- Energy-management programs should incorporate elements of industrial process control.
- Monitor energy use in the production area to identify waste and implement savings opportunities.
- A successful energy-management program requires the cooperation of all production staff.
The wide variety of energy-intensive processes in manufacturing facilities makes tracking and managing energy use a challenge. While energy costs can be significant, often little attention is paid to how that energy is used in production. There are a host of energy-saving opportunities for manufacturers, but a lack of knowledge can hinder the ability to take advantage of these opportunities. To manage energy costs effectively, it is important to measure energy use throughout the facility, identify waste and takes steps to improve efficiency.
Measuring for control
Conventional energy-management programs focus primarily on building-oriented systems, such as lighting and heating, ventilating and air conditioning (HVAC). While these are important, the majority of energy use in a typical manufacturing facility is devoted to production. To optimize savings, the energy-management process should incorporate elements of industrial process control as part of a program to improve efficiency.
The energy-management process should also integrate the energy cost element into production area planning for continuous improvement in total manufacturing cost control. Analysis of data from production area voltage meters, as well as temperature and flow sensors can provide process accountability, monitoring and control. Each department must realize that energy use is integral to their total cost. Moreover, they need real-time data in order to identify waste and make improvements in a timely manner. Unnecessary energy use in production processes should be eliminated wherever possible.
Energy-saving measures for production facilities
Manufacturing processes are diverse. Cost-cutting measures for a variety of industry segments and applications follow:
- Finishing operations. Minimize paint booth length and cross-sections to reduce air supply and energy use while maintaining proper air flow.
- Machining operations. Install control valves in the coolant supply piping of each machine to feed coolant only when the machine is in operation. Determine the optimum coolant amount by checking the lowest allowable pressure that does not negatively impact tool life.
- Refrigeration systems. Install variable speed control drives on evaporator fans to reduce energy costs; only using refrigeration equipment when needed.
- Robotic systems. Hydraulic and electric robots are widely used in manufacturing facilities. Hydraulic equipment for robots must operate whether the unit is in motion or idle; wasting energy. Electric robots use up to 70 percent less power, depending on the task.
- Cleaning operations. Use an electric timer shutdown circuit to reduce the run time of spray wash pumps, which normally operate (and consume energy) continuously.
- Drying equipment. Minimize heat loss with proper insulation. Also, adjust operation flow to ensure that parts arrive at the drying station as warm as possible.
- Process heating. Replace steam systems with energy-efficient, direct-fire gas technology for savings of 33 to 45 percent, depending on the application.
Many energy-saving measures cut across a variety of industries. For example, replacing pneumatic tools with gages, drives and controls can reduce the need for compressed air—a very expensive utility. Energy-management solutions also incorporate high-efficiency motors, improved power quality and peak demand reduction.
Training and employee cooperation
A successful energy-management program requires the involvement of all production staff. Train employees on how to operate equipment efficiently, and encourage them to look for energy-saving opportunities. Form work groups to continually fine-tune equipment operating parameters, such as run time, flows, pressures, temperature and humidity. Input and cooperation from well-trained, experienced employees is critical in reducing energy waste and finding ways to improve overall efficiency.