Guide for Conducting Energy Audit

• Conduct of brief meeting/awareness programme with all divisional heads and persons concerned (2-3hrs).

Purpose/Results :

• Resource planning, Establish/organize a Energy audit team.
• Organize Instruments and time frame.
• Macro Data collection (suitable to type of industry).
• Familiarization of process/plant activities.
• First hand observation and Assessment of current level operation and practices.

Step 2 :

• Building up co-operation.
• Issue questionnaire for each department.
• Orientation, awareness creation.

Phase II – Audit Phase :

Plan of Action :

Step 3 :

• Primary data gathering, Process Flow Diagram, & Energy Utility Diagram.

Step 4 :

• Conduct survey and monitoring.

Step 5 :

• Conduct of detailed trials/experiments for selected energy guzzlers.

Step 6 :

• Analysis of energy use

Step 7 :

• Identification and development of Energy Conservation (ENCON) opportunities.

Step 8 :

• Cost benefit analysis.
• Reporting and Presentation to the Top Management.

Purpose/Results :

Step 3 :

• Historic data analysis . Baseline data collection.
• Prepare process flow charts.
• All service utilities system diagram (Example : Single line power distribution diagram, water, compressed and steam distribution.
• Design operating data and schedule of operation Annual energy bill and energy consumption pattern (Refer manual log sheet name plate, interview).

Step 4 :

• Measurements : Motor survey, insulation, and lighting survey with portable instruments for collection more and accurate data. Confirm and compare operating data with design data.

Step 5 :

Trials/Experiments
– 24 hours power monitoring (MD, p.f., kWh etc).

– Load Variations/trends in pumps, fan, compressors etc.

– Boiler/Efficiency/trials for 4 – 8 hours.

– Furnace efficiency trials equipments performance experiments etc.

Step 6 :

• Energy and Material balance and energy loss/waste analysis.

Step 7 :

• Identification and consolidation ENCON measures.
• 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.

Step 8 :

• Assess technical feasibility, economic viability and prioritization of ENCON options for implementation.
• Select the most promising projects.
• Prioritise by low, medium, long term measures.

Step 9 :

• Documentation, report presentation to the top management.

Phase Post Audit Phase :

Plan of Action :

Implementation and follow-up.

Purpose / Results :

Step 10 : 

Assist and implement ENCON recommendation measures and monitor the performance

• Action plan Schedule for implementation
• Follow-up and periodic review.

Phase I- Pre-Audit Phase Activities :

• A structured methodology to carry out an energy audit is necessary for efficient working
• An initial study of the site should always be carried out as the planning of the procedures necessary for an audit is most important.

Initial Site Visit and Preparation Required for Detailed Auditing : 

An initial site visit may take one day and gives the Energy Auditor/Engineer an opportunity to meet the Personnel concerned, to familiarize him with the site and to assess the procedures necessary to carry out the energy audit.
During the initial site visit the Energy Auditor/Engineer should carry out the following  activities :

1. Discuss with the site’s senior management the aims of the energy audit.
2. Discuss economic guidelines associated with the recommendations of the audit.
3. Analyse the major energy consumption data with the relevant personnel.
4. Obtain site drawings where available-building layout steam distribution compressed air distribution electricity distribution etc.
5. Tour the site accompanied by engineering/production. 

The main aims of initial site visit are :

1. To finalise Energy Audit team.
2. To identify the main energy consuming areas / plant items to be surveyed during the audit.
3. To identify any existing instrumentation / additional metering required.
4. To decide whether any meters will have to be installed prior to the audit eg kWh, steam oil or gas meters.
5. To identify the instrumentation required for carrying out the audit.
6. To plan with time frame.
7. To collect macro data on plant energy resources, major energy consuming centers.
8. To create awareness through meetings/programme.

Phase II -Detailed Energy Audit Activities :

• Depending on the nature and complexity of the site, a comprehensive audit can take from several weeks to several months to complete.
• Detailed studies to establish and investigate, energy and material balances for specific plant departments of items of process equipment are carried out.
• Whenever possible checks of plant operations are carried out over extended periods of time, at nights and at weekends as well as during normal daytime working hours, to ensure that nothing is overlooked.
• The audit report will include a description of energy inputs and product outputs by major major processing function and will evaluate the efficiency of each step of the manufacturing process. 
• Means of improving these efficiencies will be listed and at least a preliminary assessment of the cost of the improvements will be made to indicate the expected payback on any capital investment needed.
• The audit report should conclude with specific recommendations for detailed engineering studies and feasible , analyses which must then be performed to justify the implementation of those conservation measures that require investments.

 The information to be collected during detailed audit is as follows : 

1. Energy consumption by type of energy, department major items of process equipment, by end- use. 
2. Material balance data (raw materials, intermediate and final products, recycled materials, use of scrap or waste products, production of by-products for reuse in other industries, etc). 
3. Energy cost and tariff data.
4. Process and material flow diagrams. 
5. Generation and distribution of site services (e.g compressed air, steam). 
6. Sources of energy supply (e.g. electricity from the grid or self-generation ). 
7. Potential for fuel substitution process modifications, and the use of co-generation systems (combined heat and power generation).
8. Energy Management procedures and energy awareness training programs within the establishment. 

• Existing baseline information and reports are useful to get consumption pattern productivity levels in terms of product per raw material inputs.
• The audit team should collect the following baseline data :

1.Technology, processes used and equipment details.

2.Capacity utilization.

3.Amount and type of input materials used.

4.Water consumption.

5.Fuel consumption.

6.Electrical energy consumption.

7.Steam consumption.

8.Other inputs such as compressed air cooling water etc.

9.Quantity and type of wastes generated.

10.Percentage rejection/reprocessing.

11.Efficiencies/yield.

Data collection hints to avoid wasting efforts and time :

1. Design values can be taken where measurements are difficult (cooling water through heat exchanger).
2. Measurement exercises over abnormal workload periods (such as startup and shutdowns).
3. The quality of the data must be such that the correct conclusions are drawn (what grade of product is on the production normal etc).
4. Measurement equipment can be inexpensive (flow rates using a bucket and stopwatch).
5. Measurement systems should be easy to use and provide the information to the accuracy that is needed, not the accuracy that is technically possible.
6. Define how frequent data collection should be to account for process variations.

Draw process flow diagram and list process steps ; identify waste streams and obvious energy wastage : An outline of unit operations, important process steps, areas of material and energy use and sources of waste generation should be gathered and should be represented in a flowchart as shown in Figure A. Existing drawings, records and shop floor walk through will help in making this flow chart. Simultaneously the team should identify the various inputs and output streams at each process step. 

Example : A flowchart of Penicillin – G manufacturing is given in the Figure. Note that waste stream (Mycelium) and obvious energy wastes such as condensate drained and steam leakages have been identified. The audit focus area depends on several issues like consumption of input resources, energy efficiency potential, impact of process step on entire process or intensity of waste generation / energy consumption. In the above process, the unit operations such as germinator, pre-fermentor, fermentor, and extraction are the major conservation potential areas identified.