Driving Manufacturing Competitiveness Through Energy Awareness

Transcription

1 Driving Manufacturing Competitiveness Through Energy Awareness Phil Kaufman, Rockwell Automation Regardless of segment or industry, most Operations teams have one thing in common: They re being asked to cut expenses from already-trimmed operating budgets. With the easier-to-cut line items long gone, teams need to start exploring new improvement opportunities, including energy management. This paper describes a new, non-disruptive approach for collecting data from energy-intensive assets, and explains how Operations can use its existing optimization tools to reduce consumption all without compromising production.

2 2 Driving Manufacturing Competitiveness Through Energy Awareness A New View of Energy Under constant pressure to squeeze more out of their operating budgets, manufacturers often turn to their Operations teams to drive innovative improvements that lead to cost savings. Known for constantly seeking savings in everything they do, Operations teams are constantly investigating ways to increase throughput, improve quality, reduce waste and optimize labor. The Power of Information Despite the success of these efforts, management continues to increase its expectations, demanding further reduction in operating expenses while maintaining or even increasing production. In the past, achieving these goals has been accomplished through a combination of equipment upgrades, Lean Six Sigma processes and other incremental improvements. Today, the low-hanging, expense-reduction fruit has long been picked. Continuing to beat the numbers will require the Operations team to take a new approach one that considers the role of energy within the operations Undoubtedly the Facilities team already has done all it can to reduce energy costs. For example, it has likely taken advantage of multiple utility rebates to retrofit shop lighting and motors. It has updated HVAC systems, upgraded to more efficient air compressors and chillers, even added variable speed drives. It may have even worked with the local utility to generate payment for demand response. Putting manufacturing productivity at risk to figure out how to save energy isn t a favorable option, and no one is going to agree that turning dials to save nickels is worthwhile. But what about leveraging the Operations team s vast experience to analyze energy as production data? It s now possible using new, non-disruptive methods for accessing energy-consumption data from within existing automation systems. The good news is that it doesn t require an advanced degree in power quality. It simply requires engaging the people within the organization that look at efficiency every day of the week the manufacturing support teams. Energy Awareness: The Answer Lies in Data Like any useful analysis, effective energy awareness requires having the right information at the right time in the context of what s happening in production. To reveal this level of insight, many manufacturers have implemented a top-down approach, analyzing energy-consumption patterns versus production output to determine how operations impacts energy usage. For manufacturers that produce a limited product line, these consumption patterns are less complex and are easier to detect, making it possible to accurately predict energy for procurement, production scheduling and sustainability objectives. However, the effectiveness of the analysis generally falls short when more complexity is introduced with more product types, where too many factors exist to accurately assess consumption patterns. The impact of nonproduction energy consumption further complicates the ability to correlate energy usage patterns against production schedules.

3 Driving Manufacturing Competitiveness Through Energy Awareness 3 A common alternative is a bottom-up approach focused on metering energy at the point of production using an energy-management system. While this approach provides accurate, detailed data, it also can be disruptive to production, complicated to execute, and often requires a significant investment with an unclear return. Now, the availability of easily accessible data sources from energy-aware devices and systems offers a more effective view of energy as production data. This level of energy information helps enhance the data already being collected with top-down and bottom-up approaches. Some level of energy metering most likely already exists within newer motor control products. Traditionally, this information has been used to more efficiently control motors, but now it can be extracted from the system and analyzed at minimal cost and without affecting production. Leveraging this information more easily gives a granular view of energy as production data. Coupling these accessible data sources with more traditional top-down and bottom-up approaches helps isolate energy usage on the factory floor. As a result, energy consumption can finally be understood in the context of manufacturing, and energy becomes just a manufacturing data point. The team can use energy-consumption data as they would any other production metric to make adjustments to production and machines. Gather the Data: Connect and Collect Using energy data to reduce consumption in an impactful way requires an rule focusing on the highest consuming assets to net the greatest results. An ideal place to start is collecting energy-consumption data on high-horsepower motors. This data can help the Operations team identify the top energy-consuming assets, and later prioritize improvements that will have the most significant impact on cost savings. Energy-aware capabilities enabled by motor control technologies allow non-disruptive extraction of energy-consumption information with minimal impact to manufacturing. The addition of an automation controller as a data concentrator on the plant s EtherNet/IP network allows operators to gain access to the consumption energy, collect the energy attributes, and store the data in a historian for further analysis all without touching the asset or process. Given the advancements in automation technology, this capability is being embedded into motor control technology for easier access. Move From Easy Wins to Insight-Based Improvements For many years, energy management revolved around finding the easy wins. Auditors were hired to walk around and collect data. The recommendations resulting from their analysis often were akin to reminding family members to turn the lights off when they leave a room. They often struggled to add business value because they weren t fluent with the plant s production processes.

4 4 Driving Manufacturing Competitiveness Through Energy Awareness By being able to view energy as an element of production, manufacturers use existing expertise and tools to reduce consumption and move beyond the easy wins. Today, in-house engineering staff can examine energy in the context of production and use standard optimization tools, such as Minitab, to pinpoint specific areas of concern. By being able to view energy as an element of production, manufacturers use existing expertise and tools to reduce consumption and move beyond the easy wins. Converting energy to a cost per production unit, which can be easily added to Lean Six Sigma tools like value-stream maps, allows the team to find answers to a number of questions, such as: Should WIP be used as a battery to store lower-cost energy for when rates are high? Should equipment be left on and thereby consume energy until the next run because of the time it takes for the equipment to return to the required temperature? Can a series of operations be sequenced to take place at times of lower energy demand and still meet production schedules? Define Meaningful Energy-Performance Metrics Manufacturers may have more efficient equipment, but are they running them smarter? When it comes to optimizing energy consumption and identifying cost-saving opportunities, the greatest level of success will be achieved by tracking two metrics: energy consumption per production unit (intensity) and operational energy performance (efficiency). Manufacturers can use these metrics to pinpoint the best return on investment and set baselines for the following key production metrics: Energy consumption per production unit Use this metric to identify the energy intensity (its contribution to overall cost) and to set baselines for measuring improvements. By understanding the extent to which energy contributes to the cost of a particular asset, unit, cell or process, Operations can determine whether further investigation is needed. Remember the rule and start big! Intensity = kw / unit of production Operational energy performance This metric helps assess the amount of energy consumed at the time of manufacturing against the total energy for a period of time. Ultimately, this helps determine how efficient energy is being consumed at a given point in manufacturing. Only energy consumed during production should be considered as operational energy and applied to the numerator. Changeovers, quality holds, machine jams and lunch breaks are considered non-production energy and will only be applied to the total energy per period. Efficiency = Productive Energy / Total Energy

5 Driving Manufacturing Competitiveness Through Energy Awareness 5 Consider two common scenarios and how these metrics can help the team focus its efforts: The following chart demonstrates inefficiencies throughout the day. Large efficiency swings are the next generation of low-hanging fruit and generally expose behavioral changes. Employee training, re-sequencing of an operation or changes to production schedules may result in energy savings. Lunch breaks, morning start up and end of shift have the greatest impact on the lines efficiency and can point to equipment improvements to place them into a lower energy state during periods of non-production. Changeovers are typically considered productive energy and improvements to changeovers will reduce intensity but may not increase efficiency. For example, see how at 9:00 the intensity goes up but the efficiency remains relatively flat. The second chart shows a higher efficient usage of energy in production. These areas tend to be related to type of equipment used rather than when it is used. Cost-saving activities are generally found in the area of equipment upgrades (drives, higher efficiency motors, insulation or higher efficiency heating/cooling systems), maintenance or the addition of automation. As with the first chart, low-power states during non-productive periods such as lunch, quality holds, or machine jams will always reduce energy costs.

6 6 Driving Manufacturing Competitiveness Through Energy Awareness Changes in interval periodicity bring other important factors into play. Longer periods such as per shift, per day, or longer can expose the impact of weather on energy consumption, what shifts are the most efficient, and how the fluctuating cost of energy impacts operating costs. It may even lead to innovations such as using work-in-progress (WIP) as a battery to store lower cost energy or operational efficiency based preventative maintenance schedules. Enhancements Behavioral or Automation? When implementing changes to reduce energy consumption, conventional wisdom advocates giving operators responsibility for making changes that can improve performance metrics, so long as the adjustments don t impact throughput or quality. If operators can make minor adjustments to net small savings, empower them with data/ dashboards. If the changes they make will affect throughput or quality, the best practice is to automate. High-risk processes or instances when traditional manufacturing metrics can degrade over time are good examples of scenarios when automation is prudent. Automation offers several benefits over traditional operatorcontrolled processes because it maximizes reliability and minimizes production risk. When operators are tasked with making adjustments, human error and behavior often mean that processes degrade over time and become less effective. This happens for a variety of reasons staff may willingly choose to ignore procedures, information may be lost during job transitions, or people simply forget the rationale behind certain process steps. Automation helps minimize variability and allows producers to make adjustments that will be automatically maintained over time. Consider these examples and how behavioral changes or automation may be applied to reduce energy consumption: An operation where energy consumption fluctuates from batch to batch and its efficiency varies from 30 to 60 percent. In this case, improvements should be focused on operator training, work instructions or material variation. Activities could be as simple as exposing key energy-related performance metrics to the operators on a machine s display. A manufacturer would leave equipment running overnight shifts to increase production throughput when staff arrived the next morning. A value-stream analysis was conducted to evaluate energy costs for production and nonproduction activities. The analysis helped determine that it was more economical to shut machines down and forego additional unit production as labor overtime charges were less costly than energy costs to leave machines running nonstop. The automation system was upgraded to implement a sleep mode for equipment rather than completely shutting down, ensuring availability of equipment and reduced risk to productivity and profitability. An operator on second shift always had the greatest throughput on his machine. After exposing energy consumption data on three of the highest consuming devices, it was discovered that the operator was running the process at higher than normal temperatures to produce more product. The higher manufacturing costs in energy intensity and maintenance exposed a negative impact to operating cost. Automating the process provided consistency and optimized energy usage.

7 Driving Manufacturing Competitiveness Through Energy Awareness 7 Energy Management Pro Tip: Successful energy managers focus on the 20 percent of the assets consuming 80 percent of the energy in manufacturing. Move Energy to the BOM After manufacturing energy-consumption data is stored and analyzed, clear trends begin to emerge. The Operations team gains insight into how energy has been used among various historical events, such as a specific product cycle or batch. Capturing this level of knowledge provides an immediate benefit and also promotes future improvement because Operations no longer has to guesstimate energyconsumption levels for similar production runs in the future. Empirically, tying energy-consumption requirements to the production bill of materials (BOM) helps the Operations team make proactive production decisions and better manage energy investments in a way that will generate a greater return. Benefits include predicting usage against production schedules, using schedules for energy-demand planning, negotiating better rates with utilities, and participating in the correct demandresponse programs. For example, knowing that certain batches require more energy allows Operations staff to schedule those batches outside peak demand times. Additionally, data, such as unit-level energy consumption, can become valuable input into a company s sustainability score cards and other reporting mechanisms. Take a New Approach to Energy in Operations As Operations teams continue to seek new opportunities to reduce expenses, they must think more holistically. Energy management presents one area of significant opportunity. Fortunately, the data necessary to take advantage of this opportunity are already available within existing automation systems. By tapping into commonly used automation technology to extract this data and using common productivity tools to interpret it, manufacturers can improve productivity, efficiency and reliability.

8 EtherNet/IP is a trademark of ODVA. Minitab is a trademark of Minitab Inc. Rockwell Automation is a trademark of Rockwell Automation, Inc Publication ENERGY-WP002A-EN-P February 2015 Copyright 2015 Rockwell Automation, Inc. All Rights Reserved. Printed in USA.