Whenever I show up at a new client’s, the first thing they pass in front of me is their “Energy Profile,” or “Energy Report,” or (and this is the most accurate title) “Energy History.” These plots show some form of energy consumption over some time period, usually electricity and natural gas over the course of a year. This is a logical place to start, and you can acquire some real insights.
Take a look at the chart on the left here. (This is all fabricated data by the way.) This chart shows energy consumed through a typical week for an injection mold machine making plastic chairs. So what do we learn? Well, clearly something different happened on Friday. Maybe there was an early shut down, maybe operators were just paying less attention. Something seems to have been happening on Wednesday as well. These definitely call for some investigation. If nothing else, we’ll understand the weekly cycle better.
But, really, this chart doesn’t give us any sense of how our production rate drives our energy consumption. In ISO 50001 parlance, we would say that Time is NOT a Relevant Variable. Our energy consumption does not change because Time is passing! Our energy consumption changes because OTHER THINGS are changing. In this case, it is Production.
Take a look at the second chart. Oh my! Now we seem to be getting some useful information! We can see now, not only that energy consumption is proportional to Production, but we can see HOW it is related to Production. We can actually determine the mathematical relationship between the two. That means that given Production projections, we can compute Energy Consumption projections! Isn’t that a grand piece of information to pass to your CFO? You can also now deliver an estimate of marginal energy intensity per chair produced. Be careful now! You are making yourself profoundly useful to your top management!
Finally, you can identify a key insight for your own energy improvement efforts. This relationship tells you how much of your energy consumption is related to Production, and how much is Baseload. I’ve seen places where a simple analysis such as this revealed that the Baseload was over half of their monthly energy consumption! They had been working diligently on reducing energy consumption in their Production processes, but it turned out that the Baseload was the elephant in the room.
They asked me, “Why is it so much?” I said that I surely didn’t know, but that they had better find out.
(And if you’d like to see what this feels like from the elephant’s point of view, click here: https://twitter.com/PaulBirkeland/status/240609468910563328/photo/1)