AEE CMVP study materials
AEE CMVP study resources

AEE CMVP cheat sheet

AEE CMVP · Keep the key ideas within reach.

Quick reference

Basis for Adjustment

  • Adjustments normalize savings for changes in conditions (weather, occupancy, production) independent of the ECM.

  • Routine adjustments: expected and predictable changes (e.g., weather, production volume) handled via a model.

  • Non-routine adjustments: unexpected or one-time changes (e.g., building addition, equipment replacement) handled ad hoc.

  • The adjusted baseline is the baseline energy use modified by both routine and non-routine adjustments.

  • Savings = (Baseline Energy − Reporting-Period Energy) ± Adjustments.

  • IPMVP requires that the baseline period be representative of normal operating conditions and that adjustments be based on measured or documented data.

  • Adjustment methods include: fixed-factor, algebraic, or model-based (e.g., regression) approaches.

  • Uncertainty of adjustments should be quantified and reported.

Quick reference

Fundamental Performance Verification Approaches

  • Four IPMVP M&V options: A (Retrofit Isolation: Key Parameter Measurement), B (Retrofit Isolation: All Parameter Measurement), C (Whole Facility), D (Calibrated Simulation).

  • Option A: Some parameters measured, others estimated; estimates must be justified and documented.

  • Option B: All parameters affecting energy use are measured continuously or periodically.

  • Option C: Whole-building utility meter data used; best for multi-ECM projects or when savings >10% of total baseline.

  • Option D: Calibrated simulation used when baseline data are unavailable or for new construction.

  • Selection depends on: project size, complexity, data availability, and required accuracy.

  • Each option has different cost and accuracy trade-offs; higher accuracy generally costs more.

  • M&V costs typically 1–10% of project cost; should be proportional to savings uncertainty.

Quick reference

Retrofit Isolation Approach to M&V

  • Options A and B focus on individual ECMs, isolating their energy use from the rest of the facility.

  • Option A (Key Parameter Measurement): measures parameters with significant impact or high variability; estimates others.

  • Option B (All Parameter Measurement): measures all parameters affecting the ECM's energy use, often with dedicated meters.

  • Use when ECM savings are large relative to whole-building use, or when ECMs are independent and can be isolated.

  • Baseline and reporting-period measurements must be taken at the same boundaries and with same metrics.

  • Option A estimates must be based on evidence (e.g., manufacturer data, spot measurements) and documented.

  • Option B is more accurate but costlier; suitable for complex or high-uncertainty ECMs.

  • Common applications: lighting retrofits, variable frequency drives, HVAC equipment replacement.

Quick reference

Whole Facility Approach to M&V

  • Option C uses whole-building utility meters (electric, gas, etc.) to measure total facility energy use.

  • Best when savings are >10% of baseline whole-facility energy use and multiple ECMs are implemented.

  • Requires continuous utility data for baseline and reporting periods; often uses regression models with weather.

  • Less expensive per ECM but cannot isolate individual ECM savings without additional sub-metering.

  • Adjustments use whole-building regression models (e.g., change-point models) to account for weather and other variables.

  • Uncertainty analysis is critical; savings must be statistically significant above model uncertainty.

  • Not suitable for small savings (<5-10%) due to meter and model noise.

  • Can be combined with Option A/B for verification of individual ECMs.

Quick reference

M&V Planning

  • M&V Plan is a document that outlines the M&V approach, responsibilities, data collection, and reporting.

  • Key elements: project description, ECM list, M&V option selection, baseline definition, measurement boundaries, adjustment method, data management, reporting schedule, budget.

  • Develop M&V Plan early, ideally during project design, to ensure data collection and metering are included.

  • The plan should specify the baseline period, reporting period, and frequency of measurements.

  • Stakeholders (owner, ESCO, verifier) should agree on the plan before implementation.

  • The plan should include a description of the uncertainty analysis and how savings will be verified.

  • Update the plan if significant changes occur during the project.

  • M&V Plan is often a contractual requirement in performance contracts.

Quick reference

Savings Reporting

  • Savings reports must include: baseline energy, reporting-period energy, adjustments, savings, and uncertainty.

  • Report both energy and cost savings; specify units and currency.

  • Clearly state the M&V option used and any deviations from the M&V Plan.

  • Include a discussion of non-routine adjustments and their impact.

  • Present results in tables and graphs for clarity; include raw data or references.

  • Report uncertainty at a stated confidence level (e.g., 90%).

  • Include a comparison with expected savings and explain discrepancies.

  • Reports should be transparent, reproducible, and follow a consistent format.

Quick reference

Metering and Considerations

  • Meter accuracy: Class 1 (high accuracy) vs. Class 2 (lower); choose based on required precision.

  • Metering duration and interval: continuous (15-min intervals) vs. periodic (monthly) based on ECM variability.

  • Install meters to measure only the ECM's energy use; avoid including unrelated loads.

  • Calibrate meters regularly; document calibration dates and results.

  • Consider temporary vs. permanent metering; temporary for short-term, permanent for continuous verification.

  • Data quality: check for gaps, outliers, and meter drift; use data validation procedures.

  • Metering cost should be balanced against the value of accuracy; over-metering can be uneconomical.

  • For Option A, spot measurements or short-term monitoring may suffice for estimated parameters.

Quick reference

Modeling Concepts and Application

  • Regression models relate energy use to independent variables (e.g., weather, occupancy, production).

  • Common models: change-point (heating/cooling), polynomial, and time-of-week models.

  • Model selection based on data patterns and goodness-of-fit (R², CV(RMSE), t-statistics).

  • CV(RMSE) < 15% (or 10% for Option C) is often used as a calibration criterion.

  • Use separate models for baseline and reporting periods if conditions changed significantly.

  • Avoid extrapolation beyond the range of baseline data; use non-routine adjustments if needed.

  • Model uncertainty should be propagated to savings uncertainty.

  • Validate models with independent data (e.g., hold-out sample) when possible.