Squeeze more out of your data
- Do statistical analysis of your data, such as regression analysis and CUSUM (cumulative sum difference) analysis. These are available on spreadsheet programmes.
- Set up an energy use index (EUI), which is total energy use divided by floor area of a building, or divided by production. Plotting this and other variables on graphs is the clearest way to share the information with your staff.
- Factor out changes beyond your control, such as weather conditions or operational changes caused by seasonal demands.
- seasonal output variation by dividing energy by actual output
- production demand changes by dividing energy by actual output
- space heating and cooling loads by dividing energy by weather data.
You can also gather richer data by setting up more data collection points, with sub metering for every energy accountable centre (EAC). This means you can focus on equipment or processes that use large amounts of energy.
Base your decision to invest in an M&T programme on the potential results. You can expect to make savings of between 5% and 25% of your annual energy expenditure. With a reasonable midway point of 15% savings in mind, a rule of thumb is to budget about 2.5% of your annual energy expenditure for setting up and operating an M&T programme. Generally, you can expect to recoup set-up costs in the first year.
The core elements of an M&T programme are:
- Recording data - your data will be gathered in three main categories: energy consumption figures, energy costs and information about energy drivers such as floor area, production runs and temperature variations.
- Analysing data - correlating energy consumption with key outputs, such as production quantity or ambient temperatures.
- Setting targets and benchmarking - approaches include historically-based incremental improvements, industry benchmarks or arbitrary goals.
- Monitoring - comparing energy consumption to a set target on a regular basis.
- Reporting – typically regular, weekly or monthly. Exception reports are produced when something unexpected happens. On-demand reports are initiated by request or as the result of an investigation.
- Controlling - when you identify low-performing sites or cost centres, billing discrepancies or unexpected usage variations, find the cause and act on it.
M&T is usually overseen by an energy manager. Collaboration with an external consultant or an M&T software provider can help your business extract more value out of the programme.
Bring in an expert energy auditor
If you spend more than $150,000 per year on energy, an energy audit by an external expert is extremely worthwhile.
A comprehensive audit (in accordance with AS/NZS 3598:2015) takes time – usually more than in-house staff have available.
There are 3 types of 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 2: Detailed energy audit - provides detailed analysis of energy performance to quantify the full range of opportunities for a site.
- Type 3: precision subsystem audit - detailed audits of specific subsystems, with additional data gathering and measurement for a higher level of accuracy.
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.
Set your savings targets
Targets are the measurable numbers behind the goals in your strategy and action plan. Make them challenging but attainable within your resources. Choose whatever units are relevant to you, such as kilowatt hours per month (kWh/month) or kilowatts per kilo of output.
These are effective ways to set good targets:
- Internal benchmarks – compare a site’s overall energy consumption or process with similar sites or processes in your business.
- External benchmarks – compare your organisation’s performance with an industry standard. Contact your sector’s industry association or body for a set of recommended standards.
- Incremental improvements – aim to continue or improve previous trends.
You can also set arbitrary goals and adjust them as you find out more about what works.