But one drawback, particularly for operations that run continuously 24 hours per day, is the need to stock and change out the lead-acid batteries required to keep the trucks running.
“Currently, electric trucks need up to three batteries to go through a 24-hour cycle, so you may have to change out the battery after every eight-hour shift,” says Mike Field, vice president of engineering at The Raymond Corp. (www.raymondcorp.com), a Greene, N.Y., supplier of electric-powered lift trucks and other material handling equipment. The 15 to 30 minutes typically required for the change can mean lost pallet moves. And because a battery requires roughly eight hours to charge and another eight hours to cool down after the charge, truck users are required to stock three batteries per vehicle, Field points out.
Help may be on the way, however, in the form of emerging hydrogen fuel cell technology. These cells work by combining hydrogen with oxygen in a way that produces electrical power through an electrochemical reaction whose only byproducts are heat and water.
A number of companies are developing fuel cell technology as a potential replacement for batteries in lift trucks and other industrial vehicles. Cellex Power Products Inc. (www.cellexpower.com), a fuel cell development company based in Vancouver, British Columbia, Canada, for one, is focusing on the industrial vehicle market. In late February, Cellex announced the successful completion of field trials using hydrogen fuel cell-powered rider pallet trucks supplied by Crown Equipment Corp. (www.crown.com),新不来梅,俄亥俄州,日产叉车软木p. (www.nissanforklift.com), based in Marengo, Ill.
Raymond has also been working for about two years with several suppliers of hydrogen fuel cells to evaluate the technology for use in its vehicles, says Field. “We’re doing in-house testing, and there have been proof-of-concept tests done with our trucks at customer sites.” The results to date are promising. “We’re still in the developmental stage with this, but the business scenarios that we’ve run look like there’s going to be a money savings with the fuel cells,” Field notes.
Fuel-cell powered lift trucks will initially make economic sense for use in “multiple-shift, high throughput distribution centers,” predicts Blair Lill, marketing manager at Cellex. “The customers would be the likes of the Krogers, Wal-Marts and Targets of the world,” he says. It is in these kinds of “7-by-24” facilities, operating seven days per week, 24 hours per day, where the benefits of fuel cells will initially be great enough to offset the still relatively high cost of the technology, Lill believes.
Raymond’s Field agrees. For 7-by-24 operations, fuel cell-powered vehicles will eliminate the need to spend 15 to 30 minutes changing out batteries on each vehicle every eight hours, he says. Instead, hydrogen refueling will require only five minutes per vehicle or less at the end of each shift. “Literally, you’re just sticking a charging spigot into the side of the cell, and you’re refilling a tank,” he explains.
Users will also avoid the cost of stocking and maintaining three batteries for each truck. And fuel cells will also improve vehicle performance, Field points out. Unlike batteries, which produce declining voltage levels as they discharge—resulting in slower lift truck movements as the shift progresses—fuel cell technology provides a steady level of power throughout the eight-hour work period. That should translate to improved productivity.
Before fuel cell-powered lift trucks are introduced to the market, additional work is needed aimed at cost reduction and fuel cell durability, says Lill, of Cellex. “Really, what’s holding us up from going to market right now is the reliability of the fuel cell, and the second thing would be the cost, which is still very high.” But for use in 7-by-24 operations, Lill predicts that the first commercially available fuel cell-powered lift trucks will appear in 2007.
场,燃料电池的可靠性和成本的情况相符of-ownership are the current primary concerns. “We won’t put anything on the market before it’s ready,” he notes. But based on the pace of development, as well as the interest level from major Raymond customers, a product launch of a fuel cell-powered truck within the next couple of years is “definitely a possibility,” Field allows.
Wes Iversen,wiversen@automationworld.com
