Energy efficiency yields high return on investment

In the current economic climate, manufacturers are being pushed to the limit to find sources of cost savings. At the same time, many companies have taken on new and aggressive sustainability initiatives in an effort to do their part for the environment. Finding sources of energy savings affords bakers an opportunity to meet both of these goals.

Energy savings can be achieved in many different ways, from lighting and other infrastructure improvements to implementation of capital equipment advances to minimizing energy use and waste wherever possible. As rising energy rates impact bakers' profitability, there is perhaps no better way to reduce operating costs than to investigate some of the possible solutions for savings.

“In most places in the United States, converting lighting, motors and repairing plant operations, such as compressed air systems, should return 30 to 50 percent of investment each year,” says Rich Vaillencourt, vice president of engineering, Lime Energy, Glendora, Calif.

And, reduced electricity and gas consumption translates into lower carbon emissions. “We believe the greenest form of energy is the energy that is saved,” Vaillencourt adds.

Facilities and process improvements

Basic building modifications provide a starting point for energy savings. These upgrades include reducing lighting in nonessential areas; reducing or eliminating water leaks throughout the facility; installing water conserving components in toilets and faucets; assuring piping is insulated where needed to avoid heat loss and on cold line piping; and reducing compressed air leaks in the plant, says Jim Diver, vice president of operations, Dunbar Systems Inc., Lemont, Ill.

“Another consideration is that basic process infrastructure improvements can increase productivity while reducing overall consumption,” Vaillencourt says. “New boilers can achieve up to 96 percent combustion efficiencies. New chillers can reduce cooling operating costs by as much as 50 percent. Right-sizing pumps, pipes, and other distribution systems can improve production and quality by matching energy requirements to the actual load. And, insulation is always a good thing.”

In regards to lighting, an audit can identify the types of light fixtures used, as well as opportunities where lights can be turned off, or triggered with a sensor in lower traffic areas, such as warehouse aisles, notes David Laybourn, director of marketing and sales, Lime Energy. In many cases, metal halide high bay lights, those typically found in production and warehouse areas, are being replaced with a multi-lamp fluorescent fixture with high-output lamps, and often with high-power ballasts. These lamps degrade by no more than 10 percent over their useful life versus the metal halide lamps, which degrade by more than 40 percent after 60 percent of their useful life, even though the energy use stays the same as a new lamp, Laybourn adds.

Fluorescent lamps also use about half the energy of the metal halide lamps, depending on the price of energy and hours used. A fluorescent retrofit can pay for itself within one to four years, Laybourn says.

Capital equipment design

Technological advances in equipment design are helping bakers save energy costs. Most mixers in wholesale bakeries use some type of cooling mechanism to achieve the most efficient transfer of heat from the dough to the mixer's cooling surface, notes Greg Balnoschan, director of engineering, The Peerless Group, Sidney, Ohio.

Peerless recently introduced a new bowl with increased strength and improved cooling efficiency. “We went through several iterations of FEA (Finite Element Analysis) for stress analysis to improve our bowl strength, reducing the stress in the bowl by 42 percent,” Balnoschan says. “We also went through several iterations of CFD (Computational Fluid Dynamics) for fluid flow analysis of the mixing bowl. We significantly improved the cooling efficiency of our bowl, reducing the pressure drop in the cooling channels by 40 percent. The improvements have resulted in a greatly reduced cooling system on time and the elimination of ice requirements.”

By controlling the ramp rate of the frequency and voltage in the motor of a mixer using variable frequency drive (VFD), the high in-rush current is eliminated. The chart on the left shows a very large energy spike at the beginning of the operating cycle. A similar curve is shown on the right using a VFD and inverter starter duty motor. The energy spike at the beginning of the mix cycle is gone. – Greg Balnoschan, director of engineering, The Peerless Group.

Regarding depositors, bakers typically use a piston type that is pneumatically driven and difficult to clean. Mass flow depositing, a patent pending technology, eliminates pistons or volumetric depositing, Balnoschan notes.

“There is a huge savings in energy by the reduction in air consumption. The new depositor also is clean in place, reducing the water and waste water by a factor of 10,” Balnoschan says. “For the bakeries that have to haul off their waste water, this savings is huge. The new depositor costs more than the typical piston depositor, but the payback, which is heavily based on reduced product giveaways is very short. Product giveaways are reduced by up to 90 percent.”

Energy savings also can be achieved via oven technology. For example, an Auto Bake oven uses thermal oil as a primary heat source instead of electricity or gas. “The thermal oil is efficiently heated in a remote boiler to a temperature of 550°F,” says Diver. “The oil is than pumped at low pressure of less than 15 psi to the remote oven pump skid. The pump skid diverts the oil to four temperature zones in the oven and to the washer if installed. The oil flows through platens in the oven distributing the heat evenly throughout resulting in an even bake of product from the beginning to the end of a production run. The oil, now reduced in temperature by 15°F to 20°F, is returned to the boiler where it is reheated to 550°F. Since the boiler is only required to reheat the oil, it saves energy that is normally exhausted to the atmosphere.”

Capital-intensive heat recovery equipment presents another possibility for bakers. This option can reportedly save bakers between 15 and 25 percent of the heat input in food production. A detailed analysis of a bakery would be requierd to assess the feasability of such a system. The energy savings can pay back the capital investment within three to four years, for an ROI of at least 25 percent, according to Lime Energy.

Monitoring energy use

Tracking energy use is not only a necessity, but one of the most basic places to begin when pursuing an energy savings program. The utility bill provides tracking capabilities via energy units in kilowatt-hours and in dollars. Establishing overall energy goals and per unit of production targets are important metrics for any operations facility, Vaillencourt notes.

“Reduced consumption of electricity and gas is easily converted to reduced carbon emissions, which is important to measure per unit of production,” Vaillencourt adds.

Galaxy Desserts, Richmond, Calif., enrolled in a program called SmartLights with Pacific Gas and Electric Co. last November. Now, all of Galaxy's freezers are monitored and controlled online. They cycle on and off when they reach a certain temperature. Energy trend charts track amperage and the percent time the compressors run in each separate freezer zone.

Paul Levitan, company co-founder, president and C.E.O., expected a 30 to 40 percent utility savings from the freezers throughout this year. Within four months, data from the program revealed energy use had dropped from an initial 110 amps to 70 amps on average, which is a 36 percent reduction.

Energy efficiency is a “proven, immediate, verifiable and economic solution that often has benefits beyond the simple payback,” says Daniel Parke, president, Lime Energy, as reported in Environmental Leader, May 21, 2009.

And, saving energy not only reduces greenhouse gas emissions, but improves a company's standing in the community and in the baking industry.

Energy efficiency retrofit savings for bakeries

Azteca Foods, Chicago

• First year ROI 35%
• Peak demand kW reduced by 53.3
• Projected to save more than $40,000 per year from reduced energy costs

Fresh Start Bakeries: Ontario, Calif.

• ROI 75%
• Reduced lighting expense up to 70%
• Energy utility rebate $16,505
• Average monthly savings $4,600
• Annual electric savings $57,434

Galasso's Bakery: Mira Loma, Calif.

• ROI 73%
• Energy utility rebate $12,403
• Average monthly savings $2,810
• Annual electric savings $33,728

Franz Bakery: Seattle, Wash.

• ROI 71%
• Annual electric savings $18,000
• Projected to save more than $40,000 per year from reduced energy costs