Less air and a higher cube are the changes that immediately come to Pete Rolandelli’s mind when contrasting his new grocery distribution center (DC) with the one it replaced in Elizabeth, N.J.
As vice president-logistics and warehousing at Keasbey, N.J.-based Wakefern Food Corp., Rolandelli oversees almost 3.8 million sq. ft. of warehouse space packed with fresh food, groceries and general merchandise bound for ShopRite stores in the Northeast. The Elizabeth DC came on line two years ago, a 525,000-sq.-ft. facility that replaced a 485,000-sq.-ft. building on the same land.
“If you’re a warehouse guy, it’s all about more room,” he observes. “I got more room.”
The building’s footprint is only marginally larger than its predecessor, but with 1.7 million cases in inventory, twice as much product is packed into it. A bigger cube accounts for much of the capacity improvement: three tiers of racking that was 18 ft. high gave way to five tiers stretching 36 ft. in height. There’s also less “air,” or empty space above each pallet slot.
“How you work with the vendors to rack a building properly is the key to optimizing the space,” Rolandelli believes.
Stacking pallets higher is a reflection of improvements in “high-lows,” the lift trucks that place and remove pallets as they move in and out of the DC. The trucks simply couldn’t extend 36 ft. with their payloads when the original warehouse was built.
Pressed about other advances, the long-time warehouseman allows that another operational improvement is recharging those high-lows. Gone is the battery room where operators had to swap out the large DC batteries that drive those high-lows. Instead, charging stations keep the trucks rolling and operators working productively rather than dealing with the potentially dangerous task of battery changing.
In fact, battery rooms are disappearing throughout the material handling industry. “There are still a lot of people who swap out batteries,” cautions Darrell Williams, sales director at Power Designers USA, Madison, Wis. That approach still constitutes about half of the recharging activity in industry, but it is steadily shrinking. Instead, opportunity charging and fast chargers are where industry is moving, with the former systems representing about 40 percent of all installations, according to Williams.
A fast charger can deliver all the power an operator needs during a break, but unless an operation is in 24/7 mode, the premium price is difficult to justify. “Cost has come down dramatically since fast charging was introduced in 1998,” he says and now stands at about $8,000 per station, or 40 percent of the cost 16 years ago. That’s still three times the cost of an opportunity charger, so unless charging time is critical, manufacturers and their distribution arms take a pass on fast charge.
Energy efficiency, on the other hand, is coveted by many, and suppliers like Power Designers are plowing their R&D efforts into those types of improvements. Charge cycle efficiency typically is around 85 percent, meaning 15 percent of the AC current being fed into the charger is not captured by the DC battery being charged. Suppliers are turning to power modules that can be turned on and off during the start and final stages of the charge cycle, when conversion costs are greatest, to make energy transfer more efficient.
According to Williams, Power Designers’ Revolution charger boosts efficiency to 90-92 percent. For a 36V/850 Ahr battery, that adds up to a savings of 1.5 Whr per charge cycle.
Industrial lead-acid batteries are expensive, and extending battery life is another R&D focus. High-frequency opportunity charging helps optimize the process by reducing heat and overcharging. Maintaining a 40-60 percent state of charge will postpone the need to buy a replacement battery. If the charge reaches 80 percent, gassing and shedding occurs, destroying the unit.
Bleeding edge technology
Many factors enter into the calculation of what type of charging system to use, reflects Rolandelli, including labor savings and the sustainability image a company wants to project. Hydrogen fuel cells would provide faster charging for Wakefern, but it wasn’t judged important enough to justify their premium cost.
On the other hand, sustainable production was a priority at Testa Produce. When the firm built a 91,000-sq.-ft. distribution center at the southern tip of the old Union Stockyards in Chicago’s Back of the Yards neighborhood, owner Peter Testa wanted to make a strong environmental statement. Fuel cell-powered lift trucks were part of the statement.
A third generation steward of the 102-year-old firm, Testa purchased a 5-acre brownfield site and set out to achieve LEED platinum status when it opened in 2011. Efficient water use was a priority, even though the property is barely a mile from Lake Michigan, one of the world’s premier repositories of fresh surface water. A 764,085-gal. retention pond was excavated to collect rainwater for low-impact landscaping needs. Rainwater on the roof is collected and filtered in a 5,000-gal. cistern that fills non-potable water needs.
The most dramatic statement is made by a 238-ft. high wind turbine that was a first for the city. The turbine generates 880 MWh of electricity a year, satisfying the LEED platinum requirement of 20 percent renewable energy.
The city’s building code did not allow for elevated wind turbines or the LED lighting fixtures installed in the building, and building inspectors initially ordered Testa to rip out the fixtures and replace them with fluorescents. Not to be deterred, he lobbied the city and helped amend the code to allow for both LED and tall turbines. “I don’t deal well with no,” Testa simply states.
The green initiative reflects his personal beliefs and business commitment, he says, but it also delivers positive economic returns. Although the building is almost three times the size of the old facility, electric bills are only a third higher. The effort has been well received by the firm’s foodservice customers, many of whom are top-tier chefs in a service area stretching north to Milwaukee and South to Champaign, Ill., 150 miles away. “We’re up against the giants, and we have to set ourselves apart,” he points out.
Charging stations for hydrogen fuel cells cost in the neighborhood of $500,000, a prohibitive cost for a mid-sized firm. A system for methanol fuel cells, on the other hand, could be had for $15,000, so Testa opted for that system, along with lift trucks that could accommodate the cells themselves. Oorja, an India-based technology firm, was the supplier.
The three-minute charge cycle was a boon initially, but problems soon surfaced. “They worked for the first three to five months, but condensation that resulted from moving from a cold zone to a warmer one caused the complicated electronics to short,” Testa reports. Forced to abandon the technology, he ordered Crown lift trucks and installed Workhorse charging stations, though he hopes to try more robust fuel cells at some point.
That day may not be too far off, suggests Fernando Corral, vice president of Plug Power Inc., Latham, N.Y. “It’s becoming more economical for medium-size fleets to show positive ROI,” he says, and suppliers like Plug Power are achieving critical mass to accelerate the trend.
When Plug Power supplied 220 Yale lift trucks and pallet movers to Central Grocers five years ago for a new 934,490-sq.-ft. refrigerated warehouse in Joliet, Ill., it collaborated with Air Products Inc. for the liquid-hydrogen storage system. Now it’s able to fabricate the cryogenic tanks that store hydrogen at 6500 psi itself. The gas dispensing system and fuel cells themselves have demonstrated their industrial hardiness sufficiently to prompt Central Grocers to renew its five-year lease for next-generation equipment.
Energy costs, hours of operation, labor costs and real estate values all play a role in what type of material handling equipment a company chooses to deploy. Other considerations also come into play, and technical advances are expanding the range of possibilities for food companies.