AEE CMVP key terms

A routine or non-routine change made to baseline or reported energy use so savings reflect current conditions rather than the conditions that existed when the baseline was set.

A predictable, regularly applied correction to baseline energy use driven by variables such as weather, production volume, or occupancy, typically calculated with an agreed mathematical method each reporting period.

A correction applied when an unforeseeable change alters energy use, such as a facility addition, major equipment swap, or occupancy shift, requiring engineering judgment and often negotiated documentation before savings are reported.

The pre-retrofit period of energy use, demand, and operating conditions against which post-installation performance is compared to compute savings.

The defined span of time, usually twelve consecutive months, selected to represent typical pre-retrofit operations and used to develop the baseline model or average.

The defined interval after retrofit installation over which actual energy use is measured and compared with adjusted baseline values to determine savings.

A measurable factor such as outdoor temperature, degree-days, or production output that drives energy use and is used in a model to adjust the baseline to current conditions.

A condition or driver expected to remain essentially unchanged between baseline and reporting periods, such as building size or installed equipment capacity, so no routine adjustment is needed for it.

Changes in energy use in one system caused by a retrofit in another, such as reduced lighting heat load lowering space heating or raising cooling energy, which should be accounted for in the measurement boundary.

Retrofit isolation with key parameter measurement, where the savings-determining parameters are measured continuously or periodically while others are stipulated by agreement, often used for lighting or fixed-load retrofits.

Retrofit isolation with all parameter measurement, where every parameter affecting the savings calculation is measured for the full reporting period, suited to variable-load measures with significant uncertainty.

Whole facility metering, where savings are determined from utility meter data for the entire building or site, with adjustments from a baseline model, appropriate when savings are large relative to total use.

Calibrated simulation, where a computer model of the facility is calibrated to measured baseline data and used to estimate savings, useful when metering is impractical or multiple measures interact strongly.

A measurement boundary limited to the equipment or system affected by a single energy conservation measure, isolating its energy use from the rest of the facility.

The defined physical or logical envelope within which energy flows are measured or estimated for savings determination, which must be documented and applied consistently across baseline and reporting periods.

A parameter value agreed by the parties rather than measured, permitted under Option A for factors that are well understood and unlikely to change, and documented in the M&V plan.

Use of the main utility meters serving an entire building or site to determine total energy use for savings calculations, capturing all measures and their interactions together.

A building energy model adjusted until its predicted energy use closely matches measured utility data for a known period, then used to estimate savings under defined conditions.

The iterative process of tuning simulation inputs so model output statistically matches measured energy data, judged with metrics such as mean bias error and coefficient of variation of root mean square error.

A document written before construction that defines the measurement boundary, baseline, metering approach, adjustment method, reporting format, and responsibilities for verifying savings.

The difference between adjusted baseline energy use or cost and actual reporting-period energy use or cost, expressed as avoided consumption rather than a simple before-and-after subtraction.

The monetary value of energy not consumed because of a retrofit, calculated using the applicable tariff or rate structure and reported alongside physical energy savings.

Savings recalculated to a common set of conditions, such as a typical weather year or standard production level, so results from different periods or projects can be compared fairly.

Reduction in peak electrical demand (kW) achieved by a measure, determined from interval or peak-interval data and often valued separately from energy (kWh) savings under the tariff.

Documented assessments of metering accuracy, completeness, and reliability that support the credibility of reported savings and are typically recorded in the M&V plan and reports.

The portion of an M&V plan specifying which meters, sensors, and data loggers are installed, where, at what interval, and how data are validated and stored.

Energy measurements recorded at fixed short time steps, such as 15-minute or hourly readings, enabling load-shape analysis, demand determination, and time-of-use savings evaluation.

Ongoing recording of a parameter throughout the reporting period, as opposed to spot or short-term measurement, providing the strongest evidence for savings under retrofit isolation options.

Measurement conducted for a limited period, often used to establish load shapes or operating patterns that are then extrapolated, with the extrapolation method documented in the M&V plan.

A statistical equation relating energy use to one or more independent variables, commonly used to adjust baseline energy use to reporting-period conditions.

A normalized measure of how well a model fits measured data, computed as the root mean square error divided by the mean measured value, with lower values indicating better fit.

A statistic describing the proportion of variation in measured energy use explained by the regression model, used to judge whether the model captures the dominant drivers.

The range within which true savings are expected to lie, arising from metering error, sampling, modeling error, and unknown variables, and typically reported alongside the savings estimate.

The modeled or averaged relationship between energy use and its drivers during the baseline period, used as the reference for computing adjusted savings in later periods.

A specific retrofit, equipment change, or operational practice installed to reduce energy use or cost, and the unit around which the measurement boundary is usually drawn.

An agreed pattern of energy use over time, based on engineering estimates or prior data, used in place of continuous metering when measurement is impractical or uneconomic.