A highly industrialized nation, the Untied States' industrial sector currently consumes more natural gas than any other end-use sector. Manufacturing consumes more than a third of all energy used in the U.S. each year. Particularly energy-intensive industries include petroleum refining, steel manufacturing, aluminum manufacturing, paper manufacturing, chemical manufacturing and cement manufacturing.

For many of these industries, energy costs make up a large percentage of total operating costs. According to The Need Project, energy accounts for 43 percent of petroleum refineries' total operating costs. In steel manufacturing, energy makes up 15 percent to 20 percent of the total cost of making steel. For manufacturing aluminum, electricity constitutes 30 percent of total production cost.

Despite making strides in reducing energy consumption in recent years, companies in these industries are still spending a lot of money on energy usage. In a recent Aberdeen Group survey on energy management, 80 percent of respondents said reducing costs was the biggest driver for implementing energy management programs.

Because energy costs are often upwards of 25 percent of the plant's total operating cost, "the ability to cut even a small percentage of total energy consumption can result in significant savings for the organization," the Aberdeen Group says (registration required). In the Aberdeen survey, "best-in-class" companies were able to reduce energy consumption by 15 percent year over year and have overall equipment effectiveness at 90 percent because of energy management programs.

Before starting an energy management program, however, plant engineers must first assess how much energy their facilities are consuming and how this energy is being used, Control Engineering advises. This can be done by working with local utilities and using energy measurement devices. The U.S. Department of Energy's Industrial Technologies Program also offers an online tool that helps industrial plant personnel diagnose how energy is being used and where there's potential to save energy (and money).

Once engineers have a clear picture of the energy flow in their plant, they can tailor the management system to their plant's functions. Here are some general ideas for managing and reducing energy usage.

Install Energy Management Systems
Energy management systems allow companies to monitor energy use and cost. This information enables management to optimize production processes and scheduling accordingly. It also allows for measuring the energy management program's performance, Aberdeen notes.

Use the Right-Size Equipment
"Stop over-sizing drives and motors," Control Engineering advises. "Check the load requirements needed for a particular project to maximize the potential of the drive." Don't oversize a system to design for "future capacity" or "just to be sure," Plant Engineering adds. Also, ensure blowers, pumps, air compressors, hydraulic systems, dust collectors and chillers are up to current energy standards.

Choose the Right Components
Motors are one of the top three sources of industrial energy consumption, so a considerable amount of attention should be focused on this area, Control Engineering recommends. Plant managers are advised to use variable frequency drives to eliminate a high in-rush of currents when motors are started, because these bursts can sometimes push plants to a higher rate bracket as utilities tend to contract rates based on demand. Control Engineering also suggests using fin-less drives to reduce cabinet size and the amount of cooling needed.

Run Equipment as Needed
The duty cycle is the amount of time equipment is working divided by the total operating time. In some plants, duty cycle can be as low as 25 percent, Plant Engineering says. The simplest solution is to turn the equipment off or slow it down when it isn't working so it doesn't waste energy. Heatsink fans for motors and drives can also be sequenced to turn on or off depending on use, thus reducing the use of unnecessary power.

Monitor Maintenance
Dirty air filters can add load to fans and improperly tensioned V-belts can reduce transfer efficiency from 97 percent to 88 percent, according to Plant Engineering. Make sure all equipment are functioning properly and fix the ones that aren't.

Don't let the initial costs of investing in upgraded systems, components and equipment be a deterrent to implementing an energy management program. In the long run, the savings in energy will pay for those initial costs, Plant Engineering explains.

Perhaps most important for energy management to succeed, companies must have an energy management leader who is supported by senior management, Plant Engineering says. Having an energy champion spearhead the program ensures the company stays committed to energy management.

See also

Old Sources for New Savings

Getting Serious about Energy Efficiency

Resources

Energy Management: Driving Value in Industrial Environments
by Mehul Shah and Matthew Littlefield
The Aberdeen Group, April 2009

International Energy Outlook 2009
Energy Information Administration, May 27, 2009

Intermediate Energy Handbook: Energy Consumption
The Need Project, 2008

Energy Management: First Steps Toward Greater Efficiency
by David Greenfield
Control Engineering, Jan. 1, 2009

Effective Energy Management Saves Money, the Environment
by Ted Clayton
Plant Engineering, May 1, 2009

Industrial Technologies Program Software Tools
U.S. Department of Energy