What are the procedures involved in Energy Audit?

A). Preparation for energy audit

• Defining the audit criteria
• Defining the audit scope
• Selection of energy audit team
• Making an audit plan
• Preparing an audit checklist
• Conducting the initial walk-through visit
• Collecting energy bills and available data and information
• Conducting the preliminary analysis

B). Analyzing energy bills

• Electricity bills
• Calculating electricity use per day (kWh/day)
• Calculating the Load Factor (LF)
• Natural gas bills
• Coal and fuel oil bills
• Graphical analysis of historical energy use

C). Inventory and measurement of energy use
The most common data measured during the auditing process are:

• Liquid and gas fuel flows
• Electrical measurements, such as the voltage, current intensity and power, as well as power factor
• Temperatures of solid and liquid surfaces
• Pressure of fluids in pipes, furnaces or vessels
• Exhaust gases emissions (CO2, CO, O2 and smoke)
• Relative humidity
• Luminance levels
• Electrical load inventory
• Thermal energy use inventory
• Energy system-specific measurements
• Energy balance

D). Analyzing energy use and production patterns

• Load/Demand profile
• Scatter diagram for presenting the dynamics of the energy-production relationship
• Interpretation of energy-production data pattern on a scatter diagram

E). Benchmarking and comparative energy performance analysis

F). Identifying energy efficiency and energy cost reduction opportunities

• Electrical demand control
• Cross-cutting energy-efficiency improvement options
• Sector-specific energy-efficiency improvement opportunities for selected industrial sectors

G). Cost-benefit analysis of energy-efficiency opportunities

• Life-cycle cost analysis (LCCA)
• Life cycle cost (LCC) method
• Net present value (NPV) method
• Internal rate of return (IRR) method
• Simple payback period (SPP) method

H). Preparing an energy audit report
Some key issues that should be kept in mind while writing an audit report are:

• The audit report should be written in a way that provides suitable information to the potential readers of the report which could be the CEO or plant manager, the supervisor of engineering or maintenance, and the plant shift supervisor.
• The audit report should be concise and precise and use direct language that is easy to understand.
• Use more graphs rather than tables for the presentation of data, results and trends.
• The recommendation section should be specific, clear and with adequate detail.
• Assumptions made in the analysis should be explained clearly. How changes in the key assumptions can influence the results should also be explained. A sensitivity analysis is a very helpful tool for this.
• The auditors should do their best to avoid mistakes and errors in the report especially in the results. Even a few errors could damage the credibility of the audit.
• The energy audit report should be consistent in structure and terminology used.
• The calculations made in the analysis work should be explained clearly.

I). Post-audit activities

• Create an action plan for the implementation of energy-efficiency measures
• Implement the action plan
• Evaluate Progress