Energy audit means 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

• It is a crucial step because it provides a means for identifying the most energy consuming areas and solution to reduce the energy consumption thereby increasing energy efficiency.
• With energy auditing one can easily reduce energy bill between 5 % to 25 %.
• Energy Auditing is done by accredited energy auditor which means an auditor possessing qualifications.

Objectives of Energy Audit

The Energy Audit provides the vital information for overall energy conservation program covering essentially energy utilization analysis and evaluation of energy conservation measures. It aims at:

• Identifying the quality and cost of various energy inputs.
• Assessing present pattern of energy consumption in different cost centers of operations.
• Relating energy inputs and production output.
• Identifying potential areas of thermal and electrical energy economy.
• Highlighting wastage's in major areas.
• Fixing of energy saving potential targets for individual cost centers.

Type of Energy Audit

The type of Energy Audit to be performed depends on:

• Function and type of industry
• Depth to which final audit is needed, and
• Potential and magnitude of cost reduction desired

Thus Energy Audit can be classified into the following two types.

1. Preliminary Audit
2. Detailed Audit

Preliminary Energy Audit Methodology

Preliminary energy audit is a relatively quick 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
• Preliminary energy audit uses existing, or easily obtained data

Detailed Energy Audit Methodology

A comprehensive audit provides a detailed energy project implementation plan for a facility, since it evaluates all major energy using systems. This type of audit offers the most accurate estimate of energy savings and cost. It considers the interactive effects of all projects, accounts for the energy use of all major equipment, and includes detailed energy cost saving calculations and project cost.

In a comprehensive audit, one of the key elements is the energy balance. This is based on a inventory of energy using systems, assumptions of current operating conditions and calculations of energy use. This estimated use is then compared to utility bill charges.

Detailed energy auditing is carried out in three phases: Phase I, II and III.
Phase I - Pre Audit Phase
Phase II - Audit Phase
Phase III - Post Audit Phase