Figure 1: Energy monitoring equipment and software enable users to compare consumption of equipment and facilities by time, department, application, and more (top). The data can also be cross correlated (bottom) to discover opportunities for savings.
Cost savings through energy management delivers an important benefit to the organization as a whole, yet all too often, it is ignored. To some extent, a disconnect exists between the part of the organization that would benefit from lower TCO and the engineers and purchasing staff responsible for buying, installing, and maintaining the equipment. Their biggest concerns are factors like overall equipment effectiveness (OEE). The utility bills don’t appear on their budgets. There is good reason, though, for staff like engineering and maintenance to care about this type of functionality.
Variation in power and energy demand across facilities, production lines, equipment, and operators provides insights into the performance of equipment and staff alike. Having the basis of comparison that comes from energy monitoring can simplify the job of engineering and help them achieve their goals.
- Engineering: Differences can highlight variations in the way equipment is assembled and maintained. They can reveal that new equipment is underperforming, flagging the need for additional fine tuning. Variations may even be as simple as environment conditions.
- Maintenance: Changes in energy consumption can support predictive maintenance. The current draw from a conveyor motor might rise because the belt needs to be adjusted or replaced. It could also indicate that the motor is nearing end of life. This type of information helps minimize faults and avoid costly downtime.
- Operations manager: Variations from factory to factory or shift to shift can show the benefit of specific techniques for the need for additional operator training.
Getting started
By now, you might be sold on the benefits of the technology. You probably also have a lot of questions, like how hard will it be, how expensive will it be, and where do you start? Let's begin with the latter question. The first step to accruing these benefits is to establish a baseline. For that, you should first turn to your electrical utility company. Typically, it can produce reports that can be downloaded and used as input for more detailed analysis. Next, you need to begin gathering data from your equipment and facilities.
It’s essential to have a plan. The goal is to pinpoint where energy is being consumed, and to gather data in a variety of ways so that you can correlate it and reach conclusions. One method is through power monitoring. Apply a current transducer to your load, whether that is the incoming feed of a building, a line, a machine, or even a motor. Granularity is important. You need to gather information in enough detail to isolate problems and pinpoint adjustments and improvements that can be made.
Don’t over complicate matters. One of the most common pitfalls in energy monitoring is to assume that monitoring requires an investment in all new smart equipment. That can carry a daunting price tag and present a large barrier to entry. In reality, you can get very good results just by applying monitoring equipment and sensors to your existing assets to determine which are underperforming.
In addition to electricity use, companies should measure factors like airflow, temperature, and pressure. If the airflow in a compressor drops, it could be caused by a leak but it could also be a problem with the motor or valves. If the process primarily requires low flow rates, this can identify an opportunity to replace a fixed-speed AC induction motor with a motor driven by a variable-frequency drive. This eliminates the need to run the motor at full speed all of the time, reducing wear on the motor, bearings, and power-transmission components. And, of course, there is always the classic example of the compressor that fails to shut down properly and runs overnight, consuming power without doing any useful work.
A similar exercise can be conducted with water and even natural gas. These factors are encompassed by the acronym WAGE: water, air, gas, and electric. The goal is to create a map of what your demand is, how it changes over time, and how you can control it.
Converting data into insight
It takes more than data to identify energy waste. It’s important to have effective analytic tools that can monitor and compare performance on multiple levels. This should go beyond just viewing equipment demand over time. It should compare consumption between facilities, lines, machines, even axes. It can evaluate performance on a shift-to-shift basis, to search for differences not just among operators but environmental conditions, or even power-quality issues that might arise. In other words, it should take the aggregated intelligence and make it actionable.
