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Energy Services Companies (ESCOs) & Demand-Side Providers Industry Acronyms

Energy Services Companies (ESCOs) & Demand-Side Providers Industry Acronyms

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Designed for leaders and practitioners across Energy & Utilities, this glossary explains operational, technical, contractual, regulatory, and performance terminology used in the Energy Services Companies (ESCOs) & Demand-Side Providers Practice. It supports clearer evaluation of efficiency projects, demand-response programs, financing structures, controls, and verified savings.

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

A
ACEEE American Council for an Energy-Efficient Economy:
A nonprofit organization that researches energy-efficiency technologies, policies, markets, and utility programs and publishes widely used scorecards and analyses.
ADR Automated Demand Response:
The use of signals and controls to reduce or shift customer loads automatically in response to grid, price, or program conditions.
AEE Association of Energy Engineers:
A professional association that provides training and credentials for energy managers, auditors, measurement professionals, and related specialists.
AFDD Automated Fault Detection and Diagnostics:
Analytics that identify abnormal equipment behavior, diagnose likely causes, and prioritize corrective actions to sustain energy and operational performance.
AFUE Annual Fuel Utilization Efficiency:
A seasonal measure of how effectively a furnace or boiler converts fuel into useful heat, commonly used when evaluating heating upgrades.
AHRI Air-Conditioning, Heating, and Refrigeration Institute:
An industry organization whose equipment certification programs and rating standards support consistent comparisons of heating, cooling, and refrigeration performance.
AHU Air Handling Unit:
Equipment that conditions and circulates air through a building; its fans, coils, dampers, filters, and controls are frequent retrofit targets.
AMI Advanced Metering Infrastructure:
Interval meters, communications, and supporting systems that provide granular consumption data for baselining, demand management, and savings analysis.
ANSI/ASHRAE/IES 90.1 American National Standards Institute/American Society of Heating, Refrigerating and Air-Conditioning Engineers/Illuminating Engineering Society Standard 90.1:
The energy standard for sites and buildings except low-rise residential buildings, widely used as a code baseline and reference point for retrofit performance.
ARC Aggregator of Retail Customers:
An entity that combines multiple customers’ demand reductions for participation in organized wholesale electricity markets under applicable market rules.
ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers:
A technical society whose standards and guidance address energy audits, building performance, ventilation, commissioning, controls, and heating and cooling systems.
B
BAS Building Automation System:
A network of sensors, controllers, software, and actuators used to schedule and regulate building equipment and implement energy-saving sequences.
BEM Building Energy Modeling:
Computer simulation of building energy use under defined weather, occupancy, equipment, and operating assumptions to estimate savings and compare design alternatives.
BEMS Building Energy Management System:
A controls and analytics platform focused on monitoring, managing, and optimizing a building’s energy consumption and demand.
BMS Building Management System:
An integrated platform for supervising building services such as heating, cooling, ventilation, lighting, security, and other operational systems.
BPI Building Performance Institute:
A standards and credentialing organization supporting residential energy assessments, weatherization, healthy-home work, and quality assurance.
BTM Behind-the-Meter:
Customer-sited equipment or activity located on the premises side of the utility meter, including efficiency controls and flexible loads.
Btu British Thermal Unit:
A unit of thermal energy commonly used to quantify fuel consumption, heating and cooling loads, and project savings.
BYOD Bring Your Own Device:
A program model that enrolls customer-purchased connected devices, such as smart thermostats, for energy-efficiency or demand-response services.
C
CBCP Certified Building Commissioning Professional:
A credential for professionals who plan, manage, and verify commissioning activities and building-system performance.
CBECS Commercial Buildings Energy Consumption Survey:
A U.S. survey providing benchmark data on commercial building characteristics, energy use, fuels, and expenditures.
CBL Customer Baseline Load:
An estimate of the electricity a customer would have consumed absent a demand-response event, used to calculate delivered load reduction.
CDD Cooling Degree Days:
A weather indicator used to normalize cooling-related energy consumption and explain seasonal variation in baseline models.
CEA Certified Energy Auditor:
A professional credential demonstrating competence in facility energy assessments, data analysis, equipment evaluation, and audit reporting.
CEM Certified Energy Manager:
A professional credential covering energy management, efficiency economics, building systems, procurement, and performance improvement.
CHP Combined Heat and Power:
The simultaneous production of electricity and useful thermal energy from one fuel source, often evaluated as an efficiency and resilience measure.
C&I Commercial and Industrial:
A customer segment encompassing businesses, institutions, manufacturing plants, and other nonresidential facilities with distinct efficiency and load-management needs.
CIBSE Chartered Institution of Building Services Engineers:
A professional institution whose guidance and benchmarks are widely used for building energy, lighting, controls, ventilation, and engineering design.
CMVP Certified Measurement and Verification Professional:
A credential for professionals responsible for developing savings plans, selecting methods, analyzing data, and documenting verified performance.
COP Coefficient of Performance:
The ratio of useful heating or cooling output to energy input, used to compare heat pumps, chillers, and refrigeration equipment.
CP Coincident Peak:
A customer’s demand at the time the relevant utility or power system reaches its peak, often affecting capacity costs and demand-management value.
C-PACE Commercial Property Assessed Clean Energy:
A financing mechanism that repays eligible commercial-building energy improvements through a property assessment tied to the building.
CPP Critical Peak Pricing:
A retail rate design that applies substantially higher prices during limited high-stress periods to encourage customers to reduce or shift demand.
CSE Cost of Saved Energy:
A metric that divides the cost of an efficiency investment or program by its lifetime energy savings, enabling comparison with supply alternatives.
CSP Curtailment Service Provider:
An intermediary that recruits customers, manages demand-response participation, submits market offers, and coordinates performance and settlement.
CT Current Transformer:
A metering device that scales electrical current to a measurable level for submeters, power monitors, and control systems.
CUSUM Cumulative Sum:
A method that accumulates differences between actual and expected energy use, making persistent savings trends or performance drift easier to detect.
CV(RMSE) Coefficient of Variation of the Root-Mean-Square Error:
A normalized measure of model error used to assess whether an energy baseline fits observed consumption with acceptable precision.
Cx Commissioning:
A quality-focused process that verifies building systems are designed, installed, tested, operated, and documented to meet defined requirements.
CxA Commissioning Authority:
The professional or firm responsible for leading commissioning, documenting findings, and verifying resolution of system-performance issues.
D
DCV Demand-Controlled Ventilation:
A control strategy that adjusts outdoor airflow according to measured occupancy or air-quality indicators, reducing unnecessary conditioning energy.
DDC Direct Digital Control:
Microprocessor-based control of building equipment using programmable sequences, sensors, and networked controllers.
DEC Display Energy Certificate:
A United Kingdom certificate showing the measured operational energy performance of qualifying public buildings and recommendations for improvement.
DEER Database for Energy Efficient Resources:
A California resource containing standardized savings estimates, costs, and useful-life assumptions for energy-efficiency measures and program planning.
DHW Domestic Hot Water:
Heated water used for washing, sanitation, kitchens, and similar building needs; its production and distribution are common efficiency targets.
DLC DesignLights Consortium:
An organization that maintains qualified-product lists and technical requirements used by many commercial lighting efficiency programs.
DLC Direct Load Control:
A demand-response approach that allows an authorized operator to cycle, curtail, or adjust enrolled customer equipment during defined events.
DOAS Dedicated Outdoor Air System:
A ventilation system that conditions outdoor air separately from space heating and cooling, enabling better humidity control and efficient equipment operation.
DOE U.S. Department of Energy:
The federal department responsible for major efficiency standards, research, technical resources, weatherization, and federal energy-management programs.
DR Demand Response:
Changes in electricity consumption made in response to prices, incentives, reliability events, or grid needs.
DRA Demand Response Aggregator:
An entity that combines and manages flexible customer loads to satisfy program or market participation requirements.
DRMS Demand Response Management System:
A software platform used to enroll customers, dispatch events, communicate with devices, track performance, and support settlements.
DRP Demand Response Provider:
A registered or contracted entity that offers customer load flexibility into a utility program or organized electricity market.
DSM Demand-Side Management:
Programs and actions that influence customer energy use, including efficiency, conservation, load shifting, and peak-demand reduction.
E
EaaS Energy as a Service:
A commercial model in which a provider finances, installs, operates, or optimizes energy assets in exchange for recurring or performance-based payments.
EBCx Existing Building Commissioning:
A systematic process for improving how an occupied building’s systems operate, often through low-cost control, maintenance, and sequence corrections.
ECM Energy Conservation Measure:
A specific equipment, control, operational, or building-envelope improvement intended to reduce energy consumption or demand.
ECM Electronically Commutated Motor:
A high-efficiency brushless motor with electronic controls, often applied to fans and pumps requiring efficient variable-speed operation.
ECO Energy Conservation Opportunity:
A potential operational or capital improvement identified through an audit for further engineering, savings, cost, and feasibility analysis.
EE Energy Efficiency:
The delivery of the same or improved service using less energy, typically through technology upgrades, controls, maintenance, or process changes.
EED Energy Efficiency Directive:
European Union legislation establishing energy-saving obligations, audit requirements, public-sector provisions, and efficiency policy frameworks.
EEM Energy Efficiency Measure:
An equipment, controls, envelope, or operating change designed to lower energy use while maintaining required service levels.
EER Energy Efficiency Ratio:
A measure of cooling output relative to electrical input at specified test conditions, used to compare air-conditioning equipment.
EERS Energy Efficiency Resource Standard:
A policy requiring utilities or program administrators to achieve defined energy-savings targets over time.
EISA Energy Independence and Security Act:
A U.S. federal statute containing provisions for equipment efficiency, federal facility performance, lighting, buildings, and energy management.
EMCS Energy Management and Control System:
Hardware and software used to monitor energy, control building equipment, implement schedules, and manage operating strategies.
EM&V Evaluation, Measurement, and Verification:
The broader assessment of program savings, impacts, attribution, implementation, and cost-effectiveness using engineering, metering, and statistical methods.
EnB Energy Baseline:
A quantitative reference representing energy performance over a defined period, against which subsequent improvement is evaluated.
EnMS Energy Management System:
An organizational framework of policies, processes, responsibilities, data, and continual-improvement practices for managing energy performance.
EnPI Energy Performance Indicator:
A quantitative metric selected to track and evaluate energy performance at the organization, facility, process, system, or equipment level.
EPA U.S. Environmental Protection Agency:
The federal agency responsible for environmental regulation and major building benchmarking and energy-performance resources.
EPAct Energy Policy Act:
A name used for major U.S. federal energy statutes containing provisions relevant to performance contracting, equipment standards, tax incentives, and federal facilities.
ePB eProject Builder:
A U.S. Department of Energy system for entering, tracking, and reporting performance-contracting project data, costs, measures, and savings.
EPBD Energy Performance of Buildings Directive:
European Union legislation governing building energy performance, renovation planning, certificates, technical systems, and related requirements.
EPC Energy Performance Certificate:
A regulated building rating document that reports modeled or measured energy performance and typically recommends potential improvements.
EPC Energy Performance Contract:
A contract linking the delivery and payment of energy improvements to defined savings or performance outcomes.
ERV Energy Recovery Ventilator:
Ventilation equipment that transfers heat and, in many designs, moisture between exhaust and incoming air streams to reduce conditioning loads.
ESA Energy Services Agreement:
A financing and service arrangement under which a provider implements improvements and the customer pays for delivered services or realized savings.
ESCO Energy Service Company:
A provider that develops and implements energy projects and may arrange financing, guarantee savings, and perform ongoing verification and maintenance.
ESOS Energy Savings Opportunity Scheme:
The United Kingdom’s mandatory energy-assessment framework for qualifying large organizations, covering buildings, transport, and industrial processes.
ESPC Energy Savings Performance Contract:
A performance-based agreement in which facility improvements are funded and repaid from contractually defined energy and operating savings.
EUI Energy Use Intensity:
Energy consumption normalized by building floor area, commonly used for benchmarking, target setting, and comparison across facilities.
EVO Efficiency Valuation Organization:
The organization that maintains the International Performance Measurement and Verification Protocol and supports professional training in savings verification.
F
FAR Federal Acquisition Regulation:
The primary set of rules governing U.S. federal procurement, including contracting requirements relevant to federally sponsored energy projects.
FDD Fault Detection and Diagnostics:
The process of identifying equipment or control faults and determining likely causes through rules, models, trends, or analytics.
FEMP Federal Energy Management Program:
A U.S. Department of Energy program providing contracting support, guidance, tools, and technical assistance for federal facility energy management.
FERC Federal Energy Regulatory Commission:
The U.S. regulator whose orders and rules affect wholesale-market participation, compensation, aggregation, and access for demand-side resources.
FIM Facility Improvement Measure:
A defined equipment, controls, infrastructure, or operational upgrade included in a facility performance project.
G
GESPC Guaranteed Energy Savings Performance Contract:
A public-sector contract under which a provider guarantees specified savings sufficient to support project economics, subject to agreed conditions and verification.
GSHP Ground-Source Heat Pump:
A heating and cooling system that exchanges heat with the ground or groundwater, often evaluated for electrification and long-term efficiency projects.
H
HDD Heating Degree Days:
A weather indicator used to normalize heating-related energy consumption and estimate the effect of outdoor temperature on baseline use.
HEMS Home Energy Management System:
A residential platform that monitors and controls connected loads to improve efficiency, manage peak demand, or respond to external signals.
HEPA High-Efficiency Particulate Air:
A high-performance filtration classification relevant to indoor-air-quality upgrades and the fan-energy impacts of filtration strategies.
HPWH Heat Pump Water Heater:
Equipment that transfers ambient heat into stored water, generally using less electricity than conventional electric-resistance water heating.
HPXML Home Performance Extensible Markup Language:
A data standard for exchanging residential building, audit, measure, and energy-performance information across software and programs.
HRV Heat Recovery Ventilator:
Ventilation equipment that transfers sensible heat between exhaust and incoming air streams while maintaining separate airflow paths.
HSPF Heating Seasonal Performance Factor:
A seasonal heating-efficiency rating used for certain heat-pump equipment and retrofit comparisons.
HVAC Heating, Ventilation, and Air Conditioning:
Building systems that maintain thermal comfort and indoor air conditions and commonly represent a major source of retrofit savings.
I
IAQ Indoor Air Quality:
The condition of air inside a building, including pollutants, humidity, ventilation, and filtration factors that must be considered alongside energy savings.
ICC International Code Council:
The organization that develops widely adopted model building codes, including requirements affecting energy retrofits and code compliance.
ICP Investor Confidence Project:
A standardized project-development framework intended to improve consistency in energy-efficiency engineering, documentation, underwriting, and performance assessment.
IDIQ Indefinite-Delivery, Indefinite-Quantity:
A contracting structure used when the exact timing or quantity of future project work is not known, including federal performance-contracting programs.
IECC International Energy Conservation Code:
A model code establishing minimum energy-efficiency requirements for residential and commercial buildings.
IEER Integrated Energy Efficiency Ratio:
A weighted cooling-efficiency metric representing performance at multiple load conditions for certain commercial equipment.
IES Illuminating Engineering Society:
A professional society that develops lighting recommendations, measurement methods, and standards used in lighting retrofit design and evaluation.
IGA Investment-Grade Audit:
A detailed technical and financial assessment used to define project scope, costs, savings, risks, and contractual guarantees with sufficient rigor for financing.
IgCC International Green Construction Code:
A model code addressing high-performance building requirements, including energy, water, materials, and indoor environmental quality.
IPMVP International Performance Measurement and Verification Protocol:
A widely used framework for selecting methods, defining boundaries, adjusting baselines, and documenting energy and water savings.
IRA Inflation Reduction Act:
A U.S. federal law that expanded incentives and funding for building efficiency, electrification, home energy upgrades, and related workforce and rebate programs.
IREE Investor Ready Energy Efficiency:
A certification indicating that a project was developed in accordance with standardized protocols intended to support investor and lender review.
ISO 50001 International Organization for Standardization 50001, Energy Management Systems—Requirements with Guidance for Use:
The principal international standard for establishing, maintaining, and continually improving an organizational energy-management system.
ISO 50002 International Organization for Standardization 50002, Energy Audits—Requirements with Guidance for Use:
An international standard defining principles and requirements for conducting consistent, documented energy audits.
ISO 50006 International Organization for Standardization 50006, Evaluating Energy Performance Using Energy Performance Indicators and Energy Baselines:
Guidance for establishing and using performance indicators and baselines to evaluate organizational energy improvement.
ISO 50015 International Organization for Standardization 50015, Measurement and Verification of Energy Performance of Organizations:
Guidance on the principles, planning, data, analysis, and reporting used to substantiate organizational energy-performance improvement.
K
kBtu Thousand British Thermal Units:
A thermal-energy unit commonly used in building benchmarking, fuel analysis, and area-normalized energy metrics.
kW Kilowatt:
A unit of instantaneous power used to measure equipment load, facility demand, and demand-response performance.
kWh Kilowatt-Hour:
A unit of electrical energy equal to one kilowatt used for one hour, commonly used for billing and savings calculations.
kW/ton Kilowatts per Ton of Refrigeration:
A chiller-system efficiency metric expressing electrical input relative to delivered cooling capacity; lower values generally indicate better performance.
L
LCCA Life-Cycle Cost Analysis:
An economic method that evaluates acquisition, energy, maintenance, replacement, and residual costs over a defined study period.
LED Light-Emitting Diode:
A solid-state lighting technology valued for high efficacy, controllability, long service life, and reduced maintenance requirements.
LEED Leadership in Energy and Environmental Design:
A green-building rating system that recognizes performance across energy, water, materials, site, and indoor-environmental categories.
LF Load Factor:
The ratio of average electrical demand to peak demand over a period, used to understand utilization patterns and demand-cost opportunities.
LLLC Luminaire-Level Lighting Controls:
Sensors and controllers embedded in or associated with individual fixtures to enable occupancy response, daylighting, scheduling, and granular data.
LOTO Lockout/Tagout:
A safety procedure for isolating hazardous energy before equipment inspection, installation, maintenance, or retrofit work.
LPD Lighting Power Density:
Installed lighting wattage divided by floor area, used for code compliance, benchmarking, and retrofit design.
M
MBCx Monitoring-Based Commissioning:
An ongoing approach that combines interval data, system trends, and analytics to identify and correct operating problems.
MEP Mechanical, Electrical, and Plumbing:
The principal building-engineering disciplines involved in auditing, designing, installing, and commissioning facility upgrades.
MEPS Minimum Energy Performance Standards:
Regulatory minimums for the efficiency of appliances, equipment, buildings, or rented properties, depending on the jurisdiction.
MERV Minimum Efficiency Reporting Value:
A rating of an air filter’s particle-removal performance that also informs pressure-drop and fan-energy considerations.
MESA Managed Energy Services Agreement:
A service and financing model in which a provider manages energy supply and improvements while the customer pays under a defined service structure.
MMBtu Million British Thermal Units:
A thermal-energy unit commonly used for natural gas, steam, fuel, and whole-facility savings calculations.
MUSH Municipalities, Universities, Schools, and Hospitals:
A major institutional customer segment for performance contracting because of its large facility portfolios, long planning horizons, and capital needs.
M&V Measurement and Verification:
The process of planning, measuring, calculating, and reporting energy or demand savings relative to an adjusted baseline.
MW Megawatt:
A unit equal to one million watts, used to express aggregated demand, capacity, and large load reductions.
MWh Megawatt-Hour:
A unit equal to one megawatt delivered or consumed for one hour, used for large-scale energy and savings quantities.
N
NABERS National Australian Built Environment Rating System:
A performance-rating system that measures operational energy, water, waste, and indoor-environment outcomes for buildings and tenancies.
NAC Normalized Annual Consumption:
Estimated annual energy use adjusted to standard weather or other representative conditions for comparison and savings analysis.
NAECA National Appliance Energy Conservation Act:
A U.S. federal law establishing efficiency standards for specified residential appliances and equipment.
NAESCO National Association of Energy Service Companies:
A U.S. industry association representing providers and supporting accreditation, policy engagement, and performance-contracting practices.
NASEO National Association of State Energy Officials:
An association representing U.S. state and territory energy offices and supporting public-sector energy programs, policies, and financing initiatives.
NCP Non-Coincident Peak:
The maximum demand recorded for an individual customer or facility regardless of when the broader system peak occurs.
NEB Non-Energy Benefits:
Positive outcomes beyond energy savings, such as improved comfort, productivity, health, maintenance, resilience, or asset value.
NECPA National Energy Conservation Policy Act:
A U.S. federal law establishing energy-management requirements and important authority for federal savings performance contracting.
NEEP Northeast Energy Efficiency Partnerships:
A regional nonprofit that develops market transformation, building, evaluation, and technology resources for energy-efficiency programs.
NEI Non-Energy Impacts:
Beneficial or adverse effects not captured as energy savings, considered in program evaluation and broader cost-effectiveness analysis.
NEMA National Electrical Manufacturers Association:
An industry association that publishes equipment standards and performance classifications relevant to motors, controls, lighting, and electrical products.
NFPA 70E National Fire Protection Association Standard 70E, Standard for Electrical Safety in the Workplace:
A key standard for electrical safe-work practices, shock protection, arc-flash risk assessment, and protective equipment.
NLC Networked Lighting Controls:
Connected lighting devices and software that coordinate scheduling, occupancy sensing, daylight response, dimming, and energy monitoring.
NMBE Normalized Mean Bias Error:
A statistical measure showing whether a baseline model systematically overpredicts or underpredicts observed energy use.
NMEC Normalized Metered Energy Consumption:
A whole-building savings method that uses metered consumption and normalization for weather and other relevant independent variables.
NTG Net-to-Gross:
A ratio used to adjust gross program savings for attribution effects such as free ridership and spillover.
O
OBF On-Bill Financing:
A financing model in which a utility or program administrator funds improvements and collects repayment through the customer’s utility bill.
OBR On-Bill Repayment:
A structure that uses the utility bill to collect payments for improvements financed by a third-party lender or capital provider.
OCx Ongoing Commissioning:
Continuous or periodic monitoring and optimization used to maintain building-system performance and prevent savings degradation.
OEM Original Equipment Manufacturer:
The company that produces equipment or components and provides product specifications, warranties, technical support, and approved replacement requirements.
O&M Operations and Maintenance:
The procedures, labor, and resources required to operate equipment reliably and preserve efficiency, service life, and project savings.
OpenADR Open Automated Demand Response:
An open communications specification for exchanging price and event signals between grid or program operators and customer energy-management systems.
P
P4P Pay for Performance:
A program or contract model that bases compensation partly or wholly on measured energy savings or delivered demand reductions.
PAC Program Administrator Cost Test:
A cost-effectiveness test comparing program-administrator expenditures with the avoided energy and capacity costs attributable to program savings.
PACE Property Assessed Clean Energy:
A financing mechanism that secures repayment for eligible building improvements through a property-linked assessment.
PAYS Pay As You Save:
A tariff-based model in which a utility funds eligible upgrades and recovers costs through a charge associated with the metered location.
PCT Participant Cost Test:
A cost-effectiveness test comparing a participating customer’s bill savings, incentives, tax effects, and other benefits with that customer’s costs.
PF Power Factor:
The ratio of real power to apparent power in an alternating-current system, affecting electrical capacity utilization and some customer charges.
PRISM Princeton Scorekeeping Method:
A weather-normalization method that uses utility billing data and degree-day relationships to estimate building energy consumption and savings.
PSC Public Service Commission:
A state-level regulatory body that may approve utility efficiency plans, demand-response programs, cost recovery, customer protections, and tariffs.
PTR Peak-Time Rebate:
A rate or incentive design that rewards customers for reducing electricity use during designated high-demand periods.
PUE Power Usage Effectiveness:
A data-center metric comparing total facility energy with the energy used by information-processing equipment, highlighting infrastructure overhead.
Q
QCI Quality Control Inspector:
A credentialed role responsible for independently checking residential weatherization work, documentation, health and safety, and installation quality.
QECB Qualified Energy Conservation Bond:
A U.S. tax-advantaged bond mechanism used to finance qualifying public energy-conservation projects and programs.
R
R² Coefficient of Determination:
A statistical indicator of how much variation in observed energy use is explained by a regression model.
RCx Retro-Commissioning:
Commissioning applied to an existing building to identify and correct operational, controls, maintenance, and system-integration problems.
ReCx Recommissioning:
Repeating commissioning on a previously commissioned building to restore performance after operational changes, equipment degradation, or control drift.
RESNET Residential Energy Services Network:
A standards and credentialing organization best known for residential energy ratings, energy modeling, and quality-assurance requirements.
RIM Ratepayer Impact Measure:
A cost-effectiveness test assessing whether a program could increase or decrease rates for customers who do not participate.
RMSE Root-Mean-Square Error:
A statistical measure of the typical magnitude of differences between modeled and observed energy consumption.
R-PACE Residential Property Assessed Clean Energy:
A residential financing mechanism that repays qualifying home energy improvements through a property assessment where authorized.
RTP Real-Time Pricing:
A retail rate structure in which electricity prices change frequently to reflect time-varying market or system conditions.
RTU Rooftop Unit:
A packaged heating, cooling, and ventilation system commonly targeted for controls, economizer, fan, and equipment-efficiency upgrades.
RUL Remaining Useful Life:
The estimated time an asset can continue to provide acceptable service, informing replacement timing, economics, and risk allocation.
S
SBC System Benefits Charge:
A regulated charge on utility customers used in some jurisdictions to fund efficiency, low-income, research, and other public-benefit programs.
SCT Societal Cost Test:
A cost-effectiveness test that considers broad societal costs and benefits, potentially including environmental and non-energy impacts.
SEC Specific Energy Consumption:
Energy used per unit of output, throughput, or service, commonly applied to industrial processes and production facilities.
SEER Seasonal Energy Efficiency Ratio:
A seasonal cooling-efficiency rating for certain air-conditioning and heat-pump equipment.
SEM Strategic Energy Management:
A structured, organization-wide approach combining executive commitment, data, operational practices, employee engagement, and continual improvement.
SEP 50001 Superior Energy Performance 50001:
A U.S. certification program that builds on an international energy-management standard and requires verified improvement in energy performance.
SEU Significant Energy Use:
An energy use identified as substantial or offering meaningful improvement potential and therefore prioritized within an organizational management system.
SHGC Solar Heat Gain Coefficient:
The fraction of incident solar radiation entering through glazing, used to evaluate windows, cooling loads, and daylighting tradeoffs.
SIR Savings-to-Investment Ratio:
The ratio of discounted project savings to discounted investment costs; values above one generally indicate life-cycle cost-effectiveness.
T
TAB Testing, Adjusting, and Balancing:
Field measurement and adjustment of air and water systems to achieve specified flows and support efficient, reliable operation.
TEDI Thermal Energy Demand Intensity:
Annual space-heating and cooling demand normalized by floor area, used to evaluate envelope and passive-design performance.
THD Total Harmonic Distortion:
A measure of waveform distortion that helps assess power-quality effects from variable-speed drives, lighting drivers, and other nonlinear loads.
TMY Typical Meteorological Year:
A representative hourly weather dataset used in building simulation, equipment sizing, and normalized performance analysis.
TOU Time-of-Use:
A rate design with predefined prices for different time periods, creating incentives to shift consumption away from expensive hours.
TRC Total Resource Cost Test:
A cost-effectiveness test comparing avoided energy-system costs with program and participant costs, regardless of who pays them.
TRM Technical Reference Manual:
A jurisdictional or program document specifying approved savings algorithms, input assumptions, measure lives, costs, and verification requirements.
TSB Total System Benefit:
A metric that monetizes the lifecycle energy-system value of efficiency or load flexibility, often reflecting when and where savings occur.
U
UCT Utility Cost Test:
A cost-effectiveness test comparing utility or administrator program costs with avoided supply, capacity, transmission, and distribution costs.
UESC Utility Energy Service Contract:
A contracting mechanism through which a serving utility arranges financing and implementation of energy improvements for a federal customer.
USGBC U.S. Green Building Council:
A nonprofit organization that develops green-building programs and credentials used in high-performance building projects.
V
VAV Variable Air Volume:
An air-distribution approach that varies airflow to match zone loads, creating opportunities for fan, ventilation, and control savings.
VFD Variable-Frequency Drive:
An electronic controller that adjusts motor speed and torque, often producing substantial savings on variable-load fans and pumps.
VRF Variable Refrigerant Flow:
A multi-zone heating and cooling technology that modulates refrigerant flow to match individual zone requirements.
W
WAP Weatherization Assistance Program:
A U.S. federal program that funds efficiency and health-and-safety improvements for income-qualified households through state and local delivery networks.