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Automating Energy Consumption

Plants are turning to automation tools to drive down energy costs and reduce carbon emissions.

The University of Cincinnati was faced with upgrading its aging facilities management equipment that provides heat and cooling for 100 buildings across 420 acres. The university uses three central utility plants that deliver 635,000 pounds of steam per hour for heating, and 22,000 tons of chilled water for cooling. The facilities management department wanted to convert from its proprietary distributed control system to an open control system. The department also wanted to create a network of controllers that would make heating and cooling more automated and more efficient.

The department chose Wonderware to run the new control system. “We chose Wonderware software because we thought it would be easy to install and let us mix our existing equipment with new equipment,” says Everett Wolverton, associate director of facilities management at the university. “It also suited our long-range plan to integrate the campus for better energy accounting systems, which would let us better match production capabilities with what’s actually used on the campus, and increase our overall efficiency ratings.”

Quick payback

By adding new equipment and installing an automated control system that monitored energy use and reduced waste, the university was able to trim its energy consumption by 15 percent. The savings amounts to $1.8 million per year, delivering a quick payback on the control system upgrade.

With rising energy costs and the growing interest in reducing carbon emissions, plants are becoming more interested in making their facilities more energy efficient. And plants such as those at the University of Cincinnati are discovering they can use automation technology to drive down energy consumption.

When energy costs were lower, and plant managers didn’t give a lot of thought to carbon emissions, energy efficiency wasn’t much of a concern. Companies worked hard to drive down the cost of raw materials, but energy consumption was mostly ignored. That has changed dramatically over the past three years. Companies are beginning to realize their energy costs are spiraling out of control. “In a survey, Fortune 500 companies were asked what part of their expenses did they have the least control over. It was energy costs,” says Andres Thorarinsson, chief executive officer of Vista Engineering, in Reykjavik, Iceland. “Energy is getting more expensive, so there is more interest in controlling it than ever before.”

Plants are becoming much more aware of their energy use, partly because of the rising costs of energy and partly because of the growing concern over carbon emissions and the environment. “You can’t really separate the two—energy reduction for cost savings and sustainability,” says John Nesi, vice president of strategic and segment marketing for controls vendor Rockwell Automation Inc., in Milwaukee. “They are not going to do the energy reduction unless they see it as a good business practice. And energy reduction becomes important as companies look at their operating variances in energy costs.”

Energy consumption is becoming important in most industries, though the effort to contain energy costs is particularly important in the heavy industries such as pulp and paper, automotive, steel, and oil and gas. In the retail industry, companies such as Wal-Mart Stores Inc., the giant Bentonville, Ark.-based retailer, are putting pressure on the entire supply chain to improve energy efficiency. In pharmaceuticals, energy tracking and control fits in handily with the need to monitor and sustain consistent temperature and humidity. “Pharma is ahead of the curve on energy monitoring because of the need for product quality,” says Harvey Eure, product manager for enclosed drives, at automation vendor Schneider Electric, in Palatine, Ill.

Tracking and monitoring

One of the critical requirements to reduce energy consumption is the ability to track and monitor energy consumption. You can’t reduce what you can’t measure. “Ninety percent of companies don’t know how much electricity it takes to make their products,” says Chuck Miller, director of solutions development for vendor Johnson Controls, in Milwaukee. “One plant has one meter that tracks 25 different processes, so no one at the plant has any idea how much natural gas, electricity or steam they consume per product.”

Many companies are turning to formal energy audits to get a handle on energy usage and potential energy savings. In the past, with low energy costs, tracking energy consumption and tying it to product costs was not much of a concern. That’s changing at most large plants. “Companies are hiring energy managers to analyze energy use in the building and do an energy audit,” says Schneider’s Eure. “They usually recommend replacing boilers and lights, and switching to variable-speed drives.”

Surprisingly, not all plants are implementing even the simplest form of energy tracking. “A lot of companies that use automation for monitoring and control are still not gaining an understanding of their energy output,” says Alison Smith, senior analyst at AMR Research Inc., in Boston. “There are a lot of opportunities to do energy consumption monitoring and analysis. I wish more plants would do it.”

To some extent, the value of tracking and monitoring energy consumption with the goal of reducing consumption depends on the amount of energy a plant consumes. “We choose our clients by the amount of energy they use,” says Thorarinsson, of Vista Engineering. “We target those spending $100,000 or more per year in energy. At $50,000 in energy spending, it may not be worth the investment to track and reduce consumption.”

Energy savings tools

There are a number of strategies companies are using to reduce their energy costs and carbon emissions. One is choosing energy-efficient equipment. Energy savings has become a competitive feature on new plant equipment. “One of the criteria in choosing equipment is energy consumption,” says Atle Bjanes, principal engineer at Gradient Engineering, in Lititz, Pa., a company that helps plants deploy energy reduction automation. “I haven’t seen it yet, but I expect energy consumption to become one of the deciding factors in choosing equipment.”

Another strategy for reducing energy costs is peak load reduction. That means buying energy when it’s cheap, during the night when the load on the energy grid is lowest and the cost also lower. “One trend we’re seeing is that manufacturers are seeking a reduced rate in energy costs through off-peak usage,” says Harry Forbes, senior analyst at ARC Advisory Group Inc., in Dedham, Mass. “All kinds of manufacturers are looking at the value of load-shedding. They replace or recharge a thermal store during off-peak hours.”

Yet another way to save is by using variable speed motors. The idea is that variable speeds allows the motor to gear down to a slower speed—and consume less energy—when full speed is not necessary to get the job done. “Sixty percent of the energy used in manufacturing is in rotating a motor,” says Rockwell’s Nesi. “We’re seeing more and more people going to variable speed technologies as power management solutions.”

Whether a company is interested in cutting energy costs or being a good corporate citizen regarding the environment, there is growing interest in reducing energy use at plant facilities. The keys to that reduction include tracking, monitoring and controlling energy use. Many plants are turning to the technology tools they already have in their control systems in order to reduce energy consumption and carbon emissions.

Source: Automating Energy Consumption, March 2008 (p.43), Written by Rob Spiegel, Contributing Editor
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