Energy Audit- Definition, Method and Action Plans

Problem Statement

There are many plants and facilities in Malaysia have been in operation for a long period of time. For instance, Sultan Salahuddin Abdul Aziz Power Station in Selangor was opened in March 1987, and it is still actively in operation. If operators do not perform regular check ups on energy usage or take any energy optimization measures, aging plants have a tendency to be overusing energy. This contributes to a scarcity in this energy supply and thus an increase in overall electricity and utility costs.


An Energy audit is introduced for plants to ensure energy efficiency. An energy audit can be defined as a process of verification, monitoring, and analysis the use of energy – which can be a part of the Technical Report, which contains recommendations and action plan for energy optimization together with a cost benefit analysis. Prior to conducting an energy audit, the scope and level of economic evaluation should be pre-defined.

Reason to perform an Energy Audit
Figure 1: Reason to perform an Energy Audit


Energy Audit is conducted to determine ways to reduce energy consumption per unit of product output and/or to lower operating costs for facilities. The audit consists of three(3) phases which namely the Pre Audit Phase, Audit Phase and Post Audit Phase.

  1. Pre Audit Phase

Pre Audit Phase focuses on the planning for audit process. An energy audit team is established at this stage to ensure coordination during audit activities. Details of facilities are identified thoroughly to be included in the scope of audit process. A Kick off meeting is carried out to discuss on any firsthand observation and assessment on prevailing operation levels and pre-defined practices on certain facilities.

  1. Audit Phase

There are a few steps in Audit Phase specified in the following:

(i) Gathering Primary Data

Data collection of energy usage on facilities will be gathered. Data may include facilities drawings, electricity supply, metering, energy consumption and production details. Some qualitative method such as questionnaires/ surveys may be conducted by the auditor to the operation team. This enables the auditor to grasp a better understanding on the facilities performance.

(ii) Conduct Site Survey, Monitoring and Measuring

A site survey will be conducted to identify the source of supply to the facilities. Supply facilities includes the loads (i.e motors, lighting, compressor etc.) as well as its condition.  A measurement of power consumption (i.e Nominal Current) of the loads will be collated for analysis purposes.

(iii) Analysis of Energy Use

The result of site survey together with the collection of primary data will be utilized as a basis of analysis for energy consumption. This stage is intended to identify areas of concern. Some example analysis result can be presented in an energy analysis or energy waste/loss analysis.

(iv) Reporting and Presentation

The energy audit report will be presented in the following structure:

  • Summary
  • Description of Facility
  • Historical Data of Energy Use of Facility
  • Current Energy Use
  • Energy Saving Measures (Including implementation of cost and estimated saving)
  • Strategy for Implementation (Recommended energy saving plan/ action plan)
  • Expectation (achieved saving after implementation of the action plan together with calculated profitability)
  1. Post Audit Phase

Monitoring actions and measurements will take place to ensure action plan is fulfilled. Schedule for implementation will be recorded and reviewed periodically.

Three Phase of Energy Audit
Figure 2: Summary of of Energy Audit phases

Action Plan  

There are several action plans that can be implemented to achieve energy efficiency:

Action Item to Energy Efficient
Figure 3: Sample of Action Items to achieve Energy Efficiency