AEP - C3 - Week 2 Slides

8/17/2019 AEP - C3 - Week 2 Slides

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CERTIFICATE PROGRAM

Developed by:

With generous support from:


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MANAGING TO PERFORMANCE TARGETS:

PART 2

WEEK 2


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WEEK 2: LEARNING OBJECTIVES

Comprehend the major goals and methods of performance assurance in the

energy field, and appreciate the relationship between performance

assurance and effective energy management.

Develop a comprehensive Energy Management Program based on familiarity

with the range of approaches and technologies

Demonstrate an understanding of metering, measurement and performance

data

Maximize the opportunities made possible by modern control systems, data

harvesting and monitoring

Understand how to implement Active Energy Management strategies,remedial actions for buildings that do not meet performance targets


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WEEK 2: READINGS

Required Readings:

1. The Energy Management Handbook , Chapter 2: Effective Energy

Management

2. CUNY BPL Building Performance Toolkit (website)

3. Monitoring, Targeting and Reporting: A Pathway to ContinuousImprovement in Energy Management . Wallace/Greenwald


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PERFORMANCE ASSURANCE


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DEVELOPING AN ENERGY BUDGET

Statistical manipulation of historical data

How much energy has been used over an observed period?

How does a given year’s usage compare to a typical period?

Caveat: Without additional context, historical data cannot provide

much insight into the meaning of past usage.

Engineering models

Models can be used to develop thorough energy balance

calculations that overcome the lack of detail from historical data.

The combination of historical data and present use models can helpto determine the amount of energy that will be required, and

where savings may be achieved.

Source: Patrick Crittenden, University of Technology, Sydney.


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MEASURING ENERGY SAVINGS

The key metric of energy efficiency programs is energy savings.

Savings can’t be directly measured; they represent the absence of energy use.

Instead, we estimate the impact of energy efficiency measures by comparing

energy use and demand before and after implementation of an energy

efficiency program, making adjustments for changes in conditions.

If other factors cannot explain any energy savings, then the lowered demand

is after implementation is presumably due to success of the energy efficiency

measures.

Source: “Model Energy Efficiency Program Impact Evaluation Guide,” US Environmental Protection Agency.


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SOURCES OF ENERGY-USE INFORMATION

Energy bills

Basic meter readings

Special meters that isolate an ECM,

a particular piece of equipment, or

a portion of a facility

Measurement of proven proxies

(e.g., ratio of fuel used to work

done, etc.)

Computer simulations

Can you think of any others?

Analog Home Electricity Meter.

(Source: Wikimedia Commons)



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ENERGY ACCOUNTING

Equation

Energy Savings = (Baseline Energy – Reporting-Period Energy) ±

Routine Adjustments ± Non-Routine Adjustments

Factors

a) Reporting Period Energy Use – Actual energy consumption

after program is implemented.

b) Baseline Energy Use – Consumption estimated to have

occurred before program was implemented; chosen to represent

normal operations; BAU energy use.

c) Adjustments – Account for external factors, such as weather,

occupancy and operating hours



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ENERGY ACCOUNTING FACTORS:

BASELINE PERIOD

Baseline: Consumption to have occurred before energy efficiency

measure was implemented.

The data used should:

Represent all operating modes of facility

Span a full operating cycle, from maximum to minimum energy use(e.g., a full year, one month, one week)

Include only time periods for which all fixed and variable energy-

governing facts are known about the facility

Coincide with period immediately before commitment to undertake

retrofit, to provide a proper baseline for measuring effects



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Reporting Period: Consumption occurring in an equivalent period,

after energy efficiency program has been implemented.

The data used should:

Span a full operating cycle, from maximum to minimum energy

use

Be sure to include all fixed and variable energy-governing factsthat are known about the facility

Coincide with the period just after commitment to changes, in

order to provide a proper baseline for measuring effects

Consider the life of the ECM and the likelihood of degradation over

time of originally achieved savings



REPORTING PERIOD


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Routine adjustments

Factors expected to vary during a typical reporting period

Weather

Production volume

Operating Hours

Non-routine adjustments

Factors that may or may not vary (but which must be monitored for

variations/changes throughout reporting period)

Facility size

Design and operation of installed equipment

Number of occupants



ADJUSTMENTS


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TYPES OF SAVINGS: AVOIDED ENERGY USE

Avoided energy use (or avoided costs)

Savings in reporting period, relative to expected energy use

without the enacted energy conservation measures.

Degree depends on operating conditions during Reporting Period

Can not be directly compared with savings predicted under

baseline-period conditions

Equation

Avoided Energy Use (or Savings) = (Adjusted-Baseline Energy –

Reporting-Period Energy) ± Non-Routine Adjustments of Baseline

Energy to Reporting Period Conditions



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TYPES OF SAVINGS: NORMALIZED SAVINGS

Normalized Savings Not affected by reporting-period conditions

Fixed set of conditions is established once and doesn’t change

May be directly compared with savings predicted under same

conditions

Reported after a full cycle of Reporting Period use

Conditions other than those of reporting period may be used as the

basis for adjustment (e.g., conditions of baseline period, other

arbitrary period, or an average or “normal” set of conditions)

Equation Normalized Savings = (Baseline Energy ± Routine Adjustments ± Non-

Routine Adjustments) – (Reporting-Period Energy ± Routine

Adjustments ± Non-Routine Adjustments)



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WHAT IS COMMISSIONING?

“Existing building commissioning, or retrocommissioning, applies a

systematic process for improving and optimizing a building’s operations

and supporting those improvements with enhanced documentation andoperator training.”

- Building Commissioning Association


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WHY COMMISSION

NEW BUILDING SYSTEM PROJECTS?

Commissioning new systems helps ensure that they will:

Meet energy efficiency goals

Meet operational requirements

Provide reliability, functionality, and durability

Operate as intended

Meet any additional requisite specifications

Seven World Trade Center, NYC.(Source: Wikimedia Commons)

Source:

http://www1.eere.energy.gov/femp/pdfs/

commissioning_fed_facilities.pdf , p. 6

http://www1.eere.energy.gov/femp/pdfs/commissioning_fed_facilities.pdfhttp://www1.eere.energy.gov/femp/pdfs/commissioning_fed_facilities.pdfhttp://www1.eere.energy.gov/femp/pdfs/commissioning_fed_facilities.pdfhttp://www1.eere.energy.gov/femp/pdfs/commissioning_fed_facilities.pdf


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DEFINING KEY PERFORMANCE INDICATORS

Key Performance Indicators (KPIs) – Goals in the energy management planare converted into key performance indicators (KPIs) to be measured and

tracked.

Appropriate KPIs:

1. Are defined well in advance of any data collection

• Must determine the scope of data collection activities

2. Provide the foundation required to determine which data to collect,

how often to collect it, and how to present it.

3. Must support assumptions that are carefully stated to clarify

exactly what is going to be measured.

4. Can be expanded into levels of additional detail to help understand

the driving behavior of the defined performance metric.

To determine which measurement details to highlight:

Understand the underlying drivers of the performance metric

Know which details will give energy mangers the information they need to

correct deviations from target goals



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DATA COLLECTION: SCOPE

Data collection systems should be designed to capture just the right

amount of data required (not too much, not too little) to accomplish one’s

primary goals. Adding extraneous measurements “just in case they’re

needed” usually just leads to unnecessary cost and effort.

T.M.I.?

(Photo: Tom Ventura, via Wikimedia Commons.)



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DATA COLLECTION: TYPES OF DATA

Two major types of data:

• Static Data, such as facility floor space and equipment ratings, is

inherently consistent. It is often collected as part of an initial

energy audit and typically used to normalize measurements for

benchmark comparisons.

• Dynamic Data, such as energy consumption and externaltemperature, is inherently changing. It needs to be collected at

regular intervals and processed to generate the desired

performance metrics.



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• Potential Data Sources

• Energy consumption from:

• Energy bills

• “Shadow” metering

• Sub-meters

•

Existing automation systems

• Temperature Data from:

• Publications

• Live, online sources

• Local measurements

•

Existing automation systems

Image adapted from work by Ranjithsiji,

via Wikimedia Commons.

DATA COLLECTION: POTENTIAL SOURCES



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BASIC MODELING

Basic models:

1. Critical step in constructing the Key Performance Indicators

(KPIs)

• KPIs signal the impact of Energy Conservation Measures (ECMs).

2. Requires accurately intuiting relationships between energy

consumption data and certain variables (e.g., occupancy rates,temperatures) to isolate the factors that are the primary drivers

of consumption; then testing those hypotheses.

3. The approach is typically comprised of the following steps:

A. The researcher selects a baseline period and identifies a primary

driver by analyzing historical data

B. A baseline model of energy vs. the primary driver is created and

tested.

C. A correlation is sought between energy and driver usage

D. ECMs are applied to the driver activity, and one or more target

models are created to track the resulting energy performance



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2. ENERGY MONITORING,TARGETING, & REPORTING


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ENERGY M.T.&R.: KEY ACTIVITIES

Energy Monitoring

Involves the collection and analysis energy use data.

Targeting

Requires identifying and defining energy consumption goals.

Reporting

Consists of sharing information in ways that enable:

• Ongoing management of energy use

• Achievement of reduction targets

• Verification of cost and energy savings



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WHY ESTABLISH MT&R PROCEDURES?

Analyze historical energy performance

Set energy reduction targets

Control current energy performance

Project future energy budgets

Wind Farm. (Source: Jurgen, via Wikimedia Commons)



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WHAT ARE THE OBJECTIVES OF MT&R?

Improved budgeting and

forecasting

Improved product/service costing

Tracking and verification of energy

efficiency retrofits

Opportunities for improved O&M

practices

Chronograph. (Source: Rama, via Wikimedia Commons)



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WHAT FACTORS ARE INVOLVED IN

ENERGY MT&R?

1. Cumulative sum of difference analysis (CUSUM)

• Statistical technique that is the cornerstone of MT&R; analysis ofthe variance between energy consumption predicted by anenergy performance model (EPM) and the actual measuredconsumption.

2. Energy cost center (ECC)

• Organizational basis for MT&R; a unit for which energy use maybe measured along with other factors that influence energyconsumption (e.g., single building in a portfolio, major energyconsuming system such as the heating plant).

3. Units of measure

• Must measure data for all energy forms in the ECC; should be

recorded in physically measured units (e.g., gallons, litres,therms, kWh, ft 3).

4. Independent variables

• e.g., operating hours, occupancy schedules, degree days.



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ENERGY MT&R PROCESS

Measurement ofenergy consumption

over time

Measurement ofindependent

variables

Development of anenergy performance

model (EPM)

Historical analysisSetting performance

targets

Frequentcomparison of

actual consumptionto targets

Reporting ofconsumption andtarget variances

Savings verification



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3. DEVELOPING AN ENERGYPERFORMANCE MODEL


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HOW TO DEVELOP

AN ENERGY PERFORMANCE MODEL

Three methods:

1. Previous year’s data

• Using last year’s data to predict this year’s consumption; when

there are no significant factors of influence

2. Regression analysis

• Statistical approach based upon historical consumption and

factors of influence; most common method for a basic system

3. Simulation model

• Using computer models to simulate energy consumption



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HOW DO YOU SET PERFORMANCE TARGETS

FOR YOUR EPM?

Four methods:

1. Looking at periods of peak performance.

2. Eliminating the highest or least efficient points from the data set and

using what remains as a target range.3. Defining targets by using the best historical performances as the

goals (instances well below the regression line).

4. By assessing the base and incremental loads to identify specific

actions that can be taken to reduce them.



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WHAT IS ENERGY SYSTEMS MAINTENANCE?

Energy systems maintenance (ESM) is an integral part of an energymanagement program that measures energy consumption and compares it to

company goals or an established standard of energy consumption.

Purpose:

Keep equipment from failing

Help keep energy costs within reason

Help prevent excess capital expenditures

Address safety/compliance issues

Challenge:

Need to adjust consumption data for independent variables, including:

Changes in weather (e.g., degree days, over time, place to place)

Varying levels of activity (e.g., occupancy)

Changes in space utilization (e.g., changes in conditioned floor

space)



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WEEK 2: IN-CLASS EXERCISES

1. Describe some of the ways in which energy savings are calculated, and

what role such calculations could play in the context of performance

assurance.

2. What are the three major methods for developing an energy

performance model (EPM)? Briefly discuss the steps involved in setting

targets, and explain why they may be varied from one site to another.


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WEEK 2: HOMEWORK

Consider the Imperial building again. Briefly describe the independentvariables that you would take into account when determining the work

loads that are being placed on its energy system components. For

example, think about the varying intensities of use by time of day, season,

or economic conditions. Also consider how the specific activities that are

conducted within the building may have a unique impact on its patterns

of energy needs.

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AEP - C3 - Week 2 Slides

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