In our national debate about energy independence, fossil-fuel alternatives get most of the attention and the development dollars nowadays. Conservation efforts, meanwhile, get short shrift.
That's a shame. Conservation may not be as exciting as hydrogen cars or high-tech windmills, but it can offer immediate relief from our spiraling energy costs and reduce our consumption of fossil fuels. And one place conservation can make a much bigger mark than it has so far is on North America's factory floors, which are chock full of inefficient production machines, pumps, compressors, fans and conveyors. “There are a lot of dogs out there,” says John Malinowski, Baldor's product manager for ac and dc motors.
Improving the efficiency of these motor-driven systems could have a huge impact on energy use in this county. According to Paul Scheihing, an industrial technology manager with the U.S. Dept. of Energy's Office of Energy Efficiency and Renewable Energy (EERE), motor-driven processes don't consume the bulk of industrial energy. “About two-thirds of industrial energy consumption comes from thermal processes,” Scheihing says.
Yet, industrial motor systems do consume a huge amount of electricity. In 1994, the most recent year for which EERE has data, electric motor-driven systems consumed 23 percent of all electricity sold in the U.S., making them by far the largest single category of electricity end use. “That percentage most likely hasn't changed much since then,” Scheihing says.
A variety of technologies can help to reduce the energy consumption of motor-driven systems. Among them are more efficient electric motors and power transmission components, as well as using variable speed drives and regenerative power supplies where appropriate. These technologies are all mature, well-understood by engineers and low-cost when compared to the cost of an entire machine or system.
American industry's dirty little secret, however, is that it has under-adopted these simply energy-saving technologies. “There are still many untapped opportunities to save energy,” Scheihing says.
Rejecting Energy Savings
The reason why some of these technologies haven't taken hold to the degree they should comes down to how production machines and related equipment are bought in this country and how motors are specified in the field.
When interviewed for this article, engineers from motor and automation vendors — including Baldor, Bosch-Rexroth, Rockwell Automation, SEW-Eurodrive and Siemens — all pointed to a purchasing department mentality that has traditionally emphasized the purchase price of machines rather than the life cycle cost of running the machine. “A lot of companies haven't had a link between operations and purchasing,” says Karl Rapp, Bosch-Rexroth's applications manager for machine tools. As a result, even some relatively low-cost energy-savings components can be left off machines.
To take just one example, consider regenerative power supplies that reclaim energy from decelerating motor drives and that either reuse it or send it back to the power company. “They've been around for 15 years but very few applications are using them,” says Dan Throne, Bosch-Rexroth's sales and marketing manager for electric drives and controls. Regenerative capabilities typically only add between $500 and $1,000 to the cost of the power supply. “Purchasing has traditionally said, '$500? Get rid of it,'” Throne says. But on big production machines, regenerative systems can save thousands. Throne has seen cases where that “$1,000 adder saved $40,000 a year.”
Or look at induction motors, the most common type in the industry today. The National Electric Manufacturers Assn. (NEMA), the association representing most major motor manufacturers, has had specifications for a Premium Efficiency version of single-speed squirrel cage induction motors since 2003. These Premium specs cover an efficiency range from 82.5 to 95 percent, depending on the number of poles and other design factors. Across the board, though, the efficiencies are a few percentage points over standard efficiency and even high-efficiency motors that conform to the requirement of 1992's Energy Policy Act (EPAct).
Given the longevity and repairability of electric motors, the vast majority of the installed induction motors, of which there are in excess of 12 million, don't fall into the Premium Class, according to William Hoyt, the NEMA industry director for Premium Efficiency motors. “About 30 percent of new induction motor sales are Premium Efficiency,” he says. “But there are many, many standard efficiency motors in the installed base.” Baldor's Malinowski thinks the number of Premium Efficiency motors is lower than 30 percent, but he estimates 70 percent of new motors sold today meet either EPAct or Premium Efficiency standards.
The problem with increasing the share of energy-efficient motors, however, is that many are specified and bought by plant operations staff, rather than machine builders. Malinowski says about 90 percent of motor purchase decisions are made at the plant level. “That's why the repair-versus-replace decision is so crucial,” he says. NEMA's Hoyt agrees, “Our emphasis right now is on the repair-replace decision,” he says.
Design's Growing Role
So if purchasing departments can nix even an inexpensive add-on and a plant maintenance guy make many electric motor decisions, what role can machine designers play in energy efficiency? An increasingly large one, it turns out.
One reason is that existing and expected government regulations have started to favor efficient motor systems. The Energy Independence and Security Act of 2007, for example, mandates that by 2010 induction motors in the 1 to 200 hp range meet NEMAs Premium Efficiency standards.
Hoyt says NEMA members have also received an advance notice of a DOE rule-making that would establish efficiency standards for fractional horsepower ac motors. NEMA isn't in favor of the rules, he says. If this rule comes into effect, it would favor more efficient permanent magnet motors in appliance and small-machine applications where they are not used in any great number now, predicts Dan Jones, a well-known motor designer and president of Incremotion Assoc., a research firm focusing on the motion control market.
Bottom line is the regulatory trends will start to nudge designers of new equipment toward energy efficiency. “Pretty soon, machine builders won't have a choice but to design with energy efficiency in mind,” says Dave Grucza, a Siemens business development manager who focuses on energy issues.
And if regulations are nudging machine builders, the machine buying OEMs may soon start shoving them. The same suppliers who point to the old-school purchasing mentality note that over the last two years in particular, sophisticated machinery buyers have started to look more closely at life cycle costs when making purchase decisions. And they're asking their machine builders to deliver equipment that meets corporate energy-efficiency goals.
That's exactly what's happening at Ford Motor Co. According to George Andraos, the director of energy supply and efficiency for Ford Land, the company has improved the energy efficiency of its manufacturing efforts by 30 percent since 2000 and is on track to improve its efficiency another 3 percent annually for the next decade. The company has been carefully tracking the energy intensity, or energy used per vehicle produced, to create a baseline for its efficiency efforts. Some of those gains at Ford have come from a $250 million investment in new technologies and process improvements over the past five years. But the company has also been demanding that its suppliers create more energy-efficient designs when building new machines or revamping existing ones. “We think our energy-efficiency efforts will swim upstream to the Tiers and their machinery suppliers,” says Bill Allemon, Ford's manager of energy efficiency.
Ford isn't alone. The mind-set shift that puts life cycle costs and energy efficiency above the initial purchase price is starting to percolate through the full spectrum of industries as more and more companies look at energy efficiency's return on investment potential and at the relationship — captured by that energy intensity metric — between energy use and productivity.
Putting energy efficiency in the context of these larger business goals bodes well for it as a design strategy that machine builders can take to their customers. Or as Dennis Sadlowski, president and CEO of Siemens Energy & Automation puts it, “The case for energy efficiency is increasingly being made in the engineering departments and board rooms, not on the factory floor.”