Options Flashcards
Option A - Retrofit Isolation Key Parameter(s) Measurement
Definition:
Savings are determined by field measurement of the key parameter(s), which define the energy consumption and/or demand of the EEM’s affected system(s).
Performance indicators may also be defined and measured to ensure the success of the project.
Measurements range from periodic short-term to continuous long-term, depending on the expected variations in the key parameter(s). Parameters not selected for field measurements are estimated values. Estimates can be based on historical data, manufacturer specifications, or engineering judgment.
Documentation of the source and justification of the estimated value is required. The plausible savings error arising from estimation rather than measurement is evaluated and is acceptable to stakeholders.
How Savings are calculated:
Calculation of baseline period energy and reporting period energy from periodic short-term energy measurements, or from periodic short- term or continuous measurements of key parameter(s) and from estimated values.
Routine and non-routine adjustments as required.
Key parameter(s) must be measured during both baseline and reporting period.
Typical Application:
A lighting retrofit where the change in power drawn by the lighting system is the most uncertain parameter and is measured, and secondly, lighting operating hours are estimated based on facility schedules and occupant behavior.
Notes: Multiple key parameters often exist, and selection of key parameters to measure is an important consideration.
Best Application:
The level of savings is low and cannot justify the cost of measurements needed for Option B or simulation for Option D.
Estimation of parameters may avoid possibly difficult non-routine adjustments when future changes are likely to happen that affect energy use within the measurement boundary.
Uncertainty created by estimations is acceptable.
Interactive effects are limited or easily estimated.
The continued effectiveness of the EEM can be assessed by simple routine re-testing or re- inspection of key parameters.
Key parameter(s) used to judge a project’s performance in computing savings can be readily identified.
Option B - Retrofit Isolation All Parameter Measurement
Definition:
Savings are determined by continuous field measurement of the energy consumption and/or demand or validated proxy variables and the related independent variables of the EEM affected system.
Measurements range from periodic short-term to continuous long-term, depending on the expected variations in the key parameters.
How Savings are calculated:
Determination of baseline period energy based on short-term or continuous measurements of baseline and reporting period energy, or on engineering computations using measurements of proven proxies of energy consumption or demand.
Routine and non-routine adjustments as required.
Typical Application:
Installation of a variable-frequency drive and controls to a motor to adjust pump flow. Measure electric power with a kW meter installed on the electrical supply to the motor, which reads the power demand every minute. In the baseline period, this meter is in place for a month and system testing was conducted to verify constant loading across a full range of operating conditions. The meter remains in place throughout the reporting period to measure energy consumption and demand.
Best Application:
The energy consumption of EEM can be isolated.
EEM impacts equipment with variable loads and variable operating hours. Baseline energy consumption within the measurement boundary is variable.
Interactive effects are limited or easily estimated.
The EEM affects more than one key parameter.
The EEM’s outcome will benefit from monitoring.
Meters for isolation purposes exist or will be used for other purposes such as operational feedback or tenant billing.
Measurement of the key parameters is less costly than simulation in Option D.
Option C - Whole Facility
Definition:
Savings are determined by measuring energy consumption and/or demand at the whole facility or sub- facility level, often using utility meter data.
Continuous measurements of the entire facility’s or sub- facility’s energy consumption and/or demand are taken throughout the baseline period and the reporting period.
How Savings are calculated:
Analysis of the whole facility or sub- facility baseline and reporting period energy data (e.g., utility meter) and independent variables.
Routine adjustments as required, typically using models based on regression analysis techniques.
Non-routine adjustments as required.
Typical Application:
Multifaceted energy management programs affecting many systems in a facility. Measure energy consumption and/or demand with the gas and electric utility meters for a twelve-month baseline period and throughout the reporting period.
Best Application:
An assessment of the energy performance of the whole facility is of interest rather than the individual EEMs.
There are many types of EEMs in one facility.
2 Both continuous and categorical variables may be included.
EEMs involve activities whose individual energy consumption and demand are difficult to measure separately.
Savings are large compared to the variance in the baseline and reporting period energy data.
Retrofit isolation techniques (Option A or B) are excessively complex and costly.
Significant future changes to the facility are not expected during the reporting period.
A system of tracking static factors can be established to enable possible future non-routine adjustment.
Reasonable correlations can be found between energy consumption or demand and independent variables.
Utility data or sub-metered energy data is available in frequent intervals.
Option D - Calibrated Simulation
Definition:
Savings are determined through simulation of the energy consumption and demand of the whole facility, or of a sub-system in the facility and comparing results with actual energy consumption and demand.
Simulation models are demonstrated to adequately model actual energy performance in the facility.
This option requires considerable skill in calibrated simulation and experience with the equipment and processes being modeled.
How Savings are calculated:
Actual energy consumption and demand and results from simulation model(s).
Energy consumption and demand from the simulation, calibrated with hourly, daily or monthly energy data. Energy sub-metering and metered performance data including processes may be used in further model calibration.
Non-routine adjustments as required.
Typical Application:
Multifaceted energy management programs affecting many systems in a facility but where no meter existed in the baseline period.
Energy consumption and demand measurement, after installation of natural gas, electric or other energy meters, is used to calibrate a simulation model.
Best Application:
Baseline period energy data are unavailable or unreliable, such as:
o New construction project
o Facility expansion needing to be assessed separately from the rest of the facility
o Centrally metered campus of facilities where no individual facility meter exists in the baseline period, but where individual meters will be available after EEM installation.
There are too many EEMs to assess using Options A or B.
The performance of each EEM will be estimated individually within a multiple EEM project, but the costs of Options A or B are excessive.
Interactions between EEMs are complex and significant, making the isolation techniques of Options A and B impractical
