Food Safety / Innovation

Indispensable Energy Audits

November 1, 2011
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Energy audits and management can increase the bottom line, but to be effective, the job is never done.

In this soy protein isolate facility, energy monitoring systems keep track of electrical and thermal energy used in the process. Source: Rockwell.

Failing to be a good steward of WAGES (an acronym for water, compressed air, gas, electricity and steam) not only wastes energy, it also eats into profits. Indeed, being green can help a processor stay alive in this era of increasing energy and utilities costs.

 “Our foresight is that [geographical] areas of low power cost and subsequent subsidies are a thing of the past,” says Alex Daneman, president and CEO of Hench Control, a provider of energy management and industrial refrigeration systems.

Consequently, processors are reviewing their energy profiles because energy is no longer cheap no matter where it’s purchased, and it’s becoming a bigger part of production costs, according to Robert Gates, GE Intelligent Platforms global technical manager.

Customer expectations also play a role in the decision to go green. “The real drivers for energy conservation are coming from consumers and big box retailers,” says Gates. “Both see energy conservation as the right thing to do for the environment and the bottom line.”

According to Daneman, processors should consider three important points as they look for ways to audit energy usage and decrease energy costs:

1. Monitoring energy usage alone does not solve the problem.

2. Making the right adjustments after monitoring is crucial to lowering energy costs.

3. The energy audit/management process is not simple, nor is it a one-time occurrence.

A new model is also available for processors to use to audit energy usage within their plants, says Bill Schiel, director of business development at Invensys Operations Management and US delegate to the ISO 50001 Standards Committee. The June 2011 ISO 50001 Specification treats energy audits/management much like the ISO 9001 quality standard. “This is a management system-the same as a quality system. You develop a policy and define actions, metrics and improvements, and then do checks. It’s a ‘plan-do-check’ cycle for continuous improvement,” says Schiel.

The standard is now available as a template. With it, processors can take a more systematic, top-down approach to defining and reaching a goal, for example, to reduce energy usage by 15 percent over five years, according to Schiel. “This is an auditable process where an ISO certification can be obtained.”

While the new ISO standard provides a good template for energy audits, many processors that have been doing energy audits for some time already follow the same system. Steven Hawkins, Stellar’s director of automation, breaks it down into five steps: assessment (establish an energy usage baseline and determine goals for energy reduction), diagnostics and estimates (define the scope and estimate ROI), corrective action (engineer and install a system to monitor energy and utilities usage), monitoring (track energy usage and generate daily status reports) and ongoing maintenance (keep replacement parts readily available for the monitoring system).

“It is often said, ‘If you don’t measure it, you can’t manage it,’” says Paul Stiller, director of energy management for Summit Energy Services. “I would add measuring is not managing. I see food processors investing large sums of money in elaborate energy metering and reporting systems before they know what information is needed and why,” he adds. According to Stiller, it is essential to begin with the end in sight, design the management reports and clearly understand how they will be effectively used before investing in a metering system.

The continuous nature of energy audits, management and action cannot be over-emphasized. “We do not do short-term or one-time audits,” says Bill Holmes, principal, Holmes Energy LLC. “Our philosophy is: Instead of spending money on one-time audits, [clients should] spend the money to install energy-monitoring instrumentation. From then on, the client has a detailed, continuous and unbiased energy audit that shows when and where every energy dollar is spent within the facility.” Holmes adds that the instrumentation uncovers hidden opportunities for low-cost/no-cost savings with ROIs possible within weeks or months.

An initial audit tied to utility bills is essential, however, to determine what the ROI is likely to be on an energy management system. For example, “Our assessments combine operational and financial analysis,” says Bob Zak, general manager and president of Powerit Solutions. Assessments include analysis of electric bills and historical kW interval data; evaluation of opportunities to participate in demand response or other incentive programs; collection of detailed data about the facility’s main processes, largest electrical loads and the facility in general; and a site audit covering the entire facility and all processes, from receiving raw materials to final product shipping.

This is one of 15 cooling rooms where the Spara EMS (energy management system) from Powerit Solutions automates demand control and demand response (DR) at Four Star Fruit in Delano, CA. The system balances DR and energy efficiency with the operational requirements of the facility. The Spara system is set up to precool the room, offsetting all-at-once demands and at peak hours. Source: Powerit Solutions.

Obvious energy users

It would seem that many of the “low-hanging fruit,” or the obvious energy improvement opportunities have already been tackled by processors, but that isn’t necessarily so, according to many energy experts. “The most common energy-wasting problems in food and beverage facilities are inefficient lighting, lack of variable frequency drives (VFDs) on fans and pumps and steam process inefficiencies,” says Danielle Marquis, SmartWatt Energy corporate marketing manager.

While transitioning pumps and fans to VFDs usually represents a first step to saving energy, a good second step is to evaluate the means of control of older equipment, recommends Darryl Wernimont, POWER Engineers’ market specialist for food, beverage and consumer products. For example, the basic heat exchanger may perform as effectively as it did 20 years ago, however, the means of control, monitoring and verification probably need to be brought up to date.

Other savings opportunities, according to Marquis, could include adding night setback and other scheduling systems where appropriate, replacing/repairing steam traps, enhancing manufacturing processes (e.g., heat recovery from ovens or compressors) and replacing boilers and/or chillers, rooftop HVAC units, building and roof insulation and windows.

What’s on the roof is often out-of-sight and out-of-mind. “One large food production facility in a northern climate had abandoned older HVAC equipment in place,” relates Brad Heeres, principal and director of engineering services at GMB Architecture + Engineering. The units had steam heating coils. To prevent the heating coils from freezing during an extreme cold snap, steam valves were manually locked in a partially open position. While the solution was intended to be temporary, when the cold snap ended, the steam valves were forgotten. GMB’s engineers observed the condition in June while on site reviewing equipment related to another project. Plant management was alerted. The air handling units were more appropriately decommissioned and the steam coils disconnected, says Heeres.

Another slant on the rooftop air handler is the intentional disabling of the unit’s economizer, says Dan Homan, Rockwell CEM project manager. Homan’s seen lots of them. As a result, the equipment is using expensive mechanical cooling when free cooling from outside air is available. By repairing the economizers, upgrading the control system and using enthalpy comparison of return air and outside air to determine when switching to outside air is more efficient, processors can save energy by avoiding the use of mechanical cooling.

Psst ... It's not a secret

Speaking of cooling, some employees have been known to use compressed air for personal cooling, which is not only wasteful but potentially very dangerous, says Paul Humphreys, Atlas Copco vice president of communications and branding. While it’s easy to detect an air leak if you can hear it, it’s the inaudible leaks that really cost processors money. Humphreys says about 80 percent of air leaks detected in compressed air systems aren’t audible, and a single quarter-inch leak at 100psi costs more than $2,500 a year. Depending on pressure requirements and energy costs, by some accounts, this can escalate to as much as $8,000 a year per leak, says Humphreys. Piping systems more than five years old have shown leaks and need to be scrutinized.

Humphreys notes there are a couple of ways to reclaim energy from air systems. For example, air compressors generate heat that can be reclaimed to preheat water for boilers, warm areas of the plant floor or loading docks, or even aid in heating water for clean-up/washdown purposes.

In many plants, compressed air is maintained at a higher pressure than necessary. One facility manager, according to Humphreys, wanted to lower energy costs but avoid the ire of workers who complained about pressure drops. Beginning at 110psi, the manager dropped his system’s output by 1psi per day until he got a complaint. When he reached 99psi, someone complained, so he raised the pressure to 100psi and settled there with no complaints. According to Humphreys, every 2psig reduction cuts energy consumption by 1 percent.

“Flagrant energy waste often results from over-serving the need,” states Stiller. “For example, we recently encountered a food plant drying compressed air to -68°F dew point. This increased the cost of air by 30 percent (about $145,000 annually).” The client had installed special desiccant dryers years ago to meet a need that no longer existed.

Top: Mariah’s meat packing plant’s daily electric consumption consisted mostly of refrigeration (66 percent). Bottom: Because of defective automatic defrost valves in the refrigeration equipment, the system ran continuously, chalking up a tremendous false load placed on the power grid and costing an exorbitant sum. Source: Opto 22.

Not-so-obvious energy users

Hidden energy wasters are frequently found in efforts to solve other problems, says Heeres. In one case, an uninsulated plate-coil heat exchanger was the suspected cause of an overheated room. A review of the entire system revealed that direct discharge of steam to the room from a condensate receiver overflow line discharging to a trench drain in the space was the primary culprit. This led to the review of the operation of other condensate receivers in the facility. Action taken resulted in the addition of condensate coolers used to preheat the product and improvements in the condensate venting and overflow system-all of which provided an under-three-year payback, while improving the operation of the plant condensate return system, reducing boiler make-up water requirements and fixing the problem of the overheated space.

“Steam traps are a hidden energy waster-most customers are surprised to learn that there are incentives available to repair or replace steam traps, one of the most maintenance-intensive mechanical components of a facility,” says Bryan Genevick, SmartWatt Energy project development engineer. “A major grocery chain was surprised to learn that we could take over the replacement of hundreds of steam traps per month-and that its utility provided incentives for us to do so. We have also been able to reduce the need to use a chiller to cool 85°F water in parts of customers’ processes by implementing heat transfer to use this hot water to heat their warehouse.”

Keep your cool!

While steam, of course, is an important utility, “chilled media” is an energy-based utility that Schiel thinks should be added to the WAGES list-especially in a food plant where chilling is as important as heating or cooking. This concept of cool, sending a refrigerant around a plant to be used like any other utility, has to be created with other energy sources, primarily electricity.

One of Zak’s processor clients used to run its cooling systems continuously, including the fans. After an energy audit, which found the problem, and the implementation of Powerit’s energy management system, the processor’s systems are automatically turned off or down when a threshold temperature is reached, and the fans are slowed with VFDs or cycled off to prevent warming the space from the heat generated by the fan motors when they’re not needed. Peak demand and use reductions resulted in 13 percent lower costs.

At an older Mariah meat packing plant, the refrigeration system accounted for two-thirds of the plant’s total electric consumption, says Arun Sinha, Opto 22 director of business development. This was discovered after adding Opto hardware and Holmes’s AutoPilot energy information system to track the plant’s energy usage. The plant’s existing refrigeration equipment should have had more than twice the capacity to do the job. Yet, electric bills were exceedingly high.

“Knowing the utility costs associated with specific systems and areas within our plant helped us to determine that it was no longer competitive in our industry,” says Mariah’s General Manager Joe Brands. “When the data showed that the utility costs associated with parts of our operation were more than twice what they would be at one of our new plants, the need for major changes was clear.”

The problem was traced to the cooling coils in the freezers, which had their own automatic defrosting system. Periodically, hot refrigerant gas was blown through the cold coils to prevent ice buildup. Unfortunately, the old automatic valves that regulated the defrosting process had stopped working in a partially open position and continuously allowed hot gas to warm the coils, requiring the refrigeration system to run almost continually.

The processor had budgeted $100,000 for new transformers plus tens of thousands more to add refrigeration capacity until the monitoring system honed in on the problem. Once the valves were repaired, the refrigeration system got a big break, and so did the processor by cutting its electric usage by 600 KWhr per day, an annual savings of $250,000.

Decreased water usage saves energy

Processors that use water as their primary ingredient know something others may not consider until an audit is done. That is, decreasing water usage provides several benefits, according to Schiel. “There are companies like Anheuser-Busch that attack their water problem first-because it’s going to help fix energy problems. Think of it this way,” says Sheil. “If we can reduce the water intensity of our operation, we don’t have to buy as much water. [ If we don’t buy the water], we don’t have to clean it or preprocess it. We don’t have to heat it; we don’t have to cool it. We don’t have to treat it or pay the waste costs.”

Matutano-PepsiCo Group, located in Spain set out to reduce its energy consumption and water usage, according to the ISO 14001 environmental quality standard. The snack food maker installed a Schneider energy management system consisting of 41 PM710 electrical power meters and 17 Endress+Hauser flowmeters to monitor water, plus other instrumentation to monitor gas, air and steam. It also installed Vijeo Citect supervisory software and Vijeo Historian to monitor the WAGES usage in the plant. Before the Schneider project was accepted, several other auditors offered their services, but none of them included water usage. Water usage at this facility included several complex circuits. With the instrumentation in place and the system providing details on WAGES usage, the processor has been able to cut water usage by 38 percent and expects to cut energy consumption 20 percent by 2015.

Monitoring WAGES during non-production times-like the weekend-can provide some unexpected results. According to Homan, one processor identified some unusually high water usage over the weekend, which was traced to an out-of-the-way hand valve that had been open for months-maybe even years. By turning that valve off, the processor saved thousands of gallons of water that had previously been dumping down the drain.

One of Gates’ clients discovered through monitoring energy consumption and utilities during both working and non-working hours that water leaks from the locker room faucets and showerheads contributed 10 percent to the plant’s water consumption.

Take the load off

The cost of peak demand service sometimes puts a heavy penalty on electric bills. When situations are known, the remedy is to add VFDs and soft motor starters and make sure large motors are not started at full load or simultaneously.

Once a motor control system has been installed and operational, “temporary alterations to resolve urgent operating issues,” as Stiller calls them, can be expensive in the long term. In one case, a processor took a series of 40hp pumps off variable speed control to stabilize pressure in a product header. That was in 1993; no one ever went back to determine the root cause of the problem. Stiller says adjustments were made to a PLC program and solenoid valve in 2010, restoring variable speed operation. Running on fixed speed for those 17 years increased operating cost by well over $100,000. “By the way, I support temporary alterations; they are essential to keep product flowing,” says Stiller. “The key is to follow up, understand the real problem and find the best long-term solution.”

One of Zak’s clients had an ingredient mixing process that randomly occurred during different shifts, usually when the operator felt like it. Unfortunately this process often occurred when other equipment was making demands and/or when energy was most expensive. The problem was fixed by implementing an energy management system (Spara EMS) that tightly controlled whether the process could be started during these less-than-favorable peak power times when rates were the highest.

Smart technology and remote monitoring systems represent the next step in curbing energy costs, especially electrical energy, says to Tom Konicke, McKinstry operations manager, energy and facility services. Used reactively or proactively, these smart systems leverage and expand on technology already embedded within many facilities and equipment. McKinstry has the ability to monitor and control from a distance critical energy-using systems at clients’ facilities to obtain the best real-time rates.

The ultimate control for high-demand loads is smart grid, a system where utilities communicate directly with heavy, energy-consuming equipment in industrial applications and ultimately homes as well. “What we are starting to see occur in various regions, is that processors, via various smart grid integration options, will have options that will allow them to run certain processes during times of lower energy rates,” says Gary Khort, Iconics vice president of marketing.

First starting in buildings, then expanding into manufacturing operations, utilities are beginning to provide dynamic rate data (via smart grid protocols, public web services) and rate offers for the short term (next hour, next four hours, eight hours etc.), according to Khort. In addition to having the option to operate when energy is at a lower cost, processors will also be offered live feeds telling them how green the current energy supply is. They will be able to operate their selective processes and build inventory, when energy is most green, to improve their sustainability goals.

Today, an energy audit is not just good thing to do; it’s indispensable to operating efficiently. Many issues can be discovered and corrected automatically by an auditing/monitoring/control system. But, if you don’t make energy savings an inherent part of everyone’s work culture, you could find yourself slipping backward as employees opt for a quick fix to keep production running. Like a continuous improvement program for quality or food safety, energy has to be treated with the same importance.

For more information:
Alex Daneman, Hench Control, 510-741-8100,
Bill Schiel, Invensys Operations Management, 949-639-8731,
Bill Holmes, Holmes Energy LLC, 970-367-4225,
Bob Zak, Powerit Solutions, 206-467-3030,
Danielle Marquis, SmartWatt Energy, 518-406-5079,
Steven Hawkins, Stellar, 904-260-2900,
Darryl Wernimont, POWER Engineers, 208-288-6100,
Brad J. Heeres, GMB Architecture + Engineering, 616-796-0200,
Paul Humphreys, Atlas-Copco, 803-817-7479,
Dan Homan, Rockwell Automation, 414-382-2000,
Arun Sinha, Opto 22, 800-321-6786,
Paul H. Stiller, Summit Energy Services, 440-498-0100,
Robert Gates, GE Intelligent Platforms, 434-978-5000,
Tom Konicke, McKinstry, 503-331-0234,
Gary Khort, Iconics, 508-543-8600
Bryan Genevic, SmartWatt Energy, 518-406-5079,

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