I was recently listening to a Podcast about rugby when one of the things that were being mentioned really struck a chord with me. They were talking about defence stats and how missed tackles aren’t necessarily a bad thing, it sounds counter-intuitive, but it makes sense when you think about it.
A missed tackle that slows a player down enough for him to be tackled by someone else could be better than a completed tackle where you lose 10 yards to a leg drive.
Similarly, when you are tracking your energy usage, you need to be aware of the context that is behind the data you are looking at or you risk misleading & incorrect comparisons. This blog should help you separate “Vanity” EnPIs from “Authoritative” EnPIs.
Vanity EnPIs
1. Average Total Energy Consumption – Just looking at the average consumed energy doesn’t tell you anything about how much energy you used at any specific time or how you would go about reducing it.
2. This year vs last year (unnormalized) – Without having some context (normalisation) you’re not comparing like with like. An increase or decrease in total energy consumption could be due to several reasons, such as increased production, expanded/contracted facilities, extra shifts, etc.
3. Interval Daily Data of Energy vs Power – When looking at longer time frames you will want to use Energy (kWh) as a comparison. But when looking at less-than-daily figures you may want to use Power (kW) to see what each piece of equipment is using in a shorter time frame.
4. Energy Consumption more granular than 15 min – Any smaller than 15-minute intervals and there will be too much information to look through for regular comparisons. There are certain applications which may require faster than 15 mins.
Authoritative EnPIs
1. Cost per unit of Energy – Can be used to determine when to run machines (load shifting).
2. Time of day & energy spikes – Avoid using energy at peak times. Excessive spikes can cause excess penalties to occur, can be easily avoided with the right equipment & knowledge. Analysing the time of day your energy is being used will also allow you to identify how each machine is affecting your energy consumption.
3. Energy Productivity – Energy per unit produced. Great EnPI to have for industrial companies as it shows you how much each unit you produce is costing you. Can be used to identify if the process isn’t running at 100% efficiency and detect faulty/at-risk machines.
4. Carbon Emissions – Carbon emissions will allow you to compare different fuel source types to really get to grips with how all your energy users contribute to your total energy consumption.
5. Energy consumption per business unit – Break down the cost of energy per each business unit you have. Could be different offices (m2), per person, or per production line (kg) for example. Great way to compare the different parts of your business.
Be wary of
1. Energy Use per change in Temperature – Energy use per Degree Day is one of the first comparisons that everyone does on their energy use. It is a great comparison to have when comparing a site to itself. The difference in humidity, wind direction etc can introduce inaccuracies to this EnPI if you are not careful.