Energy conservation and energy efficiency are attractive solutions for reducing operating costs and the environmental impacts associated with the use of conventional energy resources. Good energy management starts with an energy audit.
Viet Nam’s Law on Energy Efficiency and Conservation describes an energy audit as the measurement, analysis, calculation, and assessment of energy to determine consumption level and energy saving potential, and offers solutions for economical and efficient use of energy. It is also a systematic analysis of energy consumption by audited objects to identify, quantify, and report on opportunities for improved energy performance according to ISO 50002 – Energy audits.
2. How does it work?
According to Circular 09/2012/TT-BCT on planning, reporting plans for energy saving and efficiency, and performing energy audits, there are six steps in the general procedure that can be outlined for most facilities.
Step 1 Identify the scope of the energy audit
The main purpose of this step is to identify the scope and resources available for the energy audit. Determine of which areas and/or equipment need to be audited. Resources should include human and monetary.
Step 2 Establishment of an energy audit team
An energy audit team comprising competent and certified energy auditors should be set up.
Step 3 Estimating time period and cost
The energy audit team has the responsibility to estimate the time and cost required. The energy audit cost comprises labor cost (estimated based on the number of hours the auditors work) for possibly hiring outside experts and the use of measuring devices.
Step 4 Collecting available data
In this step, a list of available data is collected, which includes:
a) Technical characteristics of relevent equipment and production lines (such as: gross floor area, structure, orientation, type and quantity of equipment should be noted).
b) Process of operation equipment and equipment troubleshooting guides.
c) Reports of operation, status of equipment repair and recording of measured data such as temperature, pressure, operating hours etc.
d) What energy efficient solutions were adopted and planned
e) Energy bills for the last three years
f) Record of energy consumption and maximum energy use if available
Auditors have to compare operation specifications of existing equipment with their designed requirements throughout collected data. This helps to detect areas that are wasting energy significantly.
Step 5 Measurement
If there is a lack of sufficient data, the energy audit team has to take its own measurements. Auditors should determine which areas and devices are going to be measured. Templates should then be created for measurement records before performing the planned audit.
Step 6 Analysing collected data
The result of this step is to find out energy saving potential through analysing the data collected. The effectiveness of solutions should be demonstrated by using net present value (NPV) and/or the internal rate of return (IRR) method as well payback time.
ISO 50002 is also used as a basis for an energy audit (see flow chart below).
Process of an energy audit according to ISO 50001(1)
– Identifying potential energy-saving solutions and the priority level for each solution.
– Assessing the impact of energy-saving solutions on business operations.
– Increasing awareness of energy use among employees and managers at facilities.
According to Circular 09/2012/TT-BCT, there are two kinds of energy audits: walk-through and detailed. The table below shows the differences between the two.
To be able to perform an energy audit, an auditor must take a test and obtain an energy auditor’s certificate.
Energy audit training is provided by organisations that meet the requirements of Cricular 39/2011/TT-BCT — such as the Energy Conservation Center in cities and provinces around Viet Nam etc.
(1) ISO 50002 – Energy audits, the International Organization for Standardization, 2013
(2) The 09/2012/TT-BCT Circular requires the planning, reporting plans to use energy saving and efficiency and performing energy audits, Ministry of Industry and Trade, 2012
(3) Law on Energy efficiency and Conservation in Viet Nam, National Assembly, 2010
(4)The 39/2011/TT-BCT Cricular requires training, providing certification of energy management and energy auditors.