer 

surcharges, federal funds, proceeds from 

pollution auctions such as the Regional 

Greenhouse Gas Initiative, or any 

combination of the above. 

Electric-sector EE and renewable energy 

policies, programs and projects that will 

result in quantifiable reductions in 

emissions at existing fossil fuel-fired electric 

generating units and that improve air 

quality in a nonattainment area can be 

accounted for in State and Tribal 

Implementation Plans. 

Energy Efficiency Program: Energy 

efficiency (EE) program means a program 

designed to increase adoption of energy 

efficient technologies and practices in 

particular end-use sectors (or specific 

market segments within a sector) through 

education and outreach, financial 

incentives, and/or technical assistance. An 

individual EE program can be run by a 

utility, state or local government, and/or 

third parties. In most cases, EE program 

administrators (i.e., utilities, state agencies, 

or 3rd parties) develop and implement EE 

programs to meet adopted EE policy 

objectives. State Public Utilities 
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Commissions oversee and approve the EE 

programs funded with rate-payer resources. 

EE programs typically operate over a one to 

three year period. 

Electric-sector EE and renewable energy 

policies, programs and projects that will 

result in quantifiable reductions in 

emissions at existing fossil fuel-fired electric 

generating units and that improve air 

quality in a nonattainment area can be 

accounted for in State and Tribal 

Implementation Plans.

Energy Efficiency Project or Measure: 

Installation of equipment, installation of 

subsystems or systems, or modification of 

equipment, subsystems, systems, or 

operations on the customer side of the 

meter, in order to improve energy 

efficiency (EE). These projects or measures 

can be taken in conjunction with or 

independent of an EE policy or program. 

Energy Efficiency Resource Standard: An 

Energy Efficiency Resource Standard (also 

known as Energy Efficiency Portfolio 

Standards) consists of electric and gas 

savings targets for utilities, often with 

flexibility to achieve them through a 

market-based trading system or a buyoutoption to purchase credits at a default 

price.

Energy Model: This refers to simulation 

models that utilize computer modeling 

software to analyze the electric power 

system Energy models are capable of 

simulating electric system dispatch, 

forecasting future capacity and technology 

changes, and/or representing behavior of 

system-wide energy markets. Examples of 

energy models include: Energy 2020, 

Integrated Planning Model, MARKAL, 

National Energy Modeling System, 

Strategist by Ventyx.

Evaluation, Measurement and Verification: 

The performance of studies and activities 

aimed at determining the effects of a 

program; any of a wide range of assessment 

activities associated with understanding or 

documenting program performance, 

assessing program or program-related 

markets and market operations; any of a 

wide range of evaluative efforts including 

assessing policy or program-induced 

changes in energy efficiency markets, levels 

of demand or energy savings, and program 

cost-effectiveness.

Federal Enforceability: This refers to what 

occurs in the State Implementation Plan 

(SIP) planning process when the U.S. 

Environmental Protection Agency (EPA)

approves a SIP control strategy submitted 

to it for review and the SIP becomes 

federally enforceable. A federally

enforceable SIP provides EPA with authority 

to ensure the SIP is implemented. Once 

energy efficiency/renewable energy policies 

and programs become federally 

enforceable, EPA has the authority under 

the Clean Air Act (CAA) to apply CAAmandated penalties against the 

noncompliant party. 

Future Attainment Year Baseline: A 

specific year in the future for which a state, 

tribal or local agency must show attainment 

of the National Ambient Air Quality 

Standard. The baseline forecast of 

emissions in a future attainment year refers 

to the emissions that will result if no future 

policies or programs are adopted and 

implemented. A baseline forecast of future 

emissions is made when an area prepares a 

State or Tribal Implementation Plan 

(SIP/TIP). Future year emission projections 
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provide a basis for considering control 

strategies for (SIPs/TIPs), conducting 

attainment analyses, and tracking progress 

towards meeting air quality standards. 

Heating, Ventilating, and Air Conditioning: 

Heating, ventilating, and air conditioning 

refers to technology to provide for indoor 

environmental comfort.

Independent System Operator: 

Independent system operators (ISOs) serve 

as grid operators, coordinating the power 

grid to ensure reliable delivery. ISOs also 

match generation to load instantaneously 

to keep electricity supply and demand 

balanced and administer forward capacity 

markets where utilities can use energy 

efficiency as a resource to meet demand.

Integrated Planning Model: The EPA uses 

the Integrated Planning Model (IPM) to 

analyze the impact of environmental 

policies on the electric power sector in the 

48 contiguous states and the District of 

Columbia. This model simultaneously 

models electric power, fuel, and 

environmental markets associated with

electric production. It is a capacity 

expansion and system dispatch model. 

Dispatch is based on seasonal, segmented 

load duration curves, as defined by the 

user. IPM can be used to model the 

impacts of clean energy resources on the 

electric sector in the short and long term.

Kilowatt-Hour: A kilowatt-hour (KWh) is a 

unit of work or energy, equivalent to 1 

kilowatt (1,000 watts) of power expended 

for 1 hour. One kWh is equivalent to 3,412 

British thermal units.

Load Shapes: Representations such as 

graphs, tables, and databases that describe 

energy consumption rates as a function of 

another variable such as time or outdoor air 

temperature. 

Marginal Emission Rates: The emissions 

associated with the marginal generating 

unit in each hour of the day. 

Measurement and verification: Data 

collection, monitoring, and analysis 

associated with the calculation of gross 

energy and demand savings from individual 

sites or projects. Measurement and 

verification can be a subset of program 

impact evaluation. 

Megawatt: A megawatt is one million 

watts of electricity.

Megawatt-hour: A megawatt-hour is one

thousand kilowatt-hours or 1 million watthours.

National Ambient Air Quality Standards: 

The Clean Air Act (CAA), which was last 

amended in 1990, requires the U.S. 

Environmental Protection Agency to set 

National Ambient Air Quality Standards

(NAAQS) for pollutants considered harmful 

to public health and the environment. The 

CAA established two types of NAAQS. 

Primary standards set limits to protect 

public health, including the health of 

"sensitive" populations such as asthmatics, 

children, and the elderly. Secondary 

standards set limits to protect public 

welfare, including protection against 

decreased visibility, damage to animals, 

crops, vegetation, and buildings.

Nitrogen Oxides: Nitrogen oxides can refer 

to a binary compound of oxygen and 

nitrogen, or a mixture of such compounds.

North American Electric Reliability 

Corporation: The North American Electric 

Reliability Corporation (NERC) is the electric 
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reliability organization certified by the 

Federal Energy Regulatory Commission to 

establish and enforce reliability standards 

for the bulk-power system. NERC ensures

the reliability of the North American bulk 

power system. 

“On the books” Energy Efficiency/ 

Renewable Energy Policies: Energy 

efficiency/renewable energy policies that 

have been adopted by a legislative or 

regulatory body.

“On the way” Energy Efficiency/ 

Renewable Energy Policies: Energy 

efficiency/renewable energy policies that 

are planned for adoption by a legislative or 

regulatory body prior to the submittal of 

the State or Tribal Implementation Plans in 

question to the U.S. Environmental 

Protection Agency.

Peak Demand: The maximum level of 

metered demand during a specified period, 

such as a billing month or a peak demand 

period. 

Portfolio: A portfolio is either (1) a 

collection of similar programs addressing 

the same market, technology, or 

mechanisms or (2) the set of all programs 

conducted by one organization.

Power Pool: A power pool is an association 

of two or more interconnected electric 

systems that agree to coordinate 

operations and planning for improved 

reliability and efficiencies.

Program: A group of projects, with similar 

characteristics and installed in similar 

applications.

Public Utilities Commission or Public 

Service Commission: A public utilities 

commission or public service commission is 

a governing body that regulates the rates 

and services of a public utility. In some 

cases, government bodies with the title 

"Public Service Commission" may be civil 

service oversight bodies, rather than utility

regulators.

Renewable Energy: Renewable energy 

resources are naturally replenishing but 

flow-limited. They are virtually 

inexhaustible in duration but limited in the 

amount of energy that is available per unit 

of time. Renewable energy resources 

include biomass, hydro, geothermal, solar, 

wind, ocean thermal, wave action, and tidal 

action.

Renewable Energy Policy: Regulations, 

statutes, or state public utility commission 

orders that require parties to acquire 

renewable energy or to commit to funding 

levels for programs aimed at acquiring 

renewable energy. 

Electric-sector energy efficiency and 

renewable energy policies, programs and 

projects that will result in quantifiable 

reductions in emissions at existing fossil 

fuel-fired electric generating units and that 

improve air quality in a nonattainment area 

can be accounted for in State or Tribal 

Implementation Plans. 

Renewable Energy Program: Renewable 

energy program means a program designed 

to increase the production and use of 

renewable energy sources through resource 

development and procurement, education 

and outreach, financial incentives, and/or 

technical assistance. 

Electric-sector energy efficiency and 

renewable energy policies, programs and 

projects that will result in quantifiable 

reductions in emissions at existing fossil 
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fuel-fired electric generating units and that 

improve air quality in a nonattainment area 

can be accounted for in State or Tribal 

Implementation Plans.

Renewable Portfolio Standard: A

renewable portfolio standards are a 

requirement on retail electric suppliers to 

supply a minimum percentage or amount of 

their retail load with eligible sources of 

renewable energy (e.g., solar, wind, 

biomass and geothermal).

Retail Electricity Supplier: A person or 

entity that sells electrical energy to end-use 

customers, including but not limited to 

electric utility distribution companies 

supplying basic service or any successor 

service to end-use customers.

State Implementation Plans: A State 

Implementation Plan (SIP) is a plan 

developed by a state detailing how that 

state will comply with the requirements of 

the federal Clean Air Act, administered by 

the U.S. Environmental Protection Agency. 

The SIP consists of narrative, rules, technical 

documentation, and agreements that an 

individual state will use to meet the 

National Ambient Air Quality Standards. 

State Implementation Plan/Tribal 

Implementation Plan Credit: Credit for 

State and Tribal Implementation Plans 

means emission reductions, achieved by 

using technologies or strategies, used by a

state or tribe for the purpose of meeting 

emission reduction requirements in its 

reasonable further progress, attainment or 

maintenance (control) strategy.

Tribal Implementation Plans: Although not 

required to do so, a tribe with “treatment 

as state” eligibility may develop its own air 

quality control plan, called a Tribal 

Implementation Plan, for approval by the 

U.S. Environmental Protection Agency

(EPA). A TIP enacted by a tribal government 

and approved by the EPA is legally binding 

under both tribal and federal law and may 

be enforced by the tribe, EPA and the 

public.

Voluntary Energy Efficiency/Renewable 

Energy Programs: These are energy 

efficiency/renewable energy programs are 

not directly enforceable against a source or 

party administering the program. Examples 

could include municipal government energy 

conservation plans or public awareness 

campaigns.

Emerging/Voluntary Measures Policy: In 

September 2004, the U.S. Environmental 

Protection Agency issued guidance entitled: 

“Incorporating Emerging and Voluntary 

Measures in a State Implementation Plan 

(SIP).” The guidance provides a policy for 

areas to try new types of pollutant 

reduction strategies such as energy 

efficiency/renewable energy programs to 

attain or maintain the National Ambient Air 

Quality Standards and meet Clean Air Act

requirements. 

Watt: The watt is a standard unit of 

electrical power equivalent to one ampere 

flowing across a potential difference of one 

volt. A watt is equal to 1/746 horse power.

Weight-of-Evidence: The augmentation of 

a State Implementation Plan/Tribal 

Implementation Plan modeled attainment 

test with supplemental analyses, which may 

yield a conclusion different from that 

indicated by the modeled attainment test 

results alone.
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United States

Environmental Protection

Agency

Office of Air Quality Planning and Standards

Outreach and Information Division

Research Triangle Park, NC

Publication No. EPA-456/D-12-001b

July 2012