With energy prices rising, energy conservation is a must for distribution centers. A few warehouse modifications can mean big savings.

Distribution centers nationwide are scrimping on their energy usage, especially after last year’s high energy prices and California’s rolling blackouts. This year and next, conserving energy will become even more urgent as energy prices continue to rise and one of the most unstable energy markets in recent decades grips the country. Although this summer’s total electricity demand is not likely to exceed last year’s, the country’s long-term total energy consumption is expected to continue climbing at an average annual rate of 1.4%. Meanwhile, the growth of commercial and industrial energy consumption will be slightly steeper, says the Department of Energy.

At Southern Wine & Spirits, a California-based wholesaler and distributor of wines, spirits and beers, energy conservation used to consist solely of turning off some lights. But rolling blackouts and the astronomical energy bills that followed them have jarred the company, which operates four distribution facilities, into action. “Management began to realize that high energy costs were a real threat to the organization’s bottom line and if things did not change, business would suffer well into the foreseeable future,” says Don Laroche, operations manager. They first conducted an energy audit, relying on California-based Alamo Lighting to pinpoint areas for improvement and energy-cutting techniques. The audit identified the most promising areas—computer equipment, warehouse lighting and motors powering the conveyor systems.

As warehouses increasingly rely on technology, computers are turning into one of the greediest energy guzzlers. In fact, computers, office equipment and telecommunication devices will propel one of the biggest boosts in electrical demand at warehouses in the next few years, says the Department of Energy. To curtail their avaricious consumption, computers should be turned off when not in use and monitors set on hibernation mode. In fact, much of the electrical power used by computers is wasted since they are needlessly left on. Businesses should consider the latest technology, which has energy-saving functions. The newer computers’ ability to automatically switch to low-power mode when not in use may make them more durable since they will stay on this sleep mode, using only 15 watts or less, for a large amount of time. Companies can save as much as $52 annually on utility bills per computer by using equipment with the Energy Star label. Moreover, these newer models produce much less heat so businesses can also save on cooling. Finally, companies can assign more than one user to a terminal. Cutting down the total number of computers used will trim energy consumption. Furthermore, knowing that others need to use the terminal, warehouse workers will likely refrain from Web-surfing and writing personal e-mails.

Lighting can be responsible for as much as half of a warehouse’s electric bill. The initial audit at Southern Wine & Spirits found that some fully lit parts of the distribution center (DC) remained idle up to 60% of the time. Fortunately, lighting solutions abound, starting from the most basic approach. “In areas where lighting isn’t critical, removing one of four bulbs is an easy trick that will also save energy in a pinch,” says Laroche. Meanwhile, in places where high-intensity lighting is crucial, more sophisticated methods can be employed. “In work areas and places where lighting quality can’t be diminished, timers and infrared sensors can be utilized,” says Laroche. “In production areas, timers were set to turn the lights on 30 minutes before the shift began and (off) 30 minutes after the shift ended.”

Total facility lighting upgrades can lead to dramatic savings. Southern Wine installed new high-output hibays throughout its 300,000-square-foot facility. These new fixtures were a vast improvement from its old metal halide lights, consuming only half as many watts and even producing higher-quality lighting. The company credits the lighting retrofit with yearly kilowatt-hour savings of 22%. They also report lighting savings of 55% and expect simple project payback in less than three years. Other companies have similarly benefited. Toro Co., a Minnesota-based manufacturer of turf and landscape products, revamped the lighting fixtures at its worldwide parts distribution center in Wisconsin. The project resulted in annual energy savings of nearly $40,000. Bemis Inc., a packaging material manufacturer, recouped even more. The lighting upgrade at its manufacturing facility in Wisconsin saved the company just under $400,000 annually.

Electric motors can be responsible for up to 40% of a firm’s annual electric bill. These motors turn electricity into mechanical energy, driving conveyors, automated storage systems and other material handling equipment. Shutting off conveyors is a start since they are often left running all day at full speed without carrying anything. Installing sensors will prevent their wasteful usage. Fortunately, recent improvements in soft start motors and adjustable speed drives have made it easier for conveyor systems to come back up to speed. Soft start motors make the action of starting up less jarring, minimizing damage to the conveyor and the product being conveyed. Adjustable speed drives, on the other hand, let the conveyor run at low speeds when there is no product on a particular section. Furthermore, motors today are made from better materials and feature energy-efficient designs with less heating loss.

Energy efficiency can also be incorporated into the building’s design and construction. The 1.5-million-square-foot Gap/Old Navy distribution center in Fishkill, New York, is one example. Completed last year, the DC features roofing, interior lighting and an insulation system that conserve energy. The roof reflects sunlight, making the interior cooler. Because it takes more energy to cool a warehouse than to heat it, big energy savings have been reported in facilities featuring sun-reflecting panels, especially in southern states. The Gap/Old Navy DC also optimized the natural light streaming into the facility by placing windows high on the walls. In addition, they avoided the problems of roof-mounted windows, which often have broken seals that allow interior heating and leaking. The facility’s lighting also reflects its careful design, featuring high efficiency fixtures and lighting controls. Finally, its insulation system lessens heat loss through convection through the facility’s walls for winter energy savings. As energy prices skyrocket, building facilities with energy efficiency in mind offers the cheapest, most effective solution.

Finally, learning to bargain for better electricity rates is crucial for warehouses. Deregulation will make utility providers more willing to negotiate. Some will even buy back unused electricity, as mandated in certain states. In addition, businesses that have implemented energy-conserving initiatives and equipment can avail of discounts. Managers must keep abreast of all the programs in their state.

Source: A Bright Idea
Jim Whalen, Associate Editor
Warehousing Management, June 1, 2002
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