Few topics raise the hackle feathers of political emotions as much as talk of “global warming” or “green.” Some people are passionate about conservation. Others are suspicious of an anti-business, liberal conspiracy. Putting aside politics, what companies are discovering is that they can be sensitive to the environment, earn credibility with the public for being good citizens and improve the bottom line—all at the same time.

People who have been implementing energy savings projects have discovered that no stone should be left unturned while looking for likely candidates for projects. Machine and process operations are often a good place to start. But the heating, ventilation and air conditioning (HVAC) systems can be a gold mine of cost savings, too.

Puzzlingly slow

One thing that puzzles many observers, though, is that with all the technologies developed during the past 15 years and the resulting publicity, why has adoption of energy-saving technologies been so slow. John Malinowski, motors product manager at Baldor Electric Co., an electric motor manufacturer based in Fort Smith, Ark., says that a big part of the problem is the way people are rewarded for job performance. For example, he says, of the total cost of an electric motor over its life, only about 3 percent is the original purchase cost. Upwards of 97 percent of the cost is the amount of electricity it will draw. The purchasing agent is not graded on this major part of the cost, however, but rather on just the original purchase price. It would take an executive level decision to change the system and make energy cost reduction a part of everyone’s job description.

Dan Cheung is senior process control engineer at Domtar, a pulp mill located in Kamloops, British Columbia, Canada. In one process, the mill burns calcium carbonate to make calcium oxide in a lime kiln with a capacity of 400 tons per day. “We were using 8.5 gigajoules per ton of energy on the system,” says Cheung. An industry benchmark survey showed the usual rate to be 7.3 to 7.4 gigajoules. He decided that action must be taken.

“We hired an energy auditor who checked out the conditions of the instrumentation and process and came up with a report that said an energy savings project was doable. In fact, they conservatively estimated that we could get down to 7.4 or 7.5 gigajoules. That would mean almost a million dollars per year savings potential. The three- to four-month payback was very attractive, so we proceeded,” Cheung says.

Working with Norpac Controls, a distributor of Emerson Process Management control products in Vancouver, British Columbia, Cheung initiated a project to implement model predictive control from Emerson on the mill’s existing Emerson Delta V control system. In addition to the software, Cheung also used this time to check and calibrate all the instrumentation. The resulting improvements were huge. “It is very cold today,” Cheung says, “yet, we are still burning at a rate of 7.2 gigajoules per ton. In fact, once the process stabilized, we found we could increase production by about 10 percent while still cutting the energy usage rate. These are very, very, very impressive results. It makes me look like a hero.”

Measure to control

Joel Shapiro, group manager for measurement and control at vendor National Instruments (NI), in Austin, Texas, says, “One thing that comes up in meetings with customers is that once people understand what they have, it helps them understand where to start. I just read a quote in “The Economist” regarding energy and greenhouse gas emissions that went something like, ‘If you start to measure, people start to reduce.’ We enable the measurement.”

NI customer Nucor Steel uses National Instruments’ CompactRIO programmable automation controller and FieldPoint input/output modules, along with NI’s LabView software, to reduce expenses running a furnace that melts scrap steel at its Marion, Ohio, plant.

Electrical Engineer Dave Brandt says a detailed economic justification in this case wasn’t much of an issue, because the cost of the NI solution was low. The system implementation began with a scrap weighing system. This piece of automation fed into process information. Knowing the amount of scrap steel going into the furnace meant that the amount of lime and other materials added to the mix would be more accurate. Further, energy input to the furnace could be better controlled so that operators don’t overmelt the steel. All of this adds up to fewer “pourbacks” to get the steel chemistry to the point that it will meet specification. “We ...