Eighteen wind turbines make an elegant statement along the roofline of Kettle Foods’ southern Wisconsin plant. The low-power installation was preferred over solar as an alternative energy source. Source: AeroVation Inc.

Financial meltdown trumped melting ice caps as a public concern this fall, with sustenance farming and wild game hunting threatening to replace processed food for millions of Americans. But assuming for a moment that social collapse won’t occur and food and beverage manufacturing will continue, the green revolution in building design and operation will continue.

Environmental awareness is easier to express with a new building, and a number of companies have reinforced their green credentials by securing LEED (Leadership in Energy and Environmental Design) certification from the US Green Building Council. Gatorade’s Blue Ridge, VA plant became the industry’s first gold-certified LEED project in April 2007 (see “Sustainability with attitude,” Food Engineering, October 2007), and a number of other plants have followed.

But green design is not limited to greenfield projects. Arguably the most ambitious project to date breaks ground later this year in the Arizona dessert, when Frito-Lay engineers begin installation of the first phase of the snack company’s Net Zero project. A membrane bio-reactor (MBR) that will filter 75-90% of incoming water for re-use should be operational by 2009’s third quarter. “What better place to recycle water than in the desert?” asks Al Halvorsen, F-L’s director of environmental sustainability.

A concerted effort to slash water, gas and electric inputs per unit of production began at Frito-Lay in 1999. By the end of 2007, water use was down 38%, gas 29% and electric 22%. That gave rise to more ambitious goals: 90% cuts in water and electric used and 80% in natural gas. Energy recapture and waste reduction techniques introduced to F-L’s 37 plants over the last nine years would be combined with leading-edge technologies in Casa Grande, AZ. The 28-year-old facility was selected after a system-wide review by the National Renewable Energy Laboratory.

An F-L pilot of MBR produced water that met EPA standards for cooking food. Byproducts will help feed an anaerobic digester producing methane for the plant’s boilers in Net Zero’s second phase. The MBR also will free 100 acres of adjacent land where wastewater currently is spread. About half of the space will be dedicated to the project’s third component: parabolic troughs that reflect the sun’s light and concentrate it to heat water to 500°F. The pressurized water will help create process steam.

The solar technology is an advance over the photovoltaic (PV) solar systems more typically deployed. MBR, on the other hand, is “not on the leading edge of technology,” Halvorsen says, and harvesting methane from anaerobic digesters is well established. “Taking and combining all three of these technologies is the engineering challenge,” he says.

Workers at Fiscalini Farms take delivery of a 12-cylinder CHP engine that will run on methane harvested from anaerobic digesters. Permitting almost derailed the project, which will push Fiscalini into the realm of energy suppliers. Source: Fiscalini Farms.

F-L staged an Earth Day ribbon cutting for a solar concentrator project in Modesto, CA. Two hundred miles to the south, Ausra Inc. unveiled its own solar array last month in Bakersfield. The Australian technology firm is blanketing 18 acres with an array it calls compact linear fresnel reflectors (CLFRs) to power a 5 KW turbine.

Focusing curved mirrors on a boiler tube is significantly more efficient than PV solar, maintains Erik Ellis, Ausra’s director of process steam sales. It also outperforms natural gas used to fire a boiler by heating the medium directly. Ellis estimates a 10-acre parcel of CLFR panels would yield 70,000mm BTUs in steam energy a year, enough to replace 90 trillion BTUs of natural gas needed to generate an equivalent amount of steam from a boiler.

Set-point temperatures are maintained by altering the amount of water circulated. Temperatures between 300° and 700°F are possible, Ellis says, and three quarters of a facility’s hot water and steam demand could be met by storing heated water in insulated tanks. That option won’t be used in Casa Grande, according to Halvorsen.

PV solar cells are fabricated from polysilicon ingots, the raw material of semiconductors. The connection prompted Cypress Semiconductor Corp. to form SunPower Corp., North America’s leading PV solar fabricator. The monocrystalline ingots the company uses for its most cost-effective panels are 18-19% efficient, according to Felix Aguayo, senior project development manager. More copper, steel and other materials can yield slightly higher efficiencies, but the premium price is hard to justify.  

SunPower is based in California, the nation’s leader in solar energy. Aguayo works in Trenton, NJ, the number two solar state. The sun never seems to smile on Newark, but state regulators have smiled on solar with generous subsidies for panel installations. New Jersey wants solar to meet 2.1% of electric demand by 2021, says Aguayo.

Those subsidies should help Advanced Food Systems Inc. recover the cost of 2,500 solar panels in about five years. The array covers 35,000 sq. ft. of the Somerset, NJ firm’s roof, a placement that would not be possible with heavier CLFR panels. The system peaks at 500 kW, meeting most of the plant’s electric demand during the summer and about half its annual need, Operations Manager Bob Lijana says. On weekends, the panels feed electricity into the grid.

“Green isn’t a word we’ve used to describe the company,” says Lijana, “but we’ve designed our business around it.” T5 halide lighting cut electric consumption in half, or about 90,000 kW hours a year. Phased in equipment upgrades include premium motors on blenders and high-efficiency compressors. Extra wide aisles in the warehouse increase worker safety and minimize drivers jockeying a lift-truck fleet that is being converted to AC power from DC and propane.

AFS’s initiatives have caught the attention of customers, including a global food firm that wants to tout AFS as a “sustainable green supplier.” Employees also appreciate the effort. “They realize there’s more money for their profit sharing when we cut costs, and they appreciate that,” Lijana says, “and, more than I imagined, they’re proud of it.”

Fans blow outside air through a film of water in Bessamaire’s evaporative cooling system. Source: Bessamaire.

Earth, wind and freezer

Solar was a logical fit for F-L’s Sunbelt plant, though Halvorsen says the company wouldn’t consider it for a “frostbelt” deployment in Beloit, WI. Neither would natural chip manufacturer Kettle Foods, though for different reasons. “Solar panels require a lot of energy to make,” observes Jim Green, ambassador of the Salem, OR-based firm. “There’s a long carbon footprint.”

Kettle became the second gold-certified LEED food plant when it completed its Beloit, WI facility last year. Well-tuned, high-efficiency burners on custom-built batch fryers are a reflection of the firm’s serious approach to conservation, but LEED is more about style points. The plant’s 18 wind turbines are more symbolic gestures than serious energy sources, though the southern Wisconsin prairie is a good fit for localized wind turbines, according to Paul Glenney, director of the clean energy technology center at AeroVironment Inc. “Siting is the most critical part of turbine effectiveness,” Glenney says, and buildings five times longer than their height are ideal for maximizing wind acceleration.

Kettle installed the Northwest’s then-largest solar array in 2003 in Oregon. Generous subsidies dropped net cost 90%. Even so, the investment was not recouped for five years. Technical improvements provide a faster ROI on today’s PV panels; likewise, wind turbines are improving. When the Beloit units started up, each generated a modest 400 watts. Monrovia, CA-based AeroVironment technicians recently upgraded them to 1,000 watts.

“Ultimately, wind power offers more potential for wide-scale electrical production than solar,” Green believes. “Of all the things we’ve done, we get the most questions about those turbines.” BMW Design Works collaborated on the turbines, which have garnered several design awards, Glenney says.

Building a plant in the Midwest lopped 2,000 miles off transportation for Kettle’s chips, shrinking its carbon footprint by more than 3 million pounds of CO2 emissions a year. California-based Contessa Premium Foods will almost match that figure with better insulation and advanced refrigeration at its 115,000-sq.-ft. frozen seafood facility, a gold-certified LEED facility that opened in January. US food manufacturers generate 105 million tons of carbon dioxide emissions a year, the company claims. Refrigeration is a major contributor, and Contessa poured much of the building’s $6 million in added cost into advanced refrigeration.

The centerpiece is a heat recovery system built around the plant’s compressors. Superheated ammonia gas is routed from the compressors to a heat exchanger, where it flows through tubes immersed in a water-filled shell. The heated water then feeds the boilers. A push is on to classify that kind of reclaimed thermal power as renewable energy, according to Kurt Liebendorfer, senior vice president at Stellar Inc. The classification not only would qualify heat recovery for tax credits, it would help qualify for carbon credit trading and help food companies meet impending energy-efficiency mandates, he says.

Many areas of food facilities are held at temperatures below 40°F, and cooling systems long have been an energy black hole. An alternative technology getting consideration is evaporative cooling, which draws outside air through water-soaked pads or a water mist to lower temperature. “Evaporative coolers will always lower a dry-bulb temperature,” says Jim Powell, vice president-sales engineering for Bessamaire, a Cleveland, OH manufacturer of evaporative cooling systems. Coupling desiccant equipment is advisable in food plants to avoid potential bacteria and mold issues.

Evaporative cooling works best in a dry climate, making it ideally suited for the Southwest, where most equipment manufacturers are clustered. Fans and small pumps power the system, and energy demand can be as little as one fourth of a comparable vapor-compression system.

Energy in the trenches

Methane recovery from anaerobic digesters offers tremendous potential for food companies, Liebendorfer believes, and the Jacksonville, FL A/E firm is evaluating which wastewater streams offer the greatest potential. Beer and cheese stand out as high-return applications. “Where green is more of a marketing tool, energy from biogas might not hold appeal,” allows Liebendorfer, “but for those who are serious about addressing energy costs, anaerobic digesters are worth considering.”

Calculating return makes methane recovery a nonstarter for engineers focused on the business of food production. To simplify matters, Stellar is engineering standardized power islands and appropriately sized methane-powered engines from Caterpillar to simplify ROI analysis. “A biogas to electricity system has definite payback opportunities and produces recoverable energy output,” he says. A turnkey system with fixed costs should facilitate go/no go decisions.

John Fiscalini is taking the methane-recovery plunge on his 530-acre Modesto, CA farm, where he manages a herd of 1,500 milking cows. More and more raw milk is being routed to his 88,000-sq.-ft. farmstead cheese plant, where he produces high-end cheddars. Biogas Energy Systems in Seattle is installing two 900,000-gallon concrete tanks, with room for a third tank. “In this instance, we’re solving two problems,” Biogas Engineer Brian Gannon explains, “replacing fossil fuel and removing stinky waste.”

The cows generate 60 tons of waste a day, with Sudan grass trimmings and cheese whey added to the mix. Hot water, steam and electric demand for both the paddock and the plant will only consume half the harvested heat and power, with the rest feeding back to the grid.

The project’s centerpiece is a 12.5-ton Guascor engine. The 1,054 HP V-12 CHP unit will drive a generator churning out 710 kW of electricity. Heat exchangers on the radiator and the exhaust pipe will process boiler feed water. The permitting process almost stopped the project in its tracks, however, and dramatized why it’s hard to be green.

Fiscalini had to go offshore for an engine because no domestic manufacturer could meet California’s air pollution standards. The local board had established a 9ppm limit on NOX emissions. The best that a modified Caterpillar engine running at nearby Joseph Gallo Farms could do was 200ppm. “The board wrote me that they didn’t care about greenhouse gas or global warming, they just care about NOX,” Fiscalini grouses. After long negotiations, the authorities agreed to permit the engine with the addition of an exhaust scrubber.

“Without grant money and potential revenue from selling carbon credits, my system would not be feasible,” Fiscalini reflects. “Even with credits, it’s going to be a long ROI.” But after a state agency fingered California dairies as major contributors of greenhouse gases, “a lot of dairies said, ‘We have to do something,’” he explains. Soft returns from responsible stewardship and the positive message to environmentally aware consumers will soothe some of the sting.

Many customers, both individuals and trading partners, want to work with manufacturers who make green a priority. Initiatives also generate tremendous employee enthusiasm. At the recent Green Manufacturing Conference in Rosemont, IL, Vice President-operations David Cox of Blue Coat Systems testified about the significant cost savings generated by “an employee base energized about doing anything to help the environment.

“Our CEO never struck me as someone who was environmental,” he confided. “As we hit each cost-cutting milestone, he realized we could turn this into a competitive advantage.”

Energy-efficient lighting and two-sided default settings on photocopiers are simple actions any business can undertake, and the cumulative savings can be significant. But before they can determine where they are going, organizations need to know where they are, and that’s a challenge in food. San Francisco’s Kennedy/Jenks Consulting recently created a comprehensive self-assessment document for winery water management on behalf of the Wine Institute. Discussions are underway with the California League of Food Processors to produce similar guidance for tomato growers, cheesemakers and other segments. Benchmarking of water use and the composition of waste streams is a necessary first step, points out Sharon Melmon, senior associate and scientist at Kennedy/Jenks. Benchmarks are product-dependent, and chemical analysis and other expensive research is necessary to establish them.

“Water shortages became very real this year in California,” notes Melmon. “Water supply is tight, and energy is tight. There are no simple solutions, but there is a process for changing practices.”

Even with the self-assessment tool, reviewing existing practices and selecting appropriate tactics for reducing energy use and waste are time-consuming tasks. Executing solutions requires more investment of time and treasure. The payback can be significant, however, and manufacturers are going to have to tackle these issues sooner or later. 

For more information:

Paul Glenney, AeroVironment Inc., 626-357-9983, glenney@avinc.com
Katherine Potter, Ausra Inc., 650-424-9300
James Powell, Bessamaire, 440-436-1200
Brian Gannon, Biogas Energy Systems,
815-301-3432, bgannon@biogas-energy.com
Sharon Melmon, Kennedy/Jenks Consultants,
Kurt Liebendorfer, Stellar Inc., 904-899-9343, kurt@stellar.net
Felix Aguayo, SunPower Corp., 609-964-8900

Big Foot or Little Feet?

Many tools for calculating a business’ carbon footprint are available, and the possibility of an ISO standard is under discussion. But without a point of comparison to companies engaged in similar activities, it is questionable how much value a greenhouse-gas calculation can deliver to a manufacturer.

Not so with an individual’s carbon footprint. True, the calculations are rough, but as an awareness-building exercise, the results can be eye-popping. “I’m a California guy: I drive a hybrid, eat organic and try to buy locally,” Operations Vice President David Cox of Blue Coat Systems told the Green Manufacturing Conference in suburban Chicago. Yet after entering information on his travel patterns, home utility use and waste generation at the Carbon Disclosure Project’s site, Cox learned he was contributing 19 metric tons of carbon a year-slightly below the national average but well above the 11 tons by Europeans and Japanese citizens and the 4-ton average for the world’s 6.7 billion human inhabitants.

Cox used a calculator at http://www.carbonfootprint.com/calculator.aspx. Similar results would have resulted from the US EPA’s calculator, http://www.epa.gov/climatechange/emissions/ind_calculator.html.

Four flights a year to Japan were the culprit in Cox’s greenhouse gluttony. Rather than self-flagellation, he and other employees in the firm’s green initiative used the discovery to push for a travel reduction policy, coupled with more video teleconferencing equipment at each location. The bottom-line savings will be significant.