Boosting energy management in food and beverage production
20 August 2018
To reduce energy use and create an effective energy-management strategy, Phil Kaufman, energy technology manager, Rockwell Automation, says manufacturers should take four key steps – monitor, analyse, control and sustain gains
Competitive pressures, tighter margins and rising energy costs are forcing manufacturers to alter their historical approach of treating energy usage as an unmanaged business expense. While electricity is the largest energy cost for most food and beverage plants, it offers the greatest opportunities for saving and can deliver fast payback.
Manufacturers need information about where, when and how much energy is being consumed and need to be able to act on that information. They can then develop an integrated energy-management program based on accurate consumption, spending patterns and demand profiles.
At the heart of an effective monitoring program is a network of digital power-monitoring devices that capture and communicate energy-consumption information. These devices measure energy parameters associated with a specific system. Monitoring systems for food and beverage manufacturing can include power, natural gas, water and wastewater.
Plant managers can gather detailed information on power consumption – from specific machines to individual product lines. Often a plant manager is surprised to find that 60 to 70% of energy is being consumed when no production is running. Understanding the true base load or fixed portion of energy consumption is a good place to start. In addition, managers can gain access to power-quality information that can increase productivity and lengthen equipment life.
Monitoring systems provide the foundation for accurate collecting and reporting of energy data. However, data analysis enables plants to make better decisions about controlling their energy costs.
Energy-management software can act as a centralised database for all accessible energy parameters within a facility or across multiple facilities. Software can help workers see problems that might exist and lead them to the proper corrective actions. This same software allows manufacturers to model their energy profiles by measuring peak demands and power-quality parameters, determining demand patterns, matching energy consumption to weather patterns, aggregating loads and calculating energy costs.
Effective analysis can only happen if data can smoothly flow from plant floor to top floor. The key to a successful energy-management system is integration of power monitoring, control devices, communication networks and visualisation technologies into a unified system that relates energy consumption to plant activity.
This plan relies on an integrated network architecture based on open standards, which allows users to deliver energy information across the enterprise. This architecture enables communication using a variety of open networks, such as EtherNet/IP and DeviceNet, via wired or wireless devices for faster data transfer and easy integration with existing networks.
After analysing the data, plant managers can develop an action plan and install automation systems to capture energy savings with a control system. Based on the energy goals of the plant, control systems can be deployed to yield different results.
For example, plants that want to maintain a more consistent level of energy use over time can deploy a load-management system to monitor the electrical consumption of selected equipment, and turn them on and off to minimise peak demand. Food and beverage plants that want their processing and filling equipment to become 'energy aware' can program equipment to turn off air supply lines when product is not being produced. Compressed air control and optimisation systems control the starting, stopping, staging and blowoff functions of an air compressor system, helping to achieve energy-management goals.
Once a manufacturer understands where energy is being consumed and effectively reduces that amount, the goal is to sustain those gains. That is not easy. Plant operations can change a plant’s energy profile and mask the true gains made by an energy-management program. When data is not tracked and related to production output often enough, it can appear that the initial energy-consumption investments are not paying off. To keep an energy program on target, several methods can be useful:
• Continue to reinforce energy as a priority in operational decision-making
• Communicate program successes as they occur
• Extend power- and energy-monitoring solutions to support continuous-improvement efforts
• Hold monthly reviews of critical energy KPIs
• Conduct an annual energy-management system assessment to help assure the program is following the plan set by management