Operations & Management
Energy Surge: The attraction of a sound energy management strategy
July 22, 2010 by Michelle Morra
Almost half. That’s how much of the world’s total delivered energy consumption is taken up by industry. And according to Natural Resources Canada, in 2007 this country’s manufacturing sector consumed an estimated 2,387 petajoules (PJ) of energy. That’s almost twice the energy consumed by all of the cars and light trucks in Canada.
Historically there have been no metrics associated with energy in industry, especially when there was plenty of business to go around and companies could afford waste. Ever since manufacturers started migrating far beyond North American borders, however, those remaining at home have had no choice but to be more effective, more efficient, leaner and greener.
Energy management has two parts: measuring how much energy is consumed, where and at what times; and then doing something about it. You can’t have one without the other, though some have tried.
"Some facilities put meters on almost all of their equipment, but then what?" says Tien-Khanh Ngo, an energy efficiency solution engineer with Schneider Electric Canada. "What they do with that data and how they manipulate it, many just don’t know."
Ngo has also seen the reverse scenario – not bothering to measure energy usage but going straight to a solution. Investing in a higher-efficiency furnace, for example, won’t help cut energy costs if the problem turns out to be drafty doors and windows. Measuring at the outset helps focus on solutions that match the problem.
Making changes in the plant to reduce energy costs isn’t all about capital expenditures. Nor does it have to happen all at once. Rather than replace every pump and motor, for example, facilities can instead commit to gradually adding high-efficiency technology as old equipment needs replacing, and eventually integrating "smarter" capabilities to their existing measurement tools.
First things first
So where should you start your energy management endeavour? While it’s important to take things slowly, there are certain steps that any plant, big or small, can implement right away:
• Commit to energy management as a corporate initiative. Making a commitment in writing to consuming and wasting less energy at all levels of the plant is a good first step. In his January, 2010 report entitled, Driving Value in Industrial Environments with Energy Management, Ivan Romanow, manager of business development at Gescan Automation, says that besides tracking energy consumption through utility bills, energy management is also about "how effective companies are when it comes to considering energy in operational decision making." Energy management must be an enterprise-wide corporate social responsibility initiative.
Romanow says that in some plants, up to 25 percent of total operational costs are energy-reliant. And that has business managers – eco-conscious or not – starting to pay attention.
• Get a formal, third-party energy audit. Experts recommend a formal energy audit every five years. The energy audit will certainly identify areas where you can immediately cut down on wasted energy.
• Embark on some general housekeeping. Take a look around your facility and consider these simple methods of reducing energy waste:
• Fix leaks in compressed air systems and HVAC ducts, windows and doors, etc., and have a consultant make sure your HVAC system is balanced. Also, if your production cycles allow it, consider turning off the HVAC on weekends or weeknights.
• Lubricate motors and conveyors, because smoother running machines have less friction, cause less downtime and use less energy.
• Identify areas in the facility where there is too much light, or unoccupied areas where the lights don’t need to be on.
• If safe to do so, there might also be opportunities to turn off or slow down dust collection and ventilation systems to match production rates. There is no need for dust collectors to run at full capacity while everyone is out for lunch.
• Measure energy use. "Visibility" has become a buzzword in energy management – because gone are the days of blindly consuming. Access to both real-time and historical energy data allows employees to understand the plant’s energy usage trends and how they compare with other facilities and industry standards.
"You can’t correct what you can’t visualize," says Romanow. A company might, for example, wait until a pump is broken before replacing it. But if the company had the metrics in place it might discover that the pump, while functioning, is faulty and wasting a lot of electricity.
"Wouldn’t it make more sense if I’m aware that it’s using twice as much energy as it needs to, and that it’s better to replace it now?" he says.
• Match supply with load demand. Manufacturers need to get over the "bigger is better" mentality. Ngo says it’s "the North American way" to buy the biggest motors and other equipment, perhaps with the logic that they will be safer or reduce downtime. The new, improved approach is to match the motor to the load.
It’s time to find alternatives to the traditional method of plugging something in, flicking a switch and running a machine full bore. Adopt a new mindset of always determining when and where you need more or less power. Rather than use a motor at full capacity, consider ramping it on slowly or backing it off once it’s rotating.
• Understand peak demands. Your utility bill is based not only on how much energy is consumed in the plant, but at which times. Understanding peak demands can save on those costs. "When people come into the plant in the morning and all turn on their machines at once that creates a big demand," says Ngo. "Accounting has to pay for that without knowing why it costs so much."
He recommends having a peak demands schedule that allows staff to stagger their equipment start-ups. "Team A would turn on their equipment, then after one to five minutes, Team B would turn on theirs, and so on," says Ngo. "Doing it in sequence allows you to avoid peak demand."
The same applies to things like treating ovens, which can be run at night instead of in the daytime when power costs more.
Acquire the right tools
Energy measurement devices come in the form of power monitoring systems, which measure both power use and power quality. They generally consist of meters to record data; software to gather, manage and display the data; and a way for the two to communicate. Advanced metering solutions verify the accuracy of utility bills with a comprehensive report, "including sags and surges, and the ability to measure power factor, harmonics and other parameters continuously," according to a white paper released in November 2009 by ARC Advisory Group.
To make energy consumption data visible and easily accessible, the SCADA (supervisory control and data acquisition) systems already installed in many facilities can function as part of the energy management infrastructure. A SCADA system can show energy consumption data from equipment such as pumps, conveyors, fans, compressors, boilers, co-generators, combined heat and power systems, and furnaces.
Besides measuring and displaying consumption, technology can help facilities control that consumption by automating and regulating equipment. "Smart" controls don’t require a major plant retrofit but can be integrated into technology the plant already uses.
"It’s not a new system they need to put in," says Ehab Rofaiel, product marketing manager at Siemens Canada Ltd. "It’s an expansion on the existing system." Rofaiel says customers are often pleasantly surprised to hear that they already have much of the necessary technology in place to get started. In companies of all sizes, it is often a revelation to operations managers that they already have the resources to make significant changes in their energy consumption and costs.
Motors, for instance, are often the most common source of energy inefficiency, especially in applications such as fans, conveyors, pumps, and compressors. Variable frequency drives (VFDs) can save energy on rotating equipment such as fans, pumps, conveyors and machine tool drives by controlling the speed of a motor.
According to the ARC white paper, "Replacing an old motor with a properly matched energy efficient motor and variable frequency drive (VFD) combination can sometimes provide an ROI measured in months."
Other smart systems that address inefficiencies in motor loads include soft starters and overload protectors, which a plant can integrate with its automation system.
Automation and smart technology can also regulate a facility’s HVAC system, increasing or reducing flow as needed. The same applies to lighting; a step beyond energy-efficient bulbs, automated lighting and control systems includes sensors that can, for example, automatically turn off the lights when they detect enough natural daylight coming through the windows.
Moving from low to high efficiency devices, says Ngo, can save a plant from five to 25 percent, depending on usage. Implementing smart control systems saves a further five to 15 percent. The next step is to continuously track energy use to ensure the facility maintains those savings.
Even before investing in energy management tools, having the right processes, procedures and practices and reducing waste from existing equipment will make a difference. When a plant goes leaner and greener, the planet wins, the company wins, the manufacturing sector wins. Yet Romanow says industry in general has yet to catch on.
"Should you be concerned?" he says, "Hey, if it’s 25 percent of your operating costs, if I was a financial guy I’d say, yes, you have to get a handle on it."
Michelle Morra is a freelance writer based in Toronto.