1. SALIENT ASPECTS OF ENERGY AUDIT
SANJAY GHOSHAL
BE (Gold Medalist), MBA CEA ,PROFESSIONAL ENGINEER
K.RAMESH
BE, CEACEM,FIE,FMSESI,CHARTERED ENGINEER (India)

2. What is Energy Audit ??? AN ENERGY AUDIT IS A PRELIMINARY ACTIVITY
TOWARDS INSTITUTING ENERGY EFFICIENCY
PROGRAMS IN AN ESTABLISHMENT.
IT CONSISTS OF ACTIVITIES THAT SEEK TO IDENTIFY ENERGY CONSERVATION OPPORTUNITIES PRELIMINARY TO THE DEVELOPMENT OF AN ENERGY SAVINGS PROGRAM.

3. NEED FOR ENERGY AUDIT AN ENERGY AUDIT WILL:
HELP TO UNDERSTAND HOW ENERGY AND FUEL ARE USED IN INDUSTRY
IDETIFY AREAS WHERE WASTE OCCURS AND WHERE THERE IS SCOPE FOR IMPROVEMENT
GIVE A POSITIVE ORIENTATION TO ENERGY COST REDUCTION
TRANSLATE CONSRVATION IDEAS INTO REALITY

4. Energy Audit Definition
As per Energy Conservation Act 2001, Energy Audit is defined as:
“ The Verification, Monitoring & 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”.

5. Types of Energy Audit Preliminary energy audit Detailed energy audit
Type of Energy Audit
The type of Energy Audit to be performed depends on.
-         the function and type of industry
-         the depth to which final audit is needed, and
-         the potential and magnitude of cost reduction desired
Thus Energy Audit can be classified into the following two types.
i)        Preliminary Audit
ii)       Detailed Audit

6. Preliminary Energy Audit
Also called simple audit or walk through audit
It involves:
i) minimal interview with site personnel
ii) brief review of operating data
iii) walk through of plant to ---
Identify glaring areas of wastage & inefficiency
Estimate the scope for saving
Identify the most likely areas for attention
Identify immediate ( no-/low-cost) improvements
Set a ‘reference point’
Identify areas for more detailed study/measurement
2.      Collect the existing data e.g., a energy bills(volume/cost)
     Collect the Production output/records plant layouts using checklists
3. Analyse data:
     Find unit cost of energy (Rs./ kWh for all types)
     Find fixed and variable energy element
     Derive ‘energy Index’: energy cost/unit output ,energy cost/floor area
4.      Formulate plan:
Formulate Immediate energy-saving actions: Where? How ? How much?
         Areas to investigate further
         Resources required for more detailed study
5.      Actions and monitoring
Next steps (e.g. detailed audits), where needed

7. Detailed Energy Audit
This Expands on the Preliminary Energy Audit by :-
Collecting more detailed information of plant operations
Identifying all energy conservation measures appropriate for the unit
Performing more detailed evaluation of energy conservation measures identified
Performing detailed financial analysis of each measure to justify implementation.

8. Energy Audit Methodology
Comprehensive TEN Step Methodology involves:
Interview with key Plant Personnel with focus on:-
i) Audit objectives & scope of work
ii) Plant rules and regulations
iii) Roles and responsibilities of Audit Team Members
iv) Description of scheduled project
activities

9. Plant Tour:-
After the initial meeting, a tour of the Plant is undertaken to:-
i) Observe the various operations first hand
ii) Focus on major Energy consuming
systems identified during the interview
including Lighting & Power, Mechanical
and Process energy systems.
Documentation Review:-
Review plant documentation including –
i) All available engineering plans
ii) All service Utilities system diagram
iii) Plant operation & maintenance
procedures and logs
iv) Annual Energy bills and consumption pattern

10. Plant Inspection :-
i) For further investigation of major energy
consuming processes
ii) Taking field measurements to
substantiate operating parameters
iii) Conducting detailed trials and surveys
such as Motor survey, insulation and
lighting survey etc.
Staff Interview:-
Meet again with the department staff to –
i) review the preliminary findings and
recommendations being considered
ii) Management input at this stage will help
to establish the priorities that form the
foundation of the Energy Audit

11. Plant Analysis
Carry out an analysis of energy usage in the plant through:-
i) Detailed review of “energy bills” of
all purchased energy for the
previous 12 to 36 months
ii) Energy and material balance &
energy loss/waste analysis
This data is also used as a baseline to compute projected energy savings for the
‘Energy Conservation Measures’ (ECM)

12. Identify and Evaluate Suitable ECM’s
An energy audit will uncover:-
i) Major plant modifications requiring
economic analysis
ii) Minor operation modifications offering
simple/quick pay backs
A list of Major ECM’s is developed for each of the energy consuming systems (process, power, lighting)
Based upon a final review and reaction of Plant personnel, a finalized list of ECM’s is developed and reviewed with the Plant Manager

13. Economic Analysis
The data collected during the Audit is :-
i) Processed and analyzed for technical and
economic viability
ii) Models are built and simulations done to
reproduce field observations
iii) Baseline is developed, against which to
measure the energy savings potential of
the identified ECM’s
The implementation cost, energy savings and simple pay back period for each of the investigated ECM’s is calculated
iv) Select the most promising projects and
prioritise the ECM’s

14. Preparation of Final report
The results are summarized in a Final Report
This report includes:-
i) Description of Plant and Operations
ii) Discussion of all major energy consuming
systems
iii) Description of all recommended ECM’s with
their specific energy impact
iv) Implementation Costs
v) Benefits & Pay back

15. Presentation to Top Management,
Implementation and Follow Up
The Final Recommendations are presented to the Top Management, to make a decision on which ECM’s are to be implemented
Assist in implementation of Recommended ECM’s and monitoring of Performance
Follow Up and periodically review the progress

16. Identification of Energy Conservation Opportunities
Energy generation
 Energy distribution:
Energy usage by processes:
Fuel substitution:

17. Benchmarking for energy performance
Internal Benchmarking
Historical and trend analysis
External Benchmarking
Across similar industries
Scale of operation, vintage of technology, raw material specification and quality and product specification and quality

18. Benchmarking parameters
Gross production related
e.g. kWh/MT clinker or cement produced (cement plant)
e.g. kWh/MT, kCal/kg, paper produced (Paper plant)
e.g. kCal/kWh Power produced (Heat rate of a power plant)
e.g. Million kilocals/MT Urea or Ammonia (Fertilizer plant)
Equipment / utility related
e.g. kWh/ton of refrigeration (on Air conditioning plant)
e.g. % thermal efficiency of a boiler plant
e.g. kWh/NM3 of compressed air generated
e.g. kWh /litre in a diesel power generation plant. 

19. Optimizing Input Energy Requirement
Shuffling of compressors to match needs.
Periodic review of insulation thickness
Identify potential for heat exchanger networking and process integration.
Optimization of transformer operation with respect to load

20. Fuel and Energy Substitution
Fuel substitution
Natural gas is increasingly the fuel of choice as fuel and feedstock in the fertilizer, petrochemicals, power and sponge iron industries.
Replacement of coal by coconut shells, rice husk,etc
Replacement of LDO by LSHS
Energy substitution
Replacement of electric heaters by steam heaters
Replacement of steam based hot water by solar systems

21. Energy Audit Instruments

22. Energy Audit Instruments

23. Energy Audit Instruments

24. THANKS