Framework Flashcards
Why can’t energy use after installation of EEMs be based on a simple comparison?
The Adjustments term distinguishes proper savings reports from a simple comparison of cost or consumption before and after implementation of an EEM. Simple comparisons without such adjustments report only changes and fail to report the true performance of a project.
Measurement Boundary
The measurement boundary is used to isolate the equipment and related energy use which are impacted by the EEM(s) from those unaffected by the EEM(s). All energy used or generated within the boundary must be measured or estimated using meters at the measurement boundary. Note that energy flows from all energy sources crossing the measurement boundary should be evaluated, and those impacted by the EEM must be measured. Note that in some cases, such as on-site solar generation, energy may flow in reverse.
Types of measurement boundaries?
The two basic types of measurement boundaries used are Whole Facility and Retrofit Isolation. The type of measurement boundary selected generally aligns with one or more of the four IPMVP Options and impacts the granularity of the savings reported and the measurements required. The purpose(s) of the M&V reporting must be considered when selecting an Option.
Retrofit Isolation
Option A: Key parameter(s) measurement
Option B: All parameter measurement
If the purpose of reporting is to verify the savings from equipment affected by the energy efficiency project, a measurement boundary should be drawn around that equipment, and measurement requirements for the equipment within the boundary can then be determined. Energy consumption and/or demand may be directly measured or determined by direct measurement of key variables that can be reliably used to calculate demand or energy consumption. The approach used is a Retrofit Isolation Option
Whole Facility
Option C: Whole facility
Option D: Calibrated Simulation
If the purpose of reporting is to verify and/or help manage total facility energy performance or verify the savings from multiple EEMs with interactive effects, the meters measuring the supply of energy to the whole facility can be used to assess performance and savings. The measurement boundary, in this case, encompasses the whole facility. The approach used is Option C: Whole Facility
If the Baseline Period or Reporting Period data are unreliable or unavailable (e.g., new construction), energy data from a calibrated simulation model can be applied for either a portion or all of the facility. The measurement boundary can be drawn accordingly. The approach used is Option D: Calibrated Simulation
Baseline Period (measurement period 1/3)
The baseline period should:
Represent all operating modes of the facility or the equipment during a normal operating cycle. The period should span a full operating cycle from maximum energy consumption and demand to a minimum.
Include only time periods for which factors that impact energy use of the facility are known. These include independent variables and static factors (i.e., energy influencing factors).
o The extension of baseline periods backward in time to include multiple cycles of operation requires equal knowledge of factors that impact energy use throughout the longer baseline period to properly derive routine and non-routine adjustments after EEM installation.
Coincide with the period immediately before implementing the energy efficiency measures.
o Periods further back in time may not necessarily reflect the conditions existing before the retrofit and, therefore, may not provide a proper baseline for measuring the effect of just the EEM.
Support EEM planning.
o EEM planning may require the study of a longer or different time period than the one chosen for the baseline period.
Baseline Energy Data Considerations
Whole building energy consumption and demand can be significantly affected by weather conditions. Typically, a full year of monthly data is required to define a full operating cycle. If interval data (hourly or daily) are used, a full operating cycle may be captured in less than a year if the full range of weather conditions is included.
The energy consumption and demand of a compressed air system may only be governed by plant production levels, which vary on a weekly cycle. In this case, several weeks’ data may be all that is needed to define baseline performance across a full range of operating conditions.
The collection and documentation of static factors such as scheduled hours of operation can be critical to applying adjustments in the M&V reporting period.
Installation Period (measurement period 2/3)
The length of the installation period depends upon the project and EEMs. Measurements and site inspections during this period may be used to monitor for changes in static factors that could impact savings from the EEMs and necessitate the need for non-routine adjustments.
Depending on the M&V Option(s) and measurement boundary selected, reporting period measurements on individual EEMs may begin after operational verification is complete. In some instances, specific contractual provisions may be needed to accommodate staggered completion of EEMs over time. Installation periods vary by project and, in some cases, may include all or part of the reporting period (e.g., continuous improvement programs).
Reporting Period (measurement period 3/3)
The developer of the M&V Plan should recommend the length of the overall reporting period for the project over which measurements will be taken, and the period each saving report will cover. Energy data collected during this period will be compared to the baseline period energy to develop verified savings.
The reporting period should encompass at least one complete normal operating cycle of the equipment or facility to fully characterize the savings effectiveness in normal operating modes. The reporting period should encompass long-term performance monitoring for some projects, while other projects may cease reporting verified savings after a shorter measurement period (ranging from spot readings to measurements taken over one or several months). The length of any reporting period should be determined with due consideration of the life of the EEM(s), the likelihood of degradation of originally achieved savings over time, costs or resources required to perform M&V activities, and the purposes of ongoing savings reporting. The frequency and level of detail reported may change over time, if needed.
If the frequency of performance measurements after initial proof of savings are reduced, other on-site monitoring activities can be intensified to ensure savings remain in place and operational verification activities are repeated. The M&V Plan should specify when this represents a change in IPMVP Options. Regardless of the length of the reporting period, metering may be left in place to provide feedback of operating data for routine ongoing management purposes and to detect subsequent adverse changes in performance.
Measurements or verified savings from a past reporting period may not be used as a basis for assuming future savings.
Baseline Period Conditions
Baseline period conditions include details of the facility and systems before the implementation of Energy Efficiency Measure(s). These conditions must be well documented because they are a critical element of the M&V process and become unavailable once an EEM is implemented.
Data related to the systems and equipment impacted by the EEM(s), as well as the independent variables and static factors, need to be documented corresponding to the time period for which baseline energy consumption data are collected. The extent of the information required is determined by the planned EEM, selected M&V Option, measurement boundary chosen, and the energy influencing factors.
This information may include variables such as production data, ambient temperature, equipment or system operating pressures, or other variables collected through spot measurements, short-term or long- term metering, or site inspections.
Similarly, the prevailing facility conditions during the baseline period need to be documented. These conditions (i.e., static factors) are normally assumed to remain constant over the baseline, installation, and reporting periods. If static factors change and substantially impact the savings, the impact will have to be addressed using non-routine adjustments.
It is important to identify past and planned changes to conditions (i.e., static factors) that may affect the baseline or reporting period energy. Changes may include any number of items such as an increase in occupancy levels, adding a shift, changing the size of the facility served, adding equipment, or increasing lighting levels. This information can impact the selected measurement boundary and help plan for non- routine adjustments
Static Factor examples
Examples of static factors are multiple and may include:
Facility size installed equipment and systems.
Occupancy details of type, occupancy density, equipment loads, and equipment run times.
Operating conditions (e.g., equipment control sequences and set points, lighting levels, ventilation levels) for each operational mode and season.
What are the methods of adjustment?
Routine Adjustments:
Any energy influencing factors expected to change routinely during the reporting period which have a statistically significant impact on energy use in the baseline period and are expected to remain variable in the reporting period should be considered to define the routine adjustment methodology or model. Influencing factors such as weather or production volume should be evaluated for statistical significance to energy consumption or demand.
Adjustment techniques may be as complex as using several multiple parameter equations which correlate energy with one or more independent variables or as simple as applying an established energy value to an EEM known to be at constant load as indicated by a proxy variable (e.g., fan energy consumption during heating mode as indicated by recorded operating parameters). Valid mathematical techniques must be used to derive the adjustment method for each M&V Plan.
Non-Rountine Adjustments:
For those energy influencing factors that are not usually expected to change (e.g., the facility size, the design, and operation of installed equipment, the number of weekly production shifts, or the type or number of occupants), the associated static factors must be monitored for change throughout the reporting period.
When a change to one or more static factors which significantly impacts energy use within the measurement boundary is identified, this becomes a potential non-routine event. When analysis of the non-routine event indicates a significant impact on the magnitude of energy savings, this then warrants making a non-routine adjustment.
Non-routine adjustments can potentially have a significant impact on reported savings; the rationale and calculation for non-routine adjustments should be agreed upon between the parties and documented.
What are the savings accounting approaches?
Avoided Energy Consumption or Demand:
Typically under conditions of the reporting period
Requires routine adjustments to the baseline period energy to reflect reporting period conditions, OR less commonly, routine adjustments are made to the reporting period energy to reflect baseline period conditions.
Depends upon the reporting period’s operating conditions or baseline period’s operating conditions. Even though energy can be properly adjusted using independent variables such as weather or production, verified savings reported depend upon the actual energy use and independent variable data collected during the period selected as the basis for adjustment.
Normalized Energy Savings:
Under fixed or normal conditions
Normalized energy savings use conditions other than those of the reporting or baseline periods as the basis for adjustment. The conditions may be those of an agreed-upon representative period or a typical, average or normal set of conditions as the basis of adjustment. Adjustments to a fixed set of conditions such as typical meteorological year (TMY) weather data provide a type of savings called normalized energy savings. In this method, the reporting period energy and the baseline period energy are adjusted from their actual conditions to the common fixed or normal set of meaningful conditions.
Require routine adjustments to the reporting period energy and the baseline period energy to a fixed set of conditions that are established once and are not changed.
Can be directly compared with savings from other time periods and EEMs where savings are predicted under the same set of fixed conditions.
Can only be reported after a full cycle of reporting period operating conditions so that the mathematical correlation between reporting period energy and operating conditions can be derived.
What is operational verification?
Operational verification consists of a set of activities intended to ensure that the EEM is installed, commissioned, and performing its intended function. Confirmation that Energy Efficiency Measures are installed and operating as per the design intent and have the potential to perform and generate savings is required. This may involve inspections, measurements, functional performance testing, and/or data trending with analysis.
While operational verification activities may not be the responsibility of the M&V agent, the operational verification activities proposed and the party responsible should be documented in the M&V Plan and results reported. Developing the operational verification requirements provides an opportunity to review the engineering design to ensure that the savings estimates are realistic and achievable.
Does operational verification assess savings potential?
Operational verification serves as a low-cost initial step for assessing savings potential and should be conducted prior to other post-installation saving verification activities. Operational verification can be integrated with commissioning efforts. Both data collection and analysis tasks can be used to support the M&V quantitative efforts and determine the proper performance of the EEMs.
