Powering down

Canadian Metalworking recently looked at green manufacturing, and had the fine example of Vic Store Fixtures in Victoriaville, QC, which had dropped its energy consumption by 57 per cent by, among other things, capturing heat from their furnaces and improving the ventilating and evacuating systems. But many, if not most manufacturers, have yet to deal with energy efficiency issues, and they are now in a tight spot as energy prices rise: the 2003 data from Industry Canada, which states that energy accounted for only 3 per cent of manufacturing costs in the metalworking sector, is likely conservative in context of recent energy price increases.

Build it right

Often plant set-ups don’t take energy conservation into consideration at all. Proper design can be a real boon, and support future innovation. Heat capture is perhaps the most obvious—some plants are designed to get rid of extraneous heat by sending it directly outside, whereas a properly designed plant can loop a lot of this energy back. Proper design can also reduce line leakage and make the plant more efficient in terms of such things as lighting, HVAC systems, and energy delivery.

“You should start thinking about energy use before you go into production,” says Tim P. Mitchell, B.Sc.ME, P.Eng., a Winnipeg-based industrial technology advisor with the Industrial Research Assistance Program (IRAP) and the National Research Council Canada (NRC). “This should happen at the engineering stage to reduce maintenance and make production more efficient throughout the life of the product.”

Conduct an energy audit

If you are already in production then the thing to do is to get an energy audit. Mitchell says that companies can learn a lot from previous efforts to promote lean manufacturing.

“We call it ‘lean to green’,” he says, “where we take those manufacturing tools used to improve productivity on the shop floor, and apply them to energy consumption throughout the whole plant. Lean is the value stream of the product, whereas green functions as an energy audit of a plant.”

Here the utilities companies can be your allies; many offer programs that include audits.

“In Manitoba the hydro interest is genuine,” says Miller. “They have 35 engineers on staff working with local manufacturers—each one has a specific expertise in energy reduction. And when they leave, they leave money on the table for the client. There is an absolute effect on the bottom line.”

For Miller, the sweet spot is when energy consumption hits $100,000 annually.

“That’s where you’re ripe to be looked at; you could save 30 per cent or even 50 per cent in consumption through these audits. There are consultants across

Canada who can do this.”

Typically an audit would involve spending a full day at the plant. The auditor would document current energy use and provide a report that contains specific recommendations to reduce consumption and increase savings—often the solution involves multiple small things, and not one or two “magic bullets”. Usually there is then a follow-up six months to a year later to gather data and determine what worked and what didn’t.

Key areas for energy conservation

Production

Saving energy consumption on the production side can include using inverter power sources for variable frequency drives (VFDs); energy can be saved by

controlling the frequency of the electrical power supplied to machine tool drives. And on the output side variable speed drives can improve efficiency by matching speed to changing load requirements, while also allowing accurate and continuous process control over a wide range of speeds. As well, there can be considerable waste on the line that can be mediated somewhat by, for example, repairing leaks in air compressors. And in high friction environments, efficiencies that can increase accuracy and reduce wastage—such as using digital readouts—can also end up saving money on your power bill.

Non-production

Electricity used in plants for HVAC, lighting, or office equipment, can be surprisingly wasteful. Options include installing tankless water heaters and switching to energy efficient lighting. Tankless or ‘instantaneous’ water heaters heat water only when needed by passing it through a small heating unit; they run more efficiently , and there is no need for large storage water tanks. Common in Europe and Asia, and gaining some popularity in home use in North America, they are rarely found in industrial settings. With regard to lighting, the obvious choice is to replace old T12 fluorescent tube lighting with more efficient T8 technology. This can make a big difference, reducing lighting energy costs by up about 35 per cent—that’s an 18 month payback. And the savings last: T8 lamps are rated at 18,000 to 30,000 hours.

Infrastructure

Managers of older plants that undergo energy audits are often shocked at how inefficient their electronics infrastructure is. Examples include transformers, old wiring, boxes, fuses, switches and miscellaneous hardware and instrumentation. Obviously, there are costs involved in upgrading infrastructure, but this is one area where the audit is crucial, as it can calculate an ROI so you know exactly where you stand, and can feel confident in making the investments—or not.

Conversion

An audit can determine whether it is viable to convert emissions from specific processes into electricity to help power the plant. One high-profile example is Ford’s Oakville, ON, assembly plant, which will feature the largest installation of its “Fumes-to-Fuel” technology that converts waste energy from the paint shop for use in the plant.

Adopt a “green” philosophy. Energy conservation is, in fact, a factor in most environmental initiatives. For example, although recycling is often considered “green” because it takes less stress off of landfills, it also makes sense because it means less energy is put into an end product the second time around. “In any situation, recycling results in an overall reduction in your energy footprint,” says Bill Hunnicutt, vice president of global sales for BC-headquartered JER Envirotech International Corp. “It is definitely a cost saving, too; the material has already been created, and you don’t have to retool.” Miller agrees, “from an energy standpoint, anything that can be re-used or recycled, so much the better.” This also means exploring other materials, from alloys to composites and bioplastics.

Conclusion

Big manufacturers are certainly getting the picture: In 2006, Chrysler LLC’s North American facilities consumed 15 per cent less energy per vehicle produced than in 2002, and Ford has reduced its global operational energy use by 27 per cent overall since 2000. But in Canada the big story comes in smaller packages: small and medium enterprises (SMEs) represent 94 per cent of all Canadian businesses, 58 per cent of GDP, and 65 per cent of private sector employment. As a result, they comprise a significant proportion of the supply chain of large enterprises, and their collective impact on energy consumption is huge.

“I work with a lot of metal bashers,” says Miller, “and I want them to see the opportunities. We used to talk about ‘sustainable manufacturing’, and people equated that with the feds and regulations. But now environmentalism and the word ‘green’ have a better image. People know there are good reasons to do this.”CM

Tim Wilson is a freelance writer based in Peterborough, ON.