Uncovering Hidden Sources of Energy Waste

With a combination of instrumentation, analytic tools, and a little help from the utility company, you can cut operating costs while simplifying maintenance and reducing downtime.

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In an increasingly competitive marketplace, more is the mantra: more productivity, more throughput, more profitability. But what if the easiest route to more is actually less? By analyzing your operation to discover facilities and equipment responsible for unnecessary energy consumption, you can do far more than lower your utility bills. You can find ways to improve procedures, optimize operator performance, track equipment health to prevent failure, and in general boost the performance of the entire organization.

One of the key goals of energy analysis is to find equipment consuming power unnecessarily and squandering money (see figure 1). This can range from fans and compressors left running when they should be turned off to pumps powered by a combination of fixed-speed motors and mechanical valves rather than a variable-speed motor that consumes less power. These types of issues combine to inflate cost of ownership of the equipment unnecessarily.

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.

Figure 2: Demand analysis makes it possible to compare the actual performance of equipment to the desired performance on a real-time basis.

Deep, granular analysis can deliver surprising insights. In general, most of the equipment runs well but certain pieces of equipment will emerge as unexpected energy consumers. A stamping machine might have had a one second or even a half second idle phase programmed into its cycle, for example. The period of time is too short to be noticed by an operator but long enough to consume a noticeable amount of extra energy compared to similar equipment.

The analysis tools can be used to drill down to deliver not just energy usage by machine but energy consumed manufacturing different products. That can lead to changes to procedures or even a more accurate assessment of the profit margin of a product line.

Just monitoring performance isn't enough. It needs to be transformed from actual conditions into the ideal conditions. Once an asset has been identified as a problem, the goal is to establish an optimum energy footprint for the asset and maintain it at that level. That can be done using tools like smart breakers or analog input and output modules. These devices can control the temperature in a given sector at the same time they are monitoring it.

Implementing energy visualization might sound complex but it can be surprisingly easy. More to the point, it’s very cost-effective, with companies realizing ROI in as little as six months. Work with your vendor to combine data from a baseline audit with some use cases to get buy-in from key stakeholders. The results will benefit your entire organization, top to bottom. For more information, click here.

Further reading:

e-F@ctory

e&eco-F@ctory

Previous issues of Creating Productivity

Making the Factory of the Future, Today

Cutting Total Cost of Ownership

Taming the Data Monster

Meet the tools:

EcoWebServer III

EcoWebServer III from Mitsubishi Electric Automation is an energy-saving data-collection server that collects, analyzes, and acts on data aggregated from the smart factory floor. It features a GUI with preconfigured or customizable reports that make it easy to visualize and assess energy data over a user-defined time interval ranging from monthly to minute by minute. The device can send alarms when assets exceed triggers. It supports both comprehensive electrical metering and sensors for non-electrical utilities such as for water, gas, steam, compressed air, temperature, and pressure.

On-board memory enables EcoWebServer III to store data for as long as five years, depending on the sampling interval. It can be exported via CSV file. The Web server interface enables simultaneous use by personnel throughout the organization.

AX Energy

Conserving energy is the right thing to do, both environmentally and economically. Given the amount of data and the complexity of the analytics involved, however, it can be challenging to pull off. Enter Mitsubishi Electric’s AX Energy, a web-based energy-management application that can slash utility bills by up to 25% annually. Designed for easy deployment and fast ROI, it analyzes the output from thousands of meters to present key performance indicators in a rich visualization environment. The Site Summary Overview, for example, presents details of overall energy consumption, cost, and carbon footprint. The ISA95-compliant Asset Tree feature makes it easy to drill down to reports and charts for equipment and locations throughout the operation. Because the application is web deployed, users can access it from a range of platforms, including PCs, mobile phones, tablets, and HMIs. It’s available out of the box with preset calculations that can be easily customized to suit specialized requirements

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