Sustainable Plant of the Year: Frito-Lay Casa Grande Plant Attains Near Net Zero
Efficiency was built into Frito-Lay’s Casa Grande plant a quarter-century ago, but the snack maker takes the facility’s energy- and water-conservation systems to a new level with near net zero.
Is it feasible for food or beverage production ever to be resource neutral, consuming no more gas, electricity, water and other utilities than what it generates itself?
Perhaps theoretically, but not as a practical matter. Still, placing sustainable manufacturing in the context of assuring resource availability so operational capabilities are maintained, regardless of external disruptions, is intriguing. What would a food plant with net-zero impact look like?
A close proximity sprawls across 283 acres of the Sonoran desert in Arizona. Part learning lab, part sustainability showcase, the Frito-Lay facility in Casa Grande is the focus of the snack food manufacturer’s ambitious goal of creating a blueprint for sustained production in a resource-strapped tomorrow. Most of the energy-generation and water-reclamation technology in Casa Grande can be found elsewhere in the Frito-Lay production network, but never before has such a comprehensive infrastructure been created. The result is a plant that pushes the limits of what is possible in energy and water self-sufficiency.
Selection of Casa Grande came after an assessment of Frito-Lay’s 37 US facilities by the US Department of Energy’s National Renewable Energy Laboratory. Abundant real estate, Sunbelt location and middle-of-the-pack production size figured in the choice, but the pick also acknowledged the facility’s pedigree. Built in 1984, Casa Grande was a showcase of energy conservation for its day. Its systems and technologies earned it Food Engineering’s designation as 1985 Plant of the Year.
Efficiency is relative, and the chip maker holds itself to a higher resource-management standard today. Until a year ago, process wastewater was land applied to former cropland on the plant’s property. With construction of a membrane bioreactor and a low pressure reverse osmosis (LPRO) system, the facility has an advanced filtration infrastructure that reclaims all but the sanitary stream, returning up to three quarters of the water coming into the plant for reuse. Total dissolved solids in the returned water are one-tenth the level of municipal water. A third of the crop acreage now supports a field of 18,000 photovoltaic panels, part of a solar array that can generate up to 5 megawatts (MW) of electricity, enough to replace half the power drawn from the electric grid.
Thousands of solar panels and dishes make a dramatic visual statement, but the star of Casa Grande’s bid for energy independence is a biomass boiler that can generate up to 60,000 lbs. of steam per hour, matching the output of a gas boiler that now serves as a backup. With the biomass boiler, which burns wood chips and pulp, gas demand is slashed to one fifth previous levels as a ratio of consumption to pounds of finished goods.
Energy independence and resource neutrality are the goals Frito-Lay engineers set out to accomplish four years ago. “In one meeting, Group Vice President of Productivity and Sustainability Dave Haft, asked, ‘What if we took the best renewable-energy components at our locations and landed them in one plant?’” recalls corporate engineer Al Halvorsen, senior director-environmental sustainability. “What would the plant of the future look like?” The idea sufficiently intrigued PepsiCo CEO Indra Nooyi to warrant a green light for what ultimately became near net zero, a modified label that acknowledges the real barriers of complete resource independence. Nonetheless, the savings achieved in Casa Grande far exceed PepsiCo’s corporate goals (20 percent cuts in electricity and water use over nine years, 25 percent reduction in fuel consumption) and provide a road map to maintaining production in a resource-strained future.
When the landfill-reduction initiative began in 2008, 14 percent of Casa Grande’s waste went to the dump, according to Material Manager Rigo Munoz. Volunteers drawn from all areas of the facility began analyzing the waste stream and identifying recycling and reuse opportunities. By springtime, waste had been whittled down to “one last stream” representing 0.5 percent, and in May, the plant began diverting it to a California incinerator for conversion to electricity.
An assault on production waste commenced soon after. Specialists in lean/Six Sigma, continuous improvement and other areas backed up workers from each shift and the six production lines who volunteered to identify procedural changes. At kick-off meetings, the greater than $1 million savings possible with each percentage point waste reduction was put in tangible terms-two Cadillac Escalades for a point savings on the SunChips line, for example.
“We can draw up changeover schedules and hand them out, but the experts are out there on the floor,” notes James Tidwell, 2nd shift corn team leader and one of 10 workers who were among the plant’s original hires in 1984. “We want them engaged and providing input.”
Volunteers enjoy bonuses when goals are met, and soft benefits accrue to all for altering behavior. Elevated solar panels form a canopy over the parking lot, shading employees’ vehicles from the desert sun while generating renewable electricity. A recycling vending machine that accepts cans and bottles provides credits workers can redeem for gifts or donate to a veterans organization.
Casa Grande also was the first Frito-Lay facility to achieve LEED gold certification for an existing building. Numerous improvements to the existing system were made, including installation of 186 solar tubes for natural lighting. T-12 fluorescents were upgraded to T8/T5 lighting technology; LED lighting is being evaluated.
The facility was expanded last year to 160,000 sq. ft. to accommodate Frito-Lay’s seventh SunChips line. SunChips’ eco-friendly positioning will get a boost when Casa Grande takes delivery of two electric delivery vehicles. According to Plant Director Jason Gray, recharging will be done directly from one of the photovoltaic arrays, closing the supply chain energy loop.
When the landfill-reduction initiative began in 2008, 14 percent of Casa Grande’s waste went to the dump, according to Material Manager Rigo Munoz. Volunteers drawn from all areas of the facility began analyzing the waste stream and identifying recycling and reuse opportunities. By springtime, waste had been whittled down to “one last stream” representing 0.5 percent, and in May, the plant began diverting it to a California incinerator for conversion to electricity.
An assault on production waste commenced soon after. Specialists in lean/Six Sigma, continuous improvement and other areas backed up workers from each shift and the six production lines who volunteered to identify procedural changes. At kick-off meetings, the greater than $1 million savings possible with each percentage point waste reduction was put in tangible terms-two Cadillac Escalades for a point savings on the SunChips line, for example.
“We can draw up changeover schedules and hand them out, but the experts are out there on the floor,” notes James Tidwell, 2nd shift corn team leader and one of 10 workers who were among the plant’s original hires in 1984. “We want them engaged and providing input.”
Volunteers enjoy bonuses when goals are met, and soft benefits accrue to all for altering behavior. Elevated solar panels form a canopy over the parking lot, shading employees’ vehicles from the desert sun while generating renewable electricity. A recycling vending machine that accepts cans and bottles provides credits workers can redeem for gifts or donate to a veterans organization.
Casa Grande also was the first Frito-Lay facility to achieve LEED gold certification for an existing building. Numerous improvements to the existing system were made, including installation of 186 solar tubes for natural lighting. T-12 fluorescents were upgraded to T8/T5 lighting technology; LED lighting is being evaluated.
The facility was expanded last year to 160,000 sq. ft. to accommodate Frito-Lay’s seventh SunChips line. SunChips’ eco-friendly positioning will get a boost when Casa Grande takes delivery of two electric delivery vehicles. According to Plant Director Jason Gray, recharging will be done directly from one of the photovoltaic arrays, closing the supply chain energy loop.
Production plays a minor role in food’s carbon footprint. Suppliers, copackers and other supply chain partners are strongly encouraged to participate in continuous improvement of sustainable practices. Sharing best practices helps all supply-chain partners reduce their resource consumption and encourages development of enabling technology.
For example, Frito-Lay redesigned the corn cook process for tortillas, leaving 40 percent of the water in the tanks for the next batch. The idea was embraced by Shearer’s Foods (Food Engineering’s Plant of the Year, April 2011), which was awarded LEED platinum status for its Massillon, OH facility. Shearer’s also commissioned a sealed-cavity oven using infrared ceramic burners from an F-L supplier that helped slash gas consumption 47 percent. Building on those advances, Frito-Lay engineers now are designing additional efficiencies into a specification for a new oven they expect will outperform the Shearer’s unit.
With 10 corporate engineers committed to energy management and regulatory compliance, Frito-Lay is able to upgrade standard systems. An example is an air-sweep system that suctions off rinse water from potato chips as they enter fryers. Reengineering the unit to vacuum off the water for reuse lowers the fryers’ thermal load because less moisture needs to be boiled off. With 25,000 lbs. of product going through a fryer every hour, the savings quickly add up.
Any facility below 33º latitude is ripe for solar-energy harvesting. The question in Casa Grande was scale. With 283 acres of land, the site has room to generate a surplus of electricity, “but when you put pencil to paper, that was not a wise business decision,” says Halvorsen. Instead, a variety of photovoltaic technologies and financing approaches were used, including a partnership with renewable-energy investors (see related story on page 42). Three distinct systems were built: panels mounted on single-axis mechanics to track east to west, three dual-axis tracking systems that align panels with the sun’s point in the sky and 10 units shaped like large satellite dishes and lined with parabolic mirrors that concentrate light and focus it on a Stirling engine that generates electricity from a piston powered by the expansion and contraction of helium.
Instead of 10, fabricator Infinia Corp. of Kennewick, WA envisioned a field of hundreds of dishes, but F-L engineers preferred starting small and developing a learning curve. “We love to push the envelope,” Halvorsen says, “but we have to balance the risk while maintaining a cutting edge.” The dishes will power the plant’s electric delivery vehicles. Appropriately, those trucks will distribute SunChips.
Long travel distances in the Southwest limit opportunities for electric vehicles, and experiments with hybrid vehicles have not fared well. But distribution accounts for a third of the company’s greenhouse gases, and better fuel efficiency is a priority. Fleet-wide performance more than doubled in three years to 18.5 mpg in 2010, with 25 mpg targeted by 2014. Technology and human behavior work in tandem: GPS devices in all 14,126 trucks ensure engines are turned off while drivers are making deliveries, and routes are plotted to reduce miles driven, a best practice Frito-Lay picked up from the EPA’s Smartway program.
Some alternative energy sources were rejected because of practical considerations. The BOD load from washing potatoes wouldn’t generate much methane, so anaerobic digesters were ruled out. The biomass boiler could have been outfitted with a condensing steam turbine to generate electricity from waste heat, but that would have required cooling tower water, which would undermine water-recovery gains. Creating an integrated system that minimized demand on all utilities was the goal.
From an economic perspective, reducing water consumption is difficult to justify. As a global manufacturer, Frito-Lay already operates in water-stressed regions, and with availability becoming a concern in areas in North America, managers reasoned now is the time to develop a water-recycling knowledge base. “When is the best time to figure out how to operate a plant with 70 percent less water?” Halvorsen asks rhetorically. “It’s not in a drought; it’s right now.”
A membrane bioreactor from GE with storage capacity of 1.2 million gallons was the first major installation in the net zero project, coming online in May 2010. According to GE, the reactor reclaims 648,000 gallons of water a day, a figure that fluctuates with production. The system enables the plant to reuse half the water it taps from the municipal waterworks.
Another new technology is the LPRO system downstream from the bioreactor. Project Engineer Sam Tajahmadi says fouling was an issue initially, but the installation of carbon filtration tanks as a pretreatment step helped increase reuse rates to 65 percent. Installation of larger, permanent tanks is expected to take reuse to 75 percent. The same technology, which operates at pressures below 200psi, is being applied at Frito-Lay’s plant in Tingalpa, Australia.
While corporate management never established a budget for net zero, “that didn’t mean an open checkbook,” Halvorsen emphasizes. “We had a 10-year record of energy-savings projects that drove dollars to the bottom line,” and net-zero investments were expected to generate a reasonable return. “With unlimited funds, I could take any plant off the grid,” he adds. “The question is, where is the balance between net zero and generating a return to the company?” Payback calculations assumed no increases in energy costs-a conservative approach with electricity, though the decline in natural gas costs highlights the uncertainty in projecting commodity prices.
Water comprises 80 percent of a potato’s mass. If that water could be captured and reused along with the exhaust’s heat, facilities like Casa Grande would become net water producers. Whether that becomes reality or remains science fiction, net zero puts Frito-Lay in the company of the US Army and engineers engaged in contingency planning for resource-stressed situations. The military regards net zero as a force multiplier by pursuing sustainable practices so that operations aren’t compromised in the event of external disruptions. The stakes may not be as high for a food plant, but a manufacturer’s future survival may hinge on the sustainable defenses put in place today.
For more information:
Todd Michaels, Solar Power Partners Inc., 415-259-6305, todd@solarpartners.com
Most of the 5MW solar-electric capacity in Casa Grande derives from two adjacent fields on the northern end of the property. Although the 18,000-plus panels require 36 acres, the facility’s sprawling site easily could have accommodated enough photovoltaic panels to match the plant’s entire electricity demand. Instead, they settled for an infrastructure that generates about 10 million kWh a year and further lowered the company’s financial exposure by striking a deal with Solar Power Partners Inc., San Francisco, to own and manage one of the northern fields.
Negotiating the 20-year agreement with Solar Power was a new experience for Frito-Lay, though it’s old hat for Solar Power, which has executed more than 60 similar projects and has another 30 in the pipeline, according to Todd Michaels, marketing director at Solar Power. Additional negotiations for power purchase involved Arizona Public Service Inc., the electric utility that also provided production-based incentives.
The renewable-energy sector is on the defensive, with momentum shifting to the oil industry and others intent on curbing growth in alternative fuels, concedes Michaels. “They see the opportunity to go for the kill,” he says. Nonetheless, “you can do deals without subsidies and still compete” on pricing and investment ROI. Solar Power continues to investigate proposals involving generation of at least 500 kW with companies that have excellent credit ratings, own their own facilities and have appropriate sites. In today’s environment, that often means locations in Arizona, New Mexico, Massachusetts, Hawaii, Puerto Rico and New York.
Albert DeCima pulls a sample of SunChips as they emerge from the fryer. Casa Grande became the seventh plant in the Frito-Lay network to produce the chips when the new line was completed last year. Source: Reed Rahn.
Ten parabolic mirrors concentrate sunlight and use the energy to power Stirling engines that generate electricity through the compression and expansion of helium gas. Source: Reed Rahn.
Perhaps theoretically, but not as a practical matter. Still, placing sustainable manufacturing in the context of assuring resource availability so operational capabilities are maintained, regardless of external disruptions, is intriguing. What would a food plant with net-zero impact look like?
A close proximity sprawls across 283 acres of the Sonoran desert in Arizona. Part learning lab, part sustainability showcase, the Frito-Lay facility in Casa Grande is the focus of the snack food manufacturer’s ambitious goal of creating a blueprint for sustained production in a resource-strapped tomorrow. Most of the energy-generation and water-reclamation technology in Casa Grande can be found elsewhere in the Frito-Lay production network, but never before has such a comprehensive infrastructure been created. The result is a plant that pushes the limits of what is possible in energy and water self-sufficiency.
Selection of Casa Grande came after an assessment of Frito-Lay’s 37 US facilities by the US Department of Energy’s National Renewable Energy Laboratory. Abundant real estate, Sunbelt location and middle-of-the-pack production size figured in the choice, but the pick also acknowledged the facility’s pedigree. Built in 1984, Casa Grande was a showcase of energy conservation for its day. Its systems and technologies earned it Food Engineering’s designation as 1985 Plant of the Year.
Efficiency is relative, and the chip maker holds itself to a higher resource-management standard today. Until a year ago, process wastewater was land applied to former cropland on the plant’s property. With construction of a membrane bioreactor and a low pressure reverse osmosis (LPRO) system, the facility has an advanced filtration infrastructure that reclaims all but the sanitary stream, returning up to three quarters of the water coming into the plant for reuse. Total dissolved solids in the returned water are one-tenth the level of municipal water. A third of the crop acreage now supports a field of 18,000 photovoltaic panels, part of a solar array that can generate up to 5 megawatts (MW) of electricity, enough to replace half the power drawn from the electric grid.
Thousands of solar panels and dishes make a dramatic visual statement, but the star of Casa Grande’s bid for energy independence is a biomass boiler that can generate up to 60,000 lbs. of steam per hour, matching the output of a gas boiler that now serves as a backup. With the biomass boiler, which burns wood chips and pulp, gas demand is slashed to one fifth previous levels as a ratio of consumption to pounds of finished goods.
Energy independence and resource neutrality are the goals Frito-Lay engineers set out to accomplish four years ago. “In one meeting, Group Vice President of Productivity and Sustainability Dave Haft, asked, ‘What if we took the best renewable-energy components at our locations and landed them in one plant?’” recalls corporate engineer Al Halvorsen, senior director-environmental sustainability. “What would the plant of the future look like?” The idea sufficiently intrigued PepsiCo CEO Indra Nooyi to warrant a green light for what ultimately became near net zero, a modified label that acknowledges the real barriers of complete resource independence. Nonetheless, the savings achieved in Casa Grande far exceed PepsiCo’s corporate goals (20 percent cuts in electricity and water use over nine years, 25 percent reduction in fuel consumption) and provide a road map to maintaining production in a resource-strained future.
Mark Duran Sr. is the only operator for nine SunChips packaging lines on his shift. The high-speed lines feature robotic case packers and palletizers. Source: Reed Rahn.
A sustainable foundation
Before any net-zero elements were put in place, Halvorsen’s team optimized the energy infrastructure, improving lighting and compressed-air efficiency and outfitting motors as small as 1hp with VFDs. “The most efficient energy is the energy you never use,” he notes, and front-end improvements meant less water to recycle and a smaller boiler and solar array to install. The groundwork also acknowledged that human behavior is at least as important as technology in manufacturing sustainability. Workers at Casa Grande are among the company’s pacesetters in reducing landfill waste and packaging and production waste below 1 percent.When the landfill-reduction initiative began in 2008, 14 percent of Casa Grande’s waste went to the dump, according to Material Manager Rigo Munoz. Volunteers drawn from all areas of the facility began analyzing the waste stream and identifying recycling and reuse opportunities. By springtime, waste had been whittled down to “one last stream” representing 0.5 percent, and in May, the plant began diverting it to a California incinerator for conversion to electricity.
An assault on production waste commenced soon after. Specialists in lean/Six Sigma, continuous improvement and other areas backed up workers from each shift and the six production lines who volunteered to identify procedural changes. At kick-off meetings, the greater than $1 million savings possible with each percentage point waste reduction was put in tangible terms-two Cadillac Escalades for a point savings on the SunChips line, for example.
“We can draw up changeover schedules and hand them out, but the experts are out there on the floor,” notes James Tidwell, 2nd shift corn team leader and one of 10 workers who were among the plant’s original hires in 1984. “We want them engaged and providing input.”
Volunteers enjoy bonuses when goals are met, and soft benefits accrue to all for altering behavior. Elevated solar panels form a canopy over the parking lot, shading employees’ vehicles from the desert sun while generating renewable electricity. A recycling vending machine that accepts cans and bottles provides credits workers can redeem for gifts or donate to a veterans organization.
Casa Grande also was the first Frito-Lay facility to achieve LEED gold certification for an existing building. Numerous improvements to the existing system were made, including installation of 186 solar tubes for natural lighting. T-12 fluorescents were upgraded to T8/T5 lighting technology; LED lighting is being evaluated.
The facility was expanded last year to 160,000 sq. ft. to accommodate Frito-Lay’s seventh SunChips line. SunChips’ eco-friendly positioning will get a boost when Casa Grande takes delivery of two electric delivery vehicles. According to Plant Director Jason Gray, recharging will be done directly from one of the photovoltaic arrays, closing the supply chain energy loop.
More than 18,000 solar panels blanket 36 acres of former crop land owned by Frito-Lay. The single-axis tracking system follows the arc of the sun and generates the bulk of the facility’s 5 megawatts of photovoltaic generating capacity. Source: Frito-Lay.
Partners in sustainability
Before any net-zero elements were put in place, Halvorsen’s team optimized the energy infrastructure, improving lighting and compressed-air efficiency and outfitting motors as small as 1hp with VFDs. “The most efficient energy is the energy you never use,” he notes, and front-end improvements meant less water to recycle and a smaller boiler and solar array to install. The groundwork also acknowledged that human behavior is at least as important as technology in manufacturing sustainability. Workers at Casa Grande are among the company’s pacesetters in reducing landfill waste and packaging and production waste below 1 percent.When the landfill-reduction initiative began in 2008, 14 percent of Casa Grande’s waste went to the dump, according to Material Manager Rigo Munoz. Volunteers drawn from all areas of the facility began analyzing the waste stream and identifying recycling and reuse opportunities. By springtime, waste had been whittled down to “one last stream” representing 0.5 percent, and in May, the plant began diverting it to a California incinerator for conversion to electricity.
An assault on production waste commenced soon after. Specialists in lean/Six Sigma, continuous improvement and other areas backed up workers from each shift and the six production lines who volunteered to identify procedural changes. At kick-off meetings, the greater than $1 million savings possible with each percentage point waste reduction was put in tangible terms-two Cadillac Escalades for a point savings on the SunChips line, for example.
“We can draw up changeover schedules and hand them out, but the experts are out there on the floor,” notes James Tidwell, 2nd shift corn team leader and one of 10 workers who were among the plant’s original hires in 1984. “We want them engaged and providing input.”
Volunteers enjoy bonuses when goals are met, and soft benefits accrue to all for altering behavior. Elevated solar panels form a canopy over the parking lot, shading employees’ vehicles from the desert sun while generating renewable electricity. A recycling vending machine that accepts cans and bottles provides credits workers can redeem for gifts or donate to a veterans organization.
Casa Grande also was the first Frito-Lay facility to achieve LEED gold certification for an existing building. Numerous improvements to the existing system were made, including installation of 186 solar tubes for natural lighting. T-12 fluorescents were upgraded to T8/T5 lighting technology; LED lighting is being evaluated.
The facility was expanded last year to 160,000 sq. ft. to accommodate Frito-Lay’s seventh SunChips line. SunChips’ eco-friendly positioning will get a boost when Casa Grande takes delivery of two electric delivery vehicles. According to Plant Director Jason Gray, recharging will be done directly from one of the photovoltaic arrays, closing the supply chain energy loop.
Considerably larger than a gas-fired unit, the plant’s biomass boiler generates up to 60,000 lbs. of steam an hour, the same as the boiler it replaces but using wood scraps and agricultural waste. Source: Frito-Lay.
For example, Frito-Lay redesigned the corn cook process for tortillas, leaving 40 percent of the water in the tanks for the next batch. The idea was embraced by Shearer’s Foods (Food Engineering’s Plant of the Year, April 2011), which was awarded LEED platinum status for its Massillon, OH facility. Shearer’s also commissioned a sealed-cavity oven using infrared ceramic burners from an F-L supplier that helped slash gas consumption 47 percent. Building on those advances, Frito-Lay engineers now are designing additional efficiencies into a specification for a new oven they expect will outperform the Shearer’s unit.
With 10 corporate engineers committed to energy management and regulatory compliance, Frito-Lay is able to upgrade standard systems. An example is an air-sweep system that suctions off rinse water from potato chips as they enter fryers. Reengineering the unit to vacuum off the water for reuse lowers the fryers’ thermal load because less moisture needs to be boiled off. With 25,000 lbs. of product going through a fryer every hour, the savings quickly add up.
Any facility below 33º latitude is ripe for solar-energy harvesting. The question in Casa Grande was scale. With 283 acres of land, the site has room to generate a surplus of electricity, “but when you put pencil to paper, that was not a wise business decision,” says Halvorsen. Instead, a variety of photovoltaic technologies and financing approaches were used, including a partnership with renewable-energy investors (see related story on page 42). Three distinct systems were built: panels mounted on single-axis mechanics to track east to west, three dual-axis tracking systems that align panels with the sun’s point in the sky and 10 units shaped like large satellite dishes and lined with parabolic mirrors that concentrate light and focus it on a Stirling engine that generates electricity from a piston powered by the expansion and contraction of helium.
Instead of 10, fabricator Infinia Corp. of Kennewick, WA envisioned a field of hundreds of dishes, but F-L engineers preferred starting small and developing a learning curve. “We love to push the envelope,” Halvorsen says, “but we have to balance the risk while maintaining a cutting edge.” The dishes will power the plant’s electric delivery vehicles. Appropriately, those trucks will distribute SunChips.
Long travel distances in the Southwest limit opportunities for electric vehicles, and experiments with hybrid vehicles have not fared well. But distribution accounts for a third of the company’s greenhouse gases, and better fuel efficiency is a priority. Fleet-wide performance more than doubled in three years to 18.5 mpg in 2010, with 25 mpg targeted by 2014. Technology and human behavior work in tandem: GPS devices in all 14,126 trucks ensure engines are turned off while drivers are making deliveries, and routes are plotted to reduce miles driven, a best practice Frito-Lay picked up from the EPA’s Smartway program.
Rigo Munoz places empty beverage containers into a vending machine that tracks his deposits and lets him redeem points for prizes or donations to a veterans assistance group. While the so-called Dream Machine is a plant expense, it does stimulate involvement in the zero-landfill initiative.
Drought dread
In selecting the most appropriate technology for the site, engineers “looked at the true impact of being a sustainable plant and not just bits and parts,” notes Gray. “We’re really two plants now: We have a chip plant, and we have a utilities plant.”Some alternative energy sources were rejected because of practical considerations. The BOD load from washing potatoes wouldn’t generate much methane, so anaerobic digesters were ruled out. The biomass boiler could have been outfitted with a condensing steam turbine to generate electricity from waste heat, but that would have required cooling tower water, which would undermine water-recovery gains. Creating an integrated system that minimized demand on all utilities was the goal.
From an economic perspective, reducing water consumption is difficult to justify. As a global manufacturer, Frito-Lay already operates in water-stressed regions, and with availability becoming a concern in areas in North America, managers reasoned now is the time to develop a water-recycling knowledge base. “When is the best time to figure out how to operate a plant with 70 percent less water?” Halvorsen asks rhetorically. “It’s not in a drought; it’s right now.”
A membrane bioreactor from GE with storage capacity of 1.2 million gallons was the first major installation in the net zero project, coming online in May 2010. According to GE, the reactor reclaims 648,000 gallons of water a day, a figure that fluctuates with production. The system enables the plant to reuse half the water it taps from the municipal waterworks.
Another new technology is the LPRO system downstream from the bioreactor. Project Engineer Sam Tajahmadi says fouling was an issue initially, but the installation of carbon filtration tanks as a pretreatment step helped increase reuse rates to 65 percent. Installation of larger, permanent tanks is expected to take reuse to 75 percent. The same technology, which operates at pressures below 200psi, is being applied at Frito-Lay’s plant in Tingalpa, Australia.
While corporate management never established a budget for net zero, “that didn’t mean an open checkbook,” Halvorsen emphasizes. “We had a 10-year record of energy-savings projects that drove dollars to the bottom line,” and net-zero investments were expected to generate a reasonable return. “With unlimited funds, I could take any plant off the grid,” he adds. “The question is, where is the balance between net zero and generating a return to the company?” Payback calculations assumed no increases in energy costs-a conservative approach with electricity, though the decline in natural gas costs highlights the uncertainty in projecting commodity prices.
Water comprises 80 percent of a potato’s mass. If that water could be captured and reused along with the exhaust’s heat, facilities like Casa Grande would become net water producers. Whether that becomes reality or remains science fiction, net zero puts Frito-Lay in the company of the US Army and engineers engaged in contingency planning for resource-stressed situations. The military regards net zero as a force multiplier by pursuing sustainable practices so that operations aren’t compromised in the event of external disruptions. The stakes may not be as high for a food plant, but a manufacturer’s future survival may hinge on the sustainable defenses put in place today.
For more information:
Todd Michaels, Solar Power Partners Inc., 415-259-6305, todd@solarpartners.com
Investors hedge the solar bet
Financial considerations have killed many engineering initiatives, and it could have produced a more modest solar-to-electric element in Frito-Lay’s sustainability project. The investment in photovoltaic solar panels received a big boost from a California renewable-energy company that matches industrial companies with strong credit ratings and the necessary space with investors interested in the solid risk-adjusted equity returns from renewable energy projects.Most of the 5MW solar-electric capacity in Casa Grande derives from two adjacent fields on the northern end of the property. Although the 18,000-plus panels require 36 acres, the facility’s sprawling site easily could have accommodated enough photovoltaic panels to match the plant’s entire electricity demand. Instead, they settled for an infrastructure that generates about 10 million kWh a year and further lowered the company’s financial exposure by striking a deal with Solar Power Partners Inc., San Francisco, to own and manage one of the northern fields.
Negotiating the 20-year agreement with Solar Power was a new experience for Frito-Lay, though it’s old hat for Solar Power, which has executed more than 60 similar projects and has another 30 in the pipeline, according to Todd Michaels, marketing director at Solar Power. Additional negotiations for power purchase involved Arizona Public Service Inc., the electric utility that also provided production-based incentives.
The renewable-energy sector is on the defensive, with momentum shifting to the oil industry and others intent on curbing growth in alternative fuels, concedes Michaels. “They see the opportunity to go for the kill,” he says. Nonetheless, “you can do deals without subsidies and still compete” on pricing and investment ROI. Solar Power continues to investigate proposals involving generation of at least 500 kW with companies that have excellent credit ratings, own their own facilities and have appropriate sites. In today’s environment, that often means locations in Arizona, New Mexico, Massachusetts, Hawaii, Puerto Rico and New York.
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