Best Practice Guide

Food and Beverage Growers and Processors

Planning an Energy Program

Measurement and Verification

A measurement and verification (M&V) plan is a set of agreed-upon metrics for an energy project that are used to establish baseline performance as well as to verify actual energy savings. In other words, the M&V plan defines precisely what "energy savings" means for energy efficiency or energy conservation projects. In contractual performance guarantees, M&V plans are particularly useful because they set clear, well-defined expectations between the building owners and the energy service company (ESCO). M&V plans also help to increase the level of confidence of financiers that an energy project will result in energy cost savings sufficient to fulfill debt obligations, which can make it easier to secure outside financing.

The U.S. Department of Energy, recognizing significant potential for energy efficiency investment, began in 1994 to work with industry to develop a set of best practices for M&V. This work led to the establishment of the International Performance Measurement & Verification Protocol (IPMVP). The latest version of the IPMVP, revised in 2002, includes input from a global network of professionals, including national organizations from 16 countries and hundreds of individual experts from more than 25 nations.

The IPMVP is used throughout the United States and the world to help standardize concepts and options for M&V of energy and water savings. The State of California has incorporated the IPMVP into State energy performance contracting and energy efficiency programs. The IPMVP is also consistent with the American Society of Heating, Refrigerating, and Air-Conditioning Engineers' (ASHRAE) draft Guideline 14P Measurement of Energy and Demand Savings and the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) certification program. Almost all performance-contracting firms adhere to the IPMVP.

The IPMVP describes four broad M&V options:

  1. Partially Measured Retrofit Isolation - only the building systems upgraded or retrofitted are measured and verified. Some of the parameters specified under the M&V plan are stipulated, that is, these parameters are given without measuring to verify accuracy. Operating hours of equipment, for example, can be stipulated based on historical data. However, the impact of potential errors made when stipulating parameters should not have a significant impact on calculations of energy savings. In general, stipulation is cheaper than measurement.
  2. Retrofit Isolation - only the building systems upgraded or retrofit are measured and verified. No stipulation is used. Measurements may be short-term or continuous throughout the post-retrofit period.
  3. Whole Facility - measurement is made at the whole building level. This option is best for cases where there is a high degree of interaction between installed energy measures or between these measures and other building systems. Measurements may be short-term or continuous throughout the post-retrofit period.
  4. Calibrated Simulation - savings are determined through simulation of energy use, either at the system level or the whole building level. Simulations are calibrated with hourly or monthly utility billing data and/or end-use metering. Because simulation routines must demonstrate adequate model accuracy of actual energy performance, a considerable skill in calibrated simulations is required. This option is usually limited to cases where energy savings cannot be isolated and where baseyear or post-retrofit data for the whole facility is missing or unreliable.

Calculating Energy Savings

Calculating Energy Savings

Energy Savings = Baseyear Energy Use - Post-Retrofit Energy Use ± Adjustments

"Adjustments" bring energy use in the two time periods to the same set of conditions. Adjustments include changes to parameters, expected or unexpected, such as weather, season, occupancy levels, equipment loads, or equipment deterioration.


Resources

International Performance Measurement & Verification Protocol: Concepts and Options for Determining Energy and Water Savings, Vol. 1. Revised March 2002.

California Energy Commission, Guide to Preparing Feasibility Studies for Energy Efficiency Projects, February 2000.