In any industry, the three top operating expenses are often found to be energy (both electrical and thermal), labor, and materials. In most assessments of the manageability of the cost or potential cost savings in each of the above components, energy would invariably emerge as a top ranker, and thus energy management function constitutes a strategic area for cost reduction. A well done energy audit will always help managers understand more about the ways energy and fuel are used in their industry, and help to identify areas where waste can occur and where scope for improvement exists.
The energy audit would give a positive orientation to the energy cost reduction, preventive maintenance, and quality control programs which are vital for production and utility activities. Such an audit program will help to keep focus on variations that occur in the energy costs, availability, and reliability of supply of energy, help decide on the appropriate energy mix, identify energy conservation technologies, retrofit for energy conservation equipment, etc.
The primary objective of the energy audit is to determine ways to reduce energy consumption per unit of product output or to lower operating costs. The energy audit provides a benchmark, or reference point, for the management and assessment of the energy use across the organization and provides the basis for ensuring more effective use of energy.
The type of energy audit to be performed depends on:
Thus energy audits can be classified into the following two types:
The preliminary energy audit uses existing or easily obtained data. It is a relatively quick exercise to:
A PEA is essentially a data gathering exercise which aims to develop in understanding of how energy is used in a factory, and prepare a background for detailed energy audit (DEA) implementation.
A Detailed Energy Audit provides a comprehensive 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.
The general flowchart of an Industrial Energy Audit can be seen here below: