John Deere Green
By Bill Moore
John Deere is one of America's oldest manufacturers and one of its most respected brands. Its trademarked field green can be found on an extraordinarily wide range of products from the traditional farm tractor to home lawn care equipment, even under the hood of many of the nation's bright yellow school buses.
With few exceptions, most are powered by fossil fuels, including the school buses that use Deere's natural gas-fueled engine. One of those exceptions is the "Gator" work utility hauler, a commercial version of which is battery powered. But with the explosive growth of interest in hydrogen and fuel cells, Deere's E-Drive Group, headed by former Nebraskan, Bruce Wood, climbed on the bandwagon to explore the potential of what many feel will be the power plant of the future. Wood spent half-an-hour with EV World to talk about the promise of fuel cells and other alternative power technologies at Deere.
I really didn't expect to see Wood or his hydrogen-powered Gator at the California Fuel Cell Partnership during my February 2004 trip to Sacramento for a pair of hydrogen and fuel cell workshops put on by SAE. Part of the session included a field trip out to the West Sacramento facility where eight major car manufacturers are testing some 41 fuel cell vehicles. Yet, there was Wood and his John Deere-green Gator, fresh from a trip to Los Angeles where he demonstrated it to community leaders. While others waited patiently in line to drive one of the fuel cell cars, I opted to take the Gator for a spin, instead.
As we drove around to the front of the CaFCP, Wood's explained a little bit about the project, noting that the four-wheel electric steering took a bit of getting used to. It is remarkably responsive and I had to steer with care. Best of all, the vehicle was nearly silent, its fuel cell barely audible, and it produced no pollution. I took Wood's photo and promised to follow-up with him, so EV World readers could learn more. This interview is a fulfillment of that promise. You can listen to our telephone discussion by using the MP3 Player at the right or by downloading the MP3 file to your computer.
Wood began our discussion by explaining that his team designed the fuel cell Gator to demonstrate the potential uses of a vehicle powered by such a high quality, mobile electrical power source. Not only does it offer quiet, pollution-free operation, but it also gives operators a moveable power source for running a whole host of tools and applications; from electric power tools to powering up jet fighters.
The vehicle's remarkably agile steering is made possible by four electric motors, one at each wheel. Its "drive-by-wire" system enables the operator to switch from conventional steering where the rear wheels lock in place, while the front wheels turn; to "crab" steering that enables it to move sideways; to counter-steering that lets it turn in a very small radius. In addition, a second switch on the dash, directs all 20kW of fuel cell power to a rear-mounted power strip for plugging in electrical appliances and devices, features not found on the conventional gasoline-version.
The model I drove in Sacramento stores its hydrogen in a single 5,000 psi Dynetek carbon fiber tank with a capacity of 2.6 kilograms of hydrogen, enough to power the vehicle for between four and six hours in the typical duty cycle on a golf course, for example. Wood noted that hydrogen storage is an issue at present, and that he would prefer the vehicle be able to operate for more than eight hours. By contrast, the battery version E-Gator has an eight-hour duty cycle, but it takes significantly longer to recharge and its hauling and performance capabilities lag behind the gasoline version. This is why Wood and his team are so excited about the promise of fuel cells.
"We see with fuel cells on board, you don't have limitations," he commented. To address the hydrogen storage problem, he plans to use metal hydride storage similar to that offered by companies like ECD.
"Part of our objective in putting these demonstrators together is to show people that not only don't you have to make compromises, but you'll get value that you otherwise wouldn't get out of other vehicle forms," he said.
Wood believes that commercial applications of fuel cells in vehicles will start to appear within the next four to five years, very likely in off-road vehicles like the Gator. On a golf course, for example, hydrogen could be provided by way of electrolyzer or by gas deliver from a company like Air Products, though both ways are, for the moment, very expensive ways to get hydrogen. However, since most off-road vehicles typically are fueled at a central location, Wood sees the problem of hydrogen distribution as posing less of an obstacle than it does for on-road vehicles like cars and trucks.
Renewable hydrogen can be created from solar panels or a wind turbine that powers an electrolyzer. Dairy, feed lot and hog farmers could take manure and digest it into hydrogen, making what was once an environmental problem, a clean, renewable energy source.
John Deere's E-Drive team choose to use a 20kW Hydrogenics fuel cell because it was available in the power range they were looking for. Most PEM fuel cells in development are either too large -- in the 50-100kW range, or too small, under 10kW. Wood said that besides the 20kW unit I had the chance to drive, Deere is also creating an number of other vehicles that will use a 10kW Hydrogenic stack. He noted that the Canadian-based company is partly owned by GM and therefore has assess to some of the carmakers fuel cell technology. Another critical factor is cost; the smaller sizes are less costly to acquire and to integrate.
Speaking of costs, Wood acknowledged that until fuel cells become cost competitive with the internal combustion engine, his golf course customers, for example, aren't going to buy a fuel cell-powered Gator. He said that the IC engine in the current model costs from $175 to $200 per kilowatt, so that's the target fuel cells will have to shoot for. Yet, he's also confident that this will happen before the decade is out, with the caveat being that customers are also going to have to see the added value fuel cells can offer before they commit to buying them.
A very tangible example are mining operations. Wood said that a number of mine operators use Gators for various underground tasks. The cost of keeping the mine adequately ventilated is very high, so replacing an IC with a non-polluting fuel cell vehicle would help reduce some of the extra ventilation costs needed to remove the pollution from the gasoline engine. Wood said these operators recognize the added value found in the fuel cell version because it will help them reduce some of their very high operational costs.
Another promising application is as a multi-purpose vehicle on America's aircraft carriers. Wood told me that the model I drove has caught the eye of the US Navy who sees it as a way to replace three vehicles shipboard. The fuel cell Gator is powerful enough to act as an aircraft tug. It's electric power output can be converted to 400 Hertz to also provide ground power to the ship's fighter wings. And it can also be used as an ordinance carrier both on deck and below. The vehicle's three steering modes, including the ability to move sideways, is ideal for operations on the cramped hangar deck. Best of all, hydrogen is abundant on a nuclear aircraft carrier, so there would also be some fuel savings.
Wood believes that it is unexpected niches like these that will be discovered and exploited long before the economics justify the migration to fuel cells in on-road vehicles. But this will also give companies the opportunity to learn and improve their products.
Diesels Beyond Tier Two
While fuel cells may well find their way into these important niches, one place you will not see them anytime soon will be in the one product John Deere is most famous for; it's farm tractors, which is somewhat surprising because the very first known application of a fuel cell in a vehicle was an experimental Allis Chalmers farm tractor in the mid-to-late 50s.
Why? Because its very difficult to beat the efficiency of a diesel engine in a farm application, Wood stated. So, instead, the company is devoting resources to make its current engines more efficient in order to meet increasingly stringent EPA Tier 3 and Tier 4 emission guidelines, which begin to gradually take effect in about three years. Some of this research includes diesel-electric hybrid configurations, using natural gas in specially-modified school bus engines, and experimentation with various blends of hydrogen and natural gas called hythane, as well as biodiesel.
In terms of hybridization, the first steps are to convert mechanical accessories that create parasitic loads on the diesel engine to electrical devices powered by batteries, ultra-capacitors or just bigger, more efficient generators. Wood said this would reduce engine emissions somewhat; while further hybridization would allow for a smaller engine, reducing emissions even more. A fuel cell APU might find its way eventually into the tractor to power the auxillary systems, but it won't provide motive power, Wood contends.
It's his view that hybrid technology makes the most sense in vehicles that do a lot of starting and stopping where the vehicle's kinetic energy can be captured and reused for relaunch, a power consumption regime completely different from a farm tractor. Here he sees transit buses and waste disposal trucks being good candidates. Deere is also exploring the use of hybrid systems in front-end loaders that are typically used in construction where there's lots of lifting and lowering, moving back and forth.
"This is a very different kind of tractor," he stated. "The basic tractor you see going out across a field [plowing] and cultivating, that will be the last one you see a hybrid in, and frankly, the last one you'll see a fuel cell in."
Instead, Deere sees a time when farmers will grow their own fuels, perhaps creating a hydrogen-biodiesel or natural gas (methane)-hydrogen blend on which to run his diesel farm tractor and combine. While there are limits, Wood acknowledged, he's told that it is possible to run a blend of 30 percent hydrogen and 70 percent compressed natural gas in a diesel engine with very little modification.
In fact, as the EPA's Tier 4 pollution standard kicks in near the end of this decade, the industry may find that these now exotic blends could be the only practical way to meet the law.
"Right now, most folks can't find a way to redesign an engine to meet the particular requirements from a diesel engine."
TO BE CONCLUDED NEXT WEEK...