Detroit--The movement to wean our transportation system off its dependence on hydrocarbon fuels--and foreign sources of supply--has seen several milestones in hydrogen powered vehicle development this summer.
Last month at the 14th World Hydrogen Energy Conference in Montreal, BMW showed its fifth-generation hydrogen-burning internal combustion engine (ICE) car, the 745h. The company's first such powered vehicle took to the test track in 1979. The V8 engine burns both gasoline and hydrogen to make up for the dearth of hydrogen filling stations. Franz-Josef Wetzel, head of BMW Future Powertrain Technology says an ICE was chosen because it is more efficient than fuel cells at delivering power at levels more than 100 kW (134 hp). The 745h engine produces 181 hp, but if optimized for high-compressing burning solely on hydrogen, with its 110 octane equivalency, 30% greater power and torque is produced. The company plans on producing the car, which features liquid hydrogen storage, in two to four years. (For in-depth details and an issues discussion, see the August 5, 2002 issue of Design News.)
Also on hand in Montreal was the latest prototype of the Ford Focus Fuel Cell Vehicle (FCV). The car is a gaseous-hydrogen fuel cell/battery "hybrid" that the company will begin building in low-volume in 2004, according to John Wallace, executive director of Ford's environmental TH!NK Group. A 300V Sanyo battery boosts acceleration but cannot entirely power the vehicle. A Ballard Energy Systems 85-kW fuel-cell stack is the primary power source. Other features include an electrohydraulic regenerative brake-by-wire system, an integrated powertrain combining the traction inverter module and electric-motor transaxle, and a 5,000 psi tank for hydrogen storage.
Last week, Honda announced its four-passenger fuel-cell car, the FCX, was the first such automobile to receive U.S. EPA and California state certification as a National Low Emission Vehicle (NLEV) and Zero Emission Vehicle (ZEV), respectively. Later this year, the company will start leasing 30 FCXs, split between California and the Tokyo area, for two to three years. While the company is not committing to mass sales of the car, "We'll have an opportunity to evaluate fuel cell vehicles in real world applications and to study the development of a refueling infrastructure," according to Tom Elliot, American Honda executive VP. The FCX holds 157 liters of gaseous hydrogen pressurized to 5,000 psi. This fuel feeds a Ballard Power Systems fuel cell stack capable of putting out 78 kW. The 60 kW/201 lb-ft ac synchronous motor can accelerate the subcompact to 93 mph. Range is 220 miles.
Perhaps the most intriguing hydrogen-power news of the season is yet to come. Ford and Ballard, which also makes electric drives, are set to make a joint announcement on August 7, said to involve hydrogen ICE hybrid development.
When one says hydrogen for transportation, safety issues come to the fore, particularly leakage and accident concerns. Developers like to show how their tanks withstand all kinds of impacts. Christoph Huss, BMW senior VP for Science and Traffic Policy says, there is a risk, a different risk, but not a greater risk than with gasoline. "With hydrogen, if there is a leak it disappears up into the atmosphere, with gasoline, vapor collects under the car," he notes.
Ideally, hydrogen for these vehicles will be produced from renewable resources in the future, such as wind, hydro, solar, and nuclear power, rather than reformulated from natural gas or gasoline. Thus well-to-wheels emissions would be minimized.
To find out more, visit www.bmw.com/cleanenergy and www.ballard.com.