Microsoft Word 2012, Källén, M.,-Energy Efficiency Opportunities within the Heat Treatment Industry

2.3  Energy Audit 

A complete energy audit should consist of five parts according to the Swedish Energy 

Agency: 

•  A description of the plant. 

•  Mapping of the current energy consumption in the plant. 

•  The short-term energy consumption in the plant. 

•  The long-term energy consumption in the plant. 

•  A search for energy efficiency improvement possibilities. 

The description of the plant works as a definition of the system boundaries for the energy 

audit. A suitable way to describe the plant is to draw block diagram over the process. A plant 

usually refers to a geographically connected facility. The block diagram can be an important 

tool in the entire energy audit. [9] 

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The mapping of the current energy consumption in the plant is the foundation for the 

following analysis. It should give an overview of the systems and equipment which affect the 

energy consumption. Already existing data need to be complemented with measurements, 

assumptions and calculations to get a comprehensive overview. The results may be presented 

in form of energy balances for the plant. External factors which have influenced the energy 

consumption, as well as recurring variations in the energy consumption, should also be 

accounted for. [9] 

The assessment of the short-term energy consumption is based on already planned and 

expected changes in the plant. The long-term energy consumption assessment can be used for 

the short-term energy consumption planning. The long-term energy consumption assessment 

should investigate future production conditions, if these are likely to differ from the present. 

The main purpose of an energy audit is usually to identify energy efficiency improvement 

possibilities. The improvement possibilities should be evaluated based on their technical and 

economic potential. [9]