In broad terms an energy audit (or water audit) involves collecting and analysing billing data for all energy sources and determining total energy usage, a site analysis to identify where energy is used and energy savings opportunities, doing calculations to estimate the cost/benefit of the energy savings opportunities, and producing and presenting a report which recommends what can be done to save energy.
The two key outputs of an energy/water audit are an assessment of how much energy is used and where its used at an individual facility, and, secondly and most importantly an identification of energy savings opportunities, quantified with estimates of the investment required, and annual savings expected, for each opportunity.
An energy audit is typically undertaken by an energy auditor – usually an engineer -and will involve a site assessment, analysis and report. Typically audits are undertaken to a standard, in Australia either AS/NZS 3598.1 (2014) Commercial Energy Audits or AS/NZS 3598.2 (2014) Industrial Energy Audits is used.
Advantages of an energy audit
An energy audit will give you a list of action items, with estimated costs and benefits, to reduce your energy usage, energy costs and carbon footprint. With this clear guidance, its easy to prioritise and know exactly what you need to do to reduce your energy costs and greenhouse gas emissions, how much you’ll need to spend, and what you can expect to save.
When undertaken by an experienced energy auditor:
- An auditor should be able to identify a greater number of savings opportunities than you could on your own.
- An auditor will be able to come up an estimate of savings to an acceptable degree of accuracy (as determined by the audit scope).
- An auditor can identify likely desired and undesired consequences of a particular upgrade, and undertake calculations to quantify them. Eg. In a cold climate the auditor would quantify both the electricity savings arising from upgrading office lighting to high efficiency LED, and the increased energy usage of the heating system to heat the buildings (as more efficient lights produce less heat, heat which usually helps keep the office warm). The maintenance savings from longer lasting LEDs would also be identified.
- An auditor can give you up to date advice on specific technologies.
- An auditor can help you avoid investments in well-marketed technologies with dubious energy saving potential.
Disadvantages of an energy audits
The key disadvantage of an energy audit is that it doesn’t save any energy. It won’t reduce your carbon footprint. Your energy bills won’t come down.
It will tell you how to save energy, but action on the report’s recommendations needs to be taken to save energy.
Some other disadvantages are:
- The audit has a “use by date” or limited useful life. As technologies change, energy tariffs change, use of a facility changes, over time the recommendations and numbers in an energy audit will become out of date. For this reason, energy audit standards generally consider that energy audits should be repeated every 3 years.
- An energy audit isn’t a design or works specification. You’ll still need to invest in a design and specification to get a project “shovel ready”.
- An energy audit could be poorly done. Especially if you haven’t provided a clear scope of works to the auditor and been careful in auditor selection.
- The results of an audit cannot be predicted beforehand. You don’t know whether or not you can cut your electricity usage by 25% with less than a one year payback (not usual, but I’ve certainly seen this result), or by just 10% with a 6 year payback (at the other extreme, also rare, but I’ve also seen this result too).
Interested in learning more, or keen to reduce your energy use and greenhouse gas emissions? Get in touch: