Why bother with energy efficiency?
Control Design, January 19, 2017
“The end user is looking for energy-efficient machines, but these users are also looking to do more work with fewer machines as a means of saving energy,” says Mark Sobkow, vice president of manufacturing solutions, RedViking in Plymouth, Michigan. “We do a lot of projects that focus on adding flexibility so that one machine or cell can do the work of what was done by many machines or cells in the past. That might take the form of a multi-attribute inspection machine or incorporating onboard automation onto assembly-line AGVs by using inductive power transfer (Figure 1). These allow plants to do more work with fewer machines.”
It goes beyond more efficient use of machines, as well. “Plant managers’ responsibilities on energy efficiency extend into finding genuinely sustainable options,” says Sobkow. “As a result, we’re seeing demand increase significantly for battery-free assembly-line AGVs, since lithium ion and lead acid batteries are so potentially damaging to the environment.” RedViking has also seen a big increase in demand for powertrain test stands that use electrical energy regeneration, because they can recapture up to 80% of their power for reuse in testing.
“One might think that direct cost savings is the ultimate goal for an energy-efficiency plan,” says Sree Potluri, I/O application specialist at Beckhoff Automation. “While this is certainly a positive benefit, we often see our customers using it as a means of overall production optimization. By monitoring energy usage in machines, companies are also able to detect inefficiencies which can indicate that part of the process is in need of repair or improvement. For example, bearings in a motor may become worn and use excessive energy due to the added friction. This inefficiency can then be addressed during scheduled downtime, rather than getting hit with a costly breakdown that stops production without warning.”
The idea of energy efficiency has typically been focused on a plant’s highest energy usage—water, air and heat, explains Mike Wagner, global OEM segment leader for packaging, Rockwell Automation. “More recently, packaging equipment has become a target as energy information becomes more readily available,” he says. “However, monitoring energy usage or even reporting this information is not enough. End users are increasingly asking for a full energy-reduction plan for their machinery and equipment. Improving efficiency, reducing waste and shrinking machine footprints are all ways to improve energy efficiency.”