Energy Audit – VIT University Vellore
1. INTRODUCTION AND DEFINITON
An energy audit is a preliminary activity towards instituting energy efficiency programs in an establishment. It consists of activities that seek to identify conservation opportunities preliminary to the development of an energy savings program. The energy audit in a building is a feasibility study. For it not only serves to identify energy use among the various services and to identify opportunities for energy conservation.
2. BACKGROUND AND OBJECTIVE
The Energy Audit would give a positive orientation to the energy cost reduction, preventive maintenance and quality control programmes which are vital for production and utility activities. Such an audit programme will help to keep focus on variations which occur in the energy costs, availability and reliability of supply of energy, decide on appropriate energy mix, identify energy conservation technologies, retrofit for energy conservation equipment etc. In general, Energy Audit is the translation of conservation ideas into realities, by lending technically feasible solutions with economic and other organizational considerations within a specified time frame.
The primary objective of Energy Audit is to determine ways to reduce energy consumption
per unit of product output or to lower operating costs. Energy Audit provides a " bench-mark"
(Reference point) for managing energy in the organization and also provides the basis for planning a more effective use of energy throughout the organization.
Energy Audit can be classified into the following two types.
i) Preliminary Audit
ii) Detailed Audit
• Preliminary Energy Audit Methodology
• 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.
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
Existing baseline information and reports are useful to get consumption pattern, production cost and productivity levels in terms of product per raw material inputs. The audit team will collect the following baseline data:
- Technology, processes used and equipment details
- Capacity utilisation
- Amount & type of input materials used
- Water consumption
- Fuel Consumption
- Electrical energy consumption
- Other inputs such as compressed air, cooling water etc
- Quantity & type of wastes generated
- Percentage rejection / reprocessing
- Efficiencies / yield
The information to be collected during the detailed audit includes: -
1. Energy consumption by type of energy, by department, by 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 re-use in other industries, etc.)
3. Energy cost and tariff data
4. Process and material flow diagrams
5. Generation and distribution of site services (eg.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.
The objective of energy audit is to identify the end use of energy in building and its ECOs; and as a feasibility study leading to implementation of an energy management programme. The audit procedures can be expanded as needed in the various phases of the energy programme, with the application of each succeeding phase yielding more information on energy use, and more opportunities for raising energy efficiency.