Brainstorm: Energy Management
This feature originally ran in the July/August 2011 issue of Food Manufacturing.
The Food Manufacturing Brainstorm features industry experts sharing their perspectives on issues critical to the overall food industry marketplace. In this issue, we ask: What are some of the most overlooked energy management methods food manufacturers can employ to reduce their utility expenses?
Bob Zak, GM and President, Powerit Solutions North America
Most food plants aren’t controlling peak demand at all. This is usually because they have the misconception that demand control requires long periods of loading shedding. That’s not the case. Timed and managed correctly, peak demand control actions can be short, infrequent and money-saving. More importantly, they can provide important project ROI to drive installation of additional sensors and controls that can have great value to the operators.
Many food manufacturers also have the capacity to participate in demand response programs at some level. It’s worth revisiting what’s on offer regularly—the demand response landscape changes every six months. Programs that initially seemed too aggressive or did not pay out enough may be totally different now, and in many cases, the dollars they deliver will justify participation.
Manufacturers often don’t realize the benefits they can gain simply by giving their plant operators visibility into energy use. The “Prius effect” is real, and an engaged workforce can really make a difference. Give people information on how energy is being used, and it will affect their actions. This can be done with some simple metering and creative presentation (display screens, e-mails, reports, indicators, and so on).
My last bit of advice is: get help. There are so many programs and resources available now to help plants improve their carbon footprint and reduce their energy costs, it can be hard to sort out the pros and cons of each, figure out what will work for you, and determine who can really deliver. Start by consulting your trusted resources — savvy electrical contractors; systems integrators; industry-leading vendors; utility reps. Assistance is there for the asking. Take another look — the possibilities may surprise you.
Marc Eeckhaut, Executive Vice President, Sales and Marketing, Global Water Engineering
Waste water from industry is one of the planet’s hugely overlooked sources of environmentally friendly green energy.
Pacific Beverages — a joint venture by Coca-Cola Amatil and global brewer SABMiller — uses methane produced from its waste water processes to power a designated steam boiler to reduce its total energy consumption by about 15 percent. This equates to about 300,000 Mj a year.
Any factory with a biological waste stream or wastewater with high COD (Chemical Oxygen Demand) can easily use this model to generate energy — particularly food and beverage plants.
Green energy from wastewater does not always get as much attention as more common renewable energy sources, such as wind and solar energy, but it is a near inexhaustible way of replacing fossil fuels, saving money and generating carbon credits in the increasing number of countries where these apply.
David S. Young, Senior Project Manager, SSOE Group
Through SSOE Group’s experience providing sustainable design and energy consulting services to our clients, combined with the real world operations experience of our staff, we have been able to recognize some great opportunities for energy efficiency. The following cost saving measures have various pay-back periods or returns on investment (ROI) and are often overlooked by food manufacturers as a means to reduce utility expenses.
Heat Recovery — Customers can capture exhausted heat from manufacturing equipment or processes (such as ovens, retorts, or the hot product stream itself) and can install heat exchangers that can be used to condition space, preheat make-up air for ovens, warm ingredients prior to batching or preheat boiler make-up water. When the amount of heat recovery is adequate, absorption refrigeration can be implemented to provide space or process cooling. ROI varies based on the system but numerous projects have resulted in a two-year ROI.
Water Reclamation — For processes that use city or well water for cooling product, water usage and effluent can be drastically reduced by implementation of closed loop systems utilizing a chiller or cooling tower. Often, CIP (clean-in-place) systems provide an opportunity for water reclamation by capturing final rinse water and using it for initial rinse. Investments in filtration or even anaerobic digesters offer an opportunity for water reuse and conservation, with the added benefit of reduced wastewater flow. Once again the ROI on these systems vary with the process and volume, but savings coupled with being a good environmental steward often justifies the expenditures.
Retro Commissioning Study — Another great source of potential energy savings that is often overlooked is having a retro commissioning study performed on your facility. This is an audit of existing equipment which brings to light potential repairs and system balancing opportunities which will optimize efficiency and reduce losses. This is important since most equipment/facilities tend to lose efficiency over time; periodically re-evaluating the system parameters is recommended to verify all are operating at peak efficiency. This cost saving measure typically has a two-to-three year ROI.
Utility Incentives — Many electric and gas suppliers offer rebates and other incentives to reduce energy consumption. Switching to an interruptible gas supply for boilers and adding a back-up fuel, may present an attractive option.
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