Get an expert energy audit
If you spend more than $150,000 per year on energy, consider having a third party conduct an energy audit. A successful energy audit shows how efficiently your business uses its energy.
- What audits aim to do
- Who should do audits
- Areas to audit
- Different types of audit
- How audits progress
- Staff involvement
- Maintaining the information
An audit should improve your profitability. You may also want an energy audit because of immediate energy shortages, environmental concerns or to improve your energy or environmental rating. Your audit should show energy use as costs and recommend the most cost-effective options, rather than options that use less energy overall.
We recommend you use an Energy Management Association of New Zealand (EMANZ) accredited auditor, who’ll have technical ability, experience and bring an independent perspective. Although in-house audits may keep costs down, a comprehensive energy audit (in accordance with AS/NZS 3598:2015) takes time - in our experience, in- house staff faced with competing priorities rarely manage to finish them.
You can find an energy auditor on the Energy Management Association of New Zealand (EMANZ) website.
For large or multiple sites, it can be a good idea to do a pilot survey to find key areas for the full audit. You can also review your historical energy usage to find out where your business uses the most energy.
The New Zealand and Australia Energy Auditing Standard AS/NZS 3598/2000 specifies what should be done in an audit. The standard lists 3 levels of energy audit:
- Type 1: Basic energy audit - provides a quantitative overview of energy performance and identifies low cost opportunities with payback of up to 2 years. Type 1 audits are suitable for smaller energy users of as a scoping energy audit of a large energy using site or process.
- Type 2: Detailed energy audit - provides detailed analysis of energy performance to quantify the full range of opportunities for a site. Type 2 audits involve a comprehensive review and analysis of equipment systems, and operational characteristics of the whole facility to enable quantified implementable energy savings recommendations.
- Type 3: Precision subsystem audit - Type 3 audits are detailed audits of specific subsystems, with additional data gathering and measurement to provide a higher level of accuracy than is possible with Type 2. Type 3 audits are normally undertaken to support business cases for capital intensive upgrades that require more certainty around savings outcomes.
Type 3 audits include the audits of the following systems:
- compressed air
- process heat (boilers, steam and hot water systems)
The most valuable part of the audit report is often the list of energy savings opportunities that will enable you to prepare your action plan. For a copy of a model audit visit the Resources section of the Energy Management Association of New Zealand (EMANZ) website.
1. Determining the brief for an auditor
Consider all uses of energy in your building, including process energy, refrigeration, lighting, motor systems, heating, ventilating, air conditioning (HVAC systems) and domestic hot water. You can also restrict the brief to specific systems or features, or widen it to include associated areas such as water consumption.
2. Analysing historical energy usage
This should compare your current energy use with other months or years, analysing usage patterns for unusual highs and lows, and seasonal variations. The analysis can identify anomalies such as heating systems that operate into the summer, and discrepancies between billings and usage patterns.
3. Technical analysis
This is usually the heart of an audit. Significant energy loads should be analysed by a person knowledgeable of those systems. Each major energy-using system should have its own section in the audit report. Auditors need to understand your process and you need to specify what the audit should cover.
A useful audit report will have clear and brief discussions, clear tables or graphs, concise explanations and prioritised costs and payback periods. Calculating a simple payback period is a useful tool for prioritising, but may under-sell long term projects. Make sure these benefits are accounted for by specifying the type of long term analysis your organisation usually uses.
The closer you and your staff work with your auditor, the more valuable your audit report will be. The audit’s effectiveness can be compromised if auditors don’t access your staff’s wealth of understanding about their plant, processes or buildings.
Audits have use-by dates because operations and working environment in any organisation constantly evolve.