What is an Energy Audit? Definition, Method and Action Plans

Problem Statement

Not many is aware that a lot of 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 does not perform regular check up on energy usage and/or take any measurement on energy optimization, aging plants has a tendency to be overusing energy. Considering the energy capacity of an operating plant, an overusing of energy contribute to a scarcity in this energy supply and thus an increase in overall electricity costs.

Introduction 

An energy audit is introduced for plants to ensure energy efficient. 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 – that contains recommendations and action plan for energy optimization together with a cost benefit analysis. Prior tho the conduct of energy audit, scope of energy audit and level of economic evaluation should be pre-defined.

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

Methodology 

Energy Audit is conducted to determine ways intended 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 are properly planned during audit activities. Details of facilities are identified thoroughly to be included in the scope of audit process. Kick off meeting are carried out to discuss on any firsthand observation and assessment on prevailing level operation and pre-defined practices on certain facilities.

  1. Audit Phase

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

(i) Gather 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 questionnaire/ survey may be conducted by auditor to operation team. This enables auditor to grasp a better understanding on performance of facility.

(ii) Conduct Site Survey, Monitoring and Measuring

A site survey will be conducted to identify source of supply to the facilities. Supply facility such as the loads (i.e motors, lighting, compressor) as well as its condition.  A measurement of power consumption (i.e Nominal Current) ofthe 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 Measure (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 measurement will be taken place 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 plan that can be implemented to achieve energy efficient:

Action Item to Energy Efficient
Figure 3: Sample of Action Item to Energy Efficient