When it's time to charge up their forklifts at the end of a shift, most drivers either line up at a battery-changing room or head for a fastcharging station. But not the drivers at East Penn Manufacturing Co.'s Topton, Pa., distribution facility. There, lift-truck operators maneuver their vehicles into a small drive-in refueling room attached to the building. Once inside, the driver dismounts and closes the door. He removes a hose from a wallmounted dispenser, inserts it into the tank onboard the lift truck, and turns a dial on the dispenser. In less than one minute, the tank is filled and the truck is ready for another full shift, using power supplied by hydrogen fuel cells.
While the rest of the world awaits the day when hydrogen-powered cars speed silently along the nation's highways, a revolution is already quietly under way in North America's DCs. For several years now, fuel cell-powered lift trucks have been gliding around manufacturing and distribution facilities run by some of the world's best-known companies. Wal-Mart has conducted fuel cell forklift trials, as have Raymond Corp. and East Penn. At least one tester, GM Canada, is about to embark on its second pilot.
Industrial edge
Although they're still considered an experimental technology, hydrogen fuel cells are not really new. "It's a technology that's been around since 1839," says Bruce Townson, director of business development for Hydrogenics, a Canadian-based developer of fuel cells. "Not much was done with the technology, however, until the Apollo space missions. Then in the late 1980s and early 1990s, developers began looking at it for powering vehicles."
At first, developers set their sights on the markets with the biggest potential payoff: cars and trucks. But as difficulties emerged with establishing a fueling-station infrastructure, many shifted their attention to industrial markets. Compared to the automobile market, the industrial truck sector has at least one overwhelming advantage: It doesn't require a network of public fueling stations. Lift trucks typically operate within the confines of a DC, which enables easy and centralized refueling.
How do you use hydrogen to power a lift truck? One way is to place a fuel cell power pack where a battery would normally fit and connect it to the truck using the same terminals a battery would use. The power pack consists of a tank to store the hydrogen once it's dispensed into the vehicle, a stack of fuel cells to create electricity, and a power storage device, such as a battery. The fuel tank holds about 1.8 kilograms of hydrogen, which is enough to power the truck throughout a shift.
The fuel cell stack consists of layered combinations of bipolar plates and membrane electrode assemblies coated with a catalyst such as platinum. The stacks allow hydrogen to combine with oxygen from the air to create a chemical reaction, splitting the electrons and protons of the hydrogen. In simple terms, the result of the chemical reaction is an approximately 50/50 release of energy and heat. The energy is converted to electricity to power the vehicle. Additional energy is stored in a small battery that provides power when needed for peak loads and captures regenerative power from braking. The heat is dispersed using a cooling fan.
A single cell can only produce about 0.7 volts of electricity, which means it takes a significant number of cells stacked end to end (as with flashlight batteries) to power a conventional 36- or 48-volt lift truck. The size of the stack varies according to the truck's voltage requirements.
Developers have found a receptive audience among lift-truck users. Part of the appeal, of course, is fuel cells' reputation for cleanliness (the only byproducts are water and heat). But fuel cells also hold other attractions for lift-truck users—consistent power delivery, shorter fueling times, and reduced maintenance, among them.
East Penn was one of the companies eager to start testing the technology. It might seem odd that East Penn, which manufactures the well-known Deka brand battery along with a variety of battery accessories, would be among those in the forefront of fuel cell testing. But the company doesn't view hydrogen as a threat to its business. "We want customers to be able to pick the right solution out of our bag," says Jim Rubright, East Penn's vice president of motive power sales. "We don't see hydrogen replacing battery use in facilities as much as we see it complementing them."
East Penn began experimenting with hydrogen about a year ago. In conjunction with its partner, Nuvera, a Cambridge, Mass.-based fuel cell manufacturer, the company outfitted 10 lift trucks at the Topton facility with hydrogen fuel cells. The company also installed a storage tank and compressor outside the building, and built a small drive-in refueling room attached to a door of the DC to house the dispenser unit. The decision to locate the dispenser in a separate room that's merely attached to the main building allowed East Penn to get the system up and running quickly and meet fire code requirements.
Rubright says East Penn's experiments have yielded impressive results. To begin with, the fuel cells have led to significant reductions in refueling times. Replacing the hydrogen takes less than a minute, while the entire process of moving into and out of the dispensing area takes less than five minutes. The DC is saving on space as well. "The space needed for the actual dispensing unit is about 2 percent of that required for a changing room," he reports.
On top of that, there are the benefits of consistent power delivery, which drivers consider a big plus. "Our operators have also been pleased, as they do not experience the voltage lag that batteries have when they begin to wear down," says Rubright.
Take two!
Testers at GM Canada's plant in Oshawa, Ontario, have reported similar results. GM Canada began experimenting with hydrogen fuel cells in 2004, when it placed hydrogen units into two lift trucks at the Oshawa plant, where Chevrolets, Buicks, and Pontiacs are assembled. Workers at the facility immediately noticed that with fuel cells, there was no drop-off in power, reports Brad Cochrane, GM Canada's facilities area manager. "It really takes variation out of the system. We achieved consistent productivity throughout the workday."
The success of that test has led GM to conduct an even larger trial, which is set to begin during the third quarter of this year. In the upcoming test, which will also be conducted at the Oshawa plant, GM will use hydrogen fuel cells from Hydrogenics to power 19 Hyster counterbalanced lift trucks that are used to deliver incoming parts to assembly stations. While GM produced and stored the hydrogen needed for its first trial on site, company officials say GM has yet to work out the details for the testing's second phase.
GM hopes to use what it learns from the upcoming trial in its ongoing research into ways to use hydrogen to power the passenger cars produced at the plant. "In general, GM as a company wants to explore all of the green technologies available," says Cochrane. "This project is just one piece of the knowledge base that will be needed for hydrogen fuel cells to break through as a mainstream energy technology."
Labor-saving device?
Certainly, hydrogen's reputation as a "green" alternative will be one of its biggest selling points. Hydrogen burns much cleaner than internal combustion systems, making it an attractive option for companies seeking to cultivate an ecofriendly image.
But there's no denying that the other kind of green—the greenbacks companies invest in their vehicles—will play a role in their decisions as well. "There are environmental benefits to hydrogen fuel cells, but it clearly will come down to what makes economic sense," notes Steve Medwin, manager of advanced research for lift-truck manufacturer Raymond Corp.
When it comes to hydrogen, cost can be a showstopper. Although the cost of outfitting a vehicle with a fuel cell power pack is about half what it was two years ago, it still comes to about $40,000 per truck, or about 10 times the price of a conventional lead acid battery. On top of that, there's the expense of equipping a building with a hydrogen storage tank, compressor, and dispensing system, which together total another $100,000 or more.
Although the technology may never be affordable for one- and two-shift operations, fuel-cell proponents argue that high-volume facilities—like the Oshawa plant, which operates 24 hours a day, five days a week—can expect to save money. "The busier the warehouse, the more likely the economic profile for hydrogen fits," says Rubright of East Penn."Hydrogen equipment is not cheaper, but the benefits come in productivity and saving labor."
Medwin of Raymond agrees. "The way you justify hydrogen is on productivity," he says.Medwin explains that since a hydrogen cell can be refueled in less than five minutes, it saves a great deal of time compared to battery changing. "Twenty minutes per shift per vehicle to exchange a battery is a lot of lost productivity," he says. "They are not moving goods while they are changing batteries."
Do the math
But others say the economics just aren't there right now. "Any customer looking to improve operations and productivity needs to do the math," cautions Steven Gitlin, director of marketing strategy for AeroVironment, the maker of PosiCharge battery charging systems and other power technologies. "Given the nature of the costs and alternatives available, there are more beneficial solutions already out there."
Gitlin explains that aside from the costs of the fuel cell packages and infrastructure, there are basic limitations on how inexpensively hydrogen fuel can be created and a system operated. When you add up all the expenses, it currently costs four to five times more to operate a hydrogen system in a vehicle than it does to recharge lead acid batteries in the same vehicle, he says. Eventually, that may drop to about half, but the costs will still be considerable, he adds. "Your hydrogen bill will still be about 2.5 times more than your electric bill. Two-and-a-half times is just a fundamental limitation of fuel cells based on how practical you can make those conversions."
"It will be hard to switch from what works today," adds Cesar Jiminez of Toyota Lift Trucks. "It is definitely difficult to justify the investment costs. Just the infrastructure costs alone are astronomical."
Yet those costs haven't stopped Toyota—or Raymond, for that matter—from developing experimental trucks using hydrogen. In fact, both foresee a day when lift trucks will be built around a hydrogen power system, in contrast to the current hybrid system, which simply replaces a battery with a hydrogen fuel pack.
Many observers also believe that costs will drop as the technology advances and adoption becomes more widespread. Think of it this way, says East Penn's Rubright: "What did you pay for your last VCR as opposed to your first?"
Hydrogen may be the most common element in the universe, but fuel cell users still need to find a way to "harvest" that hydrogen and store it.
Right now, companies have two choices for obtaining hydrogen: They can contract with a commercial supplier or they can manufacture their own on site. For most companies, the decision is dictated by economics—the local cost of the natural gas and/or electricity required to manufacture hydrogen vs. the cost of having it delivered from the nearest production plant. Hydrogen typically runs about $10 to $12 per kilogram, though some high-volume purchasers may be able to find hydrogen for as little as $5 per kilogram.
Commercial suppliers deliver hydrogen in one of two ways. They either bring it in via tanker truck and transfer it to an on-site storage tank, or they deliver a tube trailer consisting of several long tubes filled with hydrogen in gaseous form. In the latter case, the driver simply unhooks the tube trailer from the tractor and leaves it at the customer's site, where it can be connected directly to the facility's system. When the trailer is empty, the supplier delivers another full tube trailer and takes back the empty unit.
Companies that decide to make their own hydrogen will need conversion equipment that operates on either natural gas or electricity. The converter removes hydrogen from the air for processing in a gaseous form.
Whether it's made on site or delivered, the hydrogen must be compressed to 5,000 to 7,000 pounds per square inch before it can be used. The fuel passes through a compressor that assures that the gas can be dispensed into the tank properly while occupying as little cubic volume as possible once delivered to the vehicle.
Most facilities use a small storage tank to hold the compressed hydrogen. The dispensing station then draws the hydrogen directly from the tank. The dispensing station is normally located inside the facility and, similar to a gasoline pump, consists of a rectangular regulator box mounted to a wall. A hose protrudes from the box for dispensing the hydrogen gas into the vehicle. As a safety precaution, companies usually position hydrogen sensors in the dispensing area to monitor for leaks.
In many municipalities, fire and safety codes for hydrogen use and storage have yet to be written. Nonetheless, companies contemplating the use of hydrogen fuel are advised to check with their local authorities as early in the planning stages as possible.
