The more energy a plant consumes, the more important it is to look at how it’s used and wasted. Even small improvements in industrial energy efficiency can yield significant cost savings, reduce emissions and support sustainability goals.
This blog explores how a close look at energy consumption will help achieve higher operational efficiency in manufacturing. It also looks at the potential impact in terms of green manufacturing practices and discusses how the maintenance team can contribute to these efforts.
Understanding industrial energy consumption
The start point for any improvement effort is to establish a baseline. Manufacturers that have implemented the ISO 14001 standard for environmental management have a head start on this as they will already have measurement systems in place.
The next step is an energy audit. This will identify the processes and equipment responsible for consuming the bulk of the energy used. For most manufacturers, HVAC, boilers and motors will top this list, rivaled in some energy-intensive operations by furnaces, ovens and driers. Air compressors and lighting can be other significant contributors.
For a more granular look at particularly energy-intensive activities, flow meters (for gases) and current monitors (for motors) will provide the information needed.
Strategies for enhancing industrial energy efficiency
While targeting the highest usage equipment first, it’s important not to overlook the “low-hanging fruit” that can easily be picked off. Three proven strategies for increasing energy efficiency in manufacturing are:
- Optimize HVAC and lighting: Start by looking at usage patterns and ensure systems are shut off or turned down when not needed. (If a plant doesn’t run on weekends, for example.) Timers and motion sensors are inexpensive ways to reduce consumption.
With lighting, switch to higher efficiency fluorescent or LED when replacement is needed, but note that unless revamping a large area, discarding functioning units may not be very “green” or cost effective. Look for opportunities to use natural light where possible, (which is mostly in office areas).
- Switch to high-efficiency motors and drives: From the HVAC system and air compressors to the motors driving machine tool axes, almost everything in the modern factory is directly or indirectly powered by electricity. Replacement with variable frequency drive (VFD) motors will yield substantial energy savings, but the most cost effective energy efficiency management approach may be to mandate the use of VFD motors on all new equipment.
- Smart grid and renewable energy integration: In many regions, electricity is priced on peak demand. Adopting technology to lower this peak and adjusting working patterns to suit can make substantial inroads into energy costs. In parallel, explore opportunities to generate power on-site: solar, wind, biomass and geothermal should all be considered.
Integrating technology into energy management
Despite their good intentions, relying on humans to make energy conservation decisions is unlikely to be very effective. A better approach to tackling energy efficiency in manufacturing is through automation.
As mentioned, timers and sensors are cost-effective tools for powering-down lights and HVAC systems, but these can be integrated into building management systems for greater impact.
On individual pieces of equipment, Industry 4.0 and IIoT technologies provide pathways to higher industrial energy efficiency. Together, these capture and report data on equipment operation and condition. This can be analyzed, manually or by analytics software, to identify energy-saving opportunities. For example, belt speeds might be reduced as inventory builds in one location, or fan speeds could be adjusted as humidity changes.
Best practices in energy management
While technology and capital expenditure can play important roles, there’s plenty of opportunity to improve energy efficiency in industry by applying some best practices. Every operation should consider the following points:
- Improve OEE: Overall Equipment Effectiveness (OEE) measures how well a business is utilizing its production assets. It takes into account quality losses, unplanned downtime and production rate. Anything below 100% indicates resources, including energy, are being wasted.
- Maintenance routines that reduce energy waste: Use the Computerized Maintenance Management System (CMMS) to generate work orders for jobs like replacing filters, inspecting insulation, and cleaning fan blades and lighting.
- Preventive and predictive maintenance: Unplanned downtime is extremely wasteful in terms of energy, as downstream equipment is often left powered-up while the breakdown is addressed. Preventive maintenance (PM) addresses this by reducing failure rates and increasing Mean Time Before Failure (MTBF), but predictive maintenance goes further. A predictive strategy involves monitoring key indicators of machine health, identifying when failure is imminent, and issuing work orders just before that happens.
- Behavior change and training for energy conservation: While human beings are fallible, (see the section on technology above), education on energy consumption can still bring about more efficient behaviors. Explain how small changes in routines or habits can result in significant cost savings and sustainability improvements.
- Proper inventory management: Inventory occupies space, which requires heating and some lighting. Raw materials and finished goods inventories are set by business and operational needs, but spare parts inventory management offers an often overlooked opportunity. A poorly managed storeroom will often hold obsolete spares and even spares for which the original equipment has been sold or scrapped. A rigorous look at this inventory can often find ways to save space, while potentially improving availability of essential spares in support of more effective PM.
- Optimize facility scheduling: Changing work patterns can often lead to substantial energy savings. For example, adjust shifts to run through breaks, then shut down the line when it isn’t needed. Alternatively, schedule breaks to reduce energy demand at peak times. Look for ways to schedule PM that reduce energy waste.
Benefits of reducing energy consumption
Increased energy efficiency leads directly to cost savings that benefit the bottom line. Indirect benefits may also be seen in terms of improved quality and less unplanned downtime.
Using less energy directly translates to a smaller carbon footprint, (unless that energy was generated on-site by renewables). For any business that has implemented ISO 14001 and established goals for sustainability, this is an important step, although it should be seen as an ongoing process and not a one-off initiative.
Maintenance can support energy efficiency
Improving industrial energy is about more than chasing “green” goals, though these are important. It leads directly to cost savings that help build a stronger competitive position.
The maintenance team has an important role to play in raising efficiency. Their contributions include implementing energy-saving devices and technologies and supporting efficiency, productivity and OEE improvement. Many manufacturers turn to ATS for help with maintenance. This ranges from addressing short term spikes in workload to tapping into a variety of preventive maintenance services. Contact us to learn more.
