Fundamentals of energy audit

Dr. Murugananth Gopal Raj
Prof. & Head – EEE Dept.,
Ahalia School of Engineering & Technology,
Palakkad – 678557

What is energy audit?
Need for energy audit
Goal of energy audit
Stages of Audit
Types of Audit
Preliminary Energy Audit
Targeted Energy Audit
Detailed Energy Audit
Energy Audit Instruments
Dr. Murugananth Gopal Raj, ASET, Palakkad
ABCD…. Of Energy Audit

Energy audit - a strategic element - REDUCE ENERGY COSTS
and MANAGE ENERGY CONSUMPTION
Examine THE STATE OF ENERGY-USING EQUIPMENT
Take necessary MEASURES to replace any other repair or
improvement and reduce energy losses
What is Energy Audit?

An inspection survey
An analysis of energy flows for energy
conservation in a building
Include a process or system to reduce the
amount of energy input into the system
without negatively affecting the output
Includes alternative means and methods
for achieving energy savings
Energy Audit

Energy Audit
Energy Audit
As per the Energy Conservation Act, 2001, Energy
Audit is defined as "the verification, monitoring and
analysis of use of energy including submission of
technical report containing recommendations for
improving energy efficiency with cost benefit analysis
and an action plan to reduce energy consumption".

Goal of Energy Audit
• To achieve and maintain optimum energy
procurement and utilization throughout the
organization
• Minimize energy costs / waste without affecting
production & quality
• Minimize environmental effects
Goal of Energy Management

Operating expenses for an industry
• Energy (electrical and Thermal), labour and materials
Savings potential is higher in energy
Energy management – finds strategic area to reduce cost
Energy audit helps to
• Understand the ways energy and fuel are used
• Identify the area where waste can occur
• Find the scope for improvement
Need for Energy Audit

• Objective - Determine ways to reduce energy
consumption per unit of product output or to lower
operating costs.
• Energy Audit provides a " bench-mark" (Reference
point) for managing energy in the organization and
also provides the basis for planning a more effective
use of energy throughout the organization.

Stages of Energy Audit

Depends on
• Function and type of industry
• Depth to which final audit is needed
• Potential and magnitude of cost reduction desired
Types of Energy Audit

Energy Audit
Preliminary or
Walk-through
Audit
Targeted Audit Detailed Audit
Types of Energy Audit

Exercise to
• Establish energy consumption in the organization
• Estimate the scope for saving
• Identify the most likely (and the easiest areas for attention)
• Identify immediate (especially no-/low-cost) improvements/ savings
• Set a 'reference point'
• Identify areas for more detailed study/measurement
• Uses existing or easily obtained data
Preliminary Energy Audit

Targeted Energy Audit
• Based on outcome of preliminary audit results
• Provide data and detailed analysis on specified target projects
• Ex: can concentrate on lighting system or boiler system or
compressed air system to bring out energy savings
• Involved detail study on target areas with analysis of energy flows
and costs associated with the targets

A comprehensive audit provides a detailed energy project implementation plan for a
facility, evaluates all major energy using systems
Offers the most accurate estimate of energy savings and cost
Considers the interactive effects of all projects, accounts for the energy use of all
major equipment, includes detailed energy cost saving calculations and project cost
Key elements is the energy balance
Based on an inventory of energy using systems, assumptions of current operating
conditions and calculations of energy use
Estimated usage is compared to utility bill charges
Detailed Energy Audit

Carried out in 3 Phases
Phase – I : Pre-Audit Phase
Phase – II: Audit Phase
Phase – III: Post-Audit Phase
Detailed Energy Audit

10 Steps Methodology for Conducting Detailed
Energy Audit
Step
No.
Plan of Action Purpose / Results
Phase I – Pre-Phase Audit
1 Plan and organize
Walk through Audit
Informal Interview with
Energy Manager, Production
/ Plant Manager
Resource planning, Establish/organize an Energy audit
team
Organize Instruments & time frame
Macro Data collection (suitable to type of industry.)
Familiarization of process/plant activities
First hand observation & Assessment of current level
operation and practices

Energy Audit
Step
No.
Phase I – Pre-Phase Audit
2 Conduct of brief meeting /
awareness programme with
all divisional heads and
persons concerned (2- 3 hrs.)
Building up cooperation & rapport
Orientation, awareness creation
Issue questionnaire tailored for each
department

Energy Audit
Step
No.
Phase II – Audit Phase
3 Primary data
gathering, Process
flow diagram, Energy
utility diagram
Historic data analysis, Baseline data collection
Prepare process flow charts
All service utilities system diagram (Example: Single line
power distribution diagram, water, compressed air & steam
distribution)
Prepare process flow chart
Design, operating data and schedule of operation
Annual Energy Bill and energy consumption pattern (Refer
manual, log sheet, name plate, interview)

Energy Audit
Step
No.
Plan of
Action
Purpose / Results
4 Conduct
Survey and
Monitoring
Measurements: Motor survey,
Insulation, and Lighting survey with
portable instruments for collection of
more and accurate data. Confirm and
compare operating data with design
data.

Energy Audit
Step
No.
5 Conduct of
detailed trials
/experiments for
selected major
energy equipment
Trials/Experiments:
24 hours power monitoring (MD, PF, kWh etc.).
Load variations trends in pumps, fan
Boiler/Efficiency trials for (4 – 8 hours)
Furnace Efficiency trials
Equipments’ Performance experiments etc.

Energy Audit
Step
No.
6 Analysis of
energy use
Energy and Material balance
Energy loss/waste analysis

Energy Audit
Step
No.
7 Identification and
development of
Energy
Conservation
(ENCON)
opportunities
Conceive, develop, and refine ideas
Review the previous ideas suggested by unit personal
Review the previous ideas suggested by energy audit if
any
Use brainstorming and value analysis techniques
Contact vendors for new/efficient technology

Energy Audit
Step
No.
8 Cost Benefit
Analysis
Assess technical feasibility, economic viability
and prioritization of ENCON options for
implementation
Select the most promising projects
Prioritize by low, medium, long term measures

Energy Audit
Step
No.
Plan of
Action
Purpose / Results
9 Reporting &
Presentation to
the Top
Management
Documentation, Report Presentation to the
top Management
Final Report preparation on feedback from
unit

Energy Audit
Step
No.
Phase III – Post-Audit Phase
10 Implementation
and Follow-up
Assist and Implement ENCON
recommendation measures and Monitor
the performance
Action plan, Schedule for implementation
Monitoring and periodic review

 Initial study of site needed to plan the procedures for audit
 Initial site visit and preparation required for detailed auditing
 Can happen in one day – meet personnel concerned & familiarize the site
to assess procedures necessary for audit
 Actions to be carried out during initial site visit
 Discuss with site’s senior management with the aims of the audit
 Discuss guidelines associated with recommendations of the audit
 Analyse major energy consumption data with relevant personnel
 obtain site drawings –building layout, steam distribution, compressed
air distribution, electricity distribution etc.
 Tour the site accompanied by engineer / production manager
Phase –I: Pre-Audit Phase

Aims of the visit are to:
 Finalize energy audit team
 Identify the main energy consuming areas/plant items to be surveyed during
the audit
 Identify any existing instrumentation/ additional metering required
 Decide whether any meters will have to be installed prior to the audit ex:
kWh, steam, oil or gas meters
 Identify the instrumentation required for carrying out the audit
 Plan with time frame
 Collect macro data on plant energy resources, major energy consuming
centers
 Create awareness through meetings/ program
Phase –I: Pre-Audit Phase

 Depending on nature and complexity of site, comprehensive audit may
take several weeks to months
 Study to establish and investigate, energy & material balance
 Check plant operations over extended periods of time
 Prepare audit report including description of energy inputs and
outputs
 Evaluate efficiency of each step of manufacturing process
 List means of improving efficiencies, indicate cost involved and
payback period
 Include specific recommendations in report for detailed engineering
studies and feasibility analyses, justify the implementation of the
measures that require investments
Phase –II: Audit Phase

Information to be collected includes
 Energy consumption by type of energy, by department, by major process
equipment and by end-use
• Material Balance Data - (raw materials, intermediate and final products,
recycled materials, use of scrap or waste products, production of by-
products for re-use in other industries, etc.)
 Energy cost and tariff data
 Process and material flow diagrams
 Generation and distribution of site services (ex: Compressed air, steam)
 Sources of energy supply (e: electricity from gird or self-generation)
 Potential for fuel substitution, process modifications, and the use of co-
generation systems (combined heat and power generation)
• Energy management procedures and energy awareness training programs
with the establishment
Phase –II: Audit Phase

Instruments used includes
Energy Audit Instruments
 Electrical Measuring
Instruments
 Combustion analyser
 Fuel Efficiency
Monitor
 Fyrite
 Contact thermometer
 Infrared Thermometer
 Pitot Tube and
manometer
 Water flow meter
 Speed Measurements
 Leak Detectors
 Lux meters

Measures:
 kVA, kW, PF, Hertz, kVAr, Amps and Volts
 Harmonics
 Instant measurements at regular intervals
are to be taken
Electrical Measuring Instruments – Power Analyzers

 In-built chemical cells
 Measures gases viz. O2, CO, NOX, SOX
etc.
Combustion Analyzer

 Measures - O2 & Temperature of flue gas
 Combustion Efficiency is calculated by
feeding calorific values of fuels into it
Fuel Efficiency Monitor

 Hand bellow pump draws the flue gas sample
into the solution inside the fyrite.
 Chemical reaction changes the liquid volume
revealing the amount of gas.
 Separate fyrite can be used for O2 and CO2
measurement.
Fyrite

• Thermocouples, which measures for example
flue gas, hot air, and hot water temperatures by
insertion of probe into the stream.
• For surface temperature, a leaf type probe is
used with the same instrument.
Contact Thermometer

 Non-contact type measurement
 When directed at a heat source directly gives
the temperature read out
 Used for measuring hot spots in furnaces,
surface temperatures etc.
Infrared Thermometer

Air velocity in ducts can
be measured using a pitot
tube and inclined
manometer for further
calculation of flows.
Pitot Tube and Manometer

Non-contact flow measuring device using Doppler
effect / Ultra sonic principle
Has a transmitter and receiver, which are
positioned on opposite sides of the pipe
The meter directly gives the flow
Can be used for Water and other fluid flows
Water Flow Meter

 Speed measurements are critical – change with
change in frequency, belt slip & loading
 Tachometers – contact and non-contact type
can be used
 Most efficient – Stroboscopes
Speed Measurements

Ultrasonic instruments are available which
can be used to detect leaks of compressed air
and other gases, which are normally not
possible to detect with human abilities.
Leak Detectors

Measures – Illumination level
Has photocell – senses light output
and converts it into electrical
impulses which are calibrated as lux
Lux Meter

hodeee.asset@ahalia.ac.in
gmurugananth@gmail.com
+91-9942116780 / +91-8248257377

Fundamentals of energy audit

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