Tech Briefs
Next-generation power sources

Nissan fuel cell vehicle. Nissan's Li-Ion battery module. Fuel processor system from Epyx. 22 kWe gasoline fuel processor from Epyx.

Every second 21955 L (5800 gal) of petroleum are consumed by the transportation sector in the United States. "Seventy-five percent of that is used by cars and trucks. Petroleum consumption is going up, and has been going up since 1987," says Thomas Gross, Deputy Assistant Secretary in the U.S. Department of Energy's Office of Transportation Technologies, Energy Efficiency and Renewable Energy. Gross and several advanced vehicle industry representatives updated the state of electric vehicles, hybrid electrics, and alternative fuel vehicles during the EnV '99 conference and expo in Ypsilanti, MI—sponsored by ESD/The Engineering Society in cooperation with SAE.

Having a dependence on petroleum, says Gross, "sets up a situation where we're vulnerable to the import market. There's also the environmental (drawback). Fuel that you don't combust means zero emissions, otherwise it's carbon dioxide." Designing, developing, and marketing zero-emission vehicles is not a simple undertaking.

General Motors took six years to develop and market its EV1 electric car. Although considered the most energy-efficient production vehicle available, the EV1 remains a niche attraction. It has evolved since its 1997 introduction. The 1999 model features optional advanced nickel-metal-hydride batteries with an active cooling system, while batteries are being recharged, a cooling fan at rear of vehicle draws air from heat pump.

Generation II EV1's power electronics bay has one-third fewer parts, is half the size, and half the cost of the first version. "We designed EV1 with a long-life body and chassis," says Robert Purcell, GM's Executive Director of Advanced Technology Vehicles.

As EV1's first-issued customer leases expire, the modular-assembled cars are retrofitted with second-generation gear. So far, 70% of leasees have chosen to renew for the second-generation EV1. "We remain committed to electric drive technology because we believe it is fundamental to all classes of advanced vehicles—electrics, hybrids, and fuel cells," says Dr. Lawrence Burns, Vice President, General Motors Research & Development and Planning.

Like GM, Toyota is taking a widespread approach to finding the ultimate eco-friendly vehicle. In North America, Toyota is working on developing cleaner conventional internal combustion gasoline engines, compressed natural gas vehicles, electric vehicles, fuel cell electric vehicles, and hybrid drive systems. (Toyota and GM have partnered to research and develop more than a dozen advanced vehicle and system projects.)

The Toyota Prius, the world's first mass-produced hybrid vehicle, is powered by the Toyota Hybrid System—a gasoline engine and an electric motor. As sold in Japan, Prius has a 1.5-L, 4-cylinder engine with a nickel-metal-hydride battery pack that weighs 97 lb (44 kg) and produces 288 Volts. "The Toyota Hybrid System is not the final solution, but it's a very good intermediate step," says Dave Hermance, Executive Engineer, Environmental Engineering at Toyota Technical Center in California. Prius comes to the U.S. and European market in 2000 with an upgraded power presentation.

Honda brings its gasoline-electric hybrid to the U.S. later this year. Dubbed the Honda VV in its concept stage, the vehicle combines an aluminum body with Honda's Integrated Motor Assist gasoline-electric hybrid system. Fuel economy is projected at 30 km/L (70 mpg), or more than 1127 km (700 miles) on a tank of gasoline.

Nissan is developing a compressed natural gas Frontier 4x4 pickup truck for the U.S. market. The prototype Frontier has a V6, 3.3-L dedicated natural gas engine with an in-bed tank, a mid-ship underbody tank, and an optional in-cab tank. Among Nissan's more ambitious advanced technology efforts is a fuel-cell-powered vehicle targeted for the Japanese market between 2003-2005.

Equipped with an onboard methanol reformer, the fuel cell produces hydrogen through use of a catalyst. A Nissan fuel cell demonstration vehicle uses a neodymium magnet synchronous traction motor (drives the wheels and functions as generator during regenerative braking) combined with lithium-ion batteries. Both technologies are used on the Altra EV (California demonstration fleet), and the Nissan R'nessa EV in Japan. Nissan's forthcoming fuel cell prototype vehicle is expected to increase fuel economy more than 50% compared to a conventional gasoline engine.

Epyx, a technology development company based in Cambridge, MA, has successfully lab-demonstrated reformer/fuel cell technology using California phase II reformulated unleaded gasoline, ethanol, methanol 85, Fischer-Tropsch synthetic fuel, as well as compressed natural gas. "The hook is using today's gasoline. This technology is an onboard process that only produces hydrogen as it's needed to produce energy," says Epyx's Vice President for Engineering, William Mitchell.

Following May's lab experiments, Mitchell says, the technology is ready for real-world vehicle demonstrations. "We're the only company in the world that has demonstrated pump-grade gasoline-onboard reformer technology."

Ford Motor Company's line-up of F-Series Super Duty trucks for the 2000 model year will be available as bi-fuel propane vehicles, while the Ford Excursion sport utility vehicle will be offered in limited numbers as a demonstration dedicated propane version. The automaker now offers 11 alternative fuel cars and light trucks that run on natural gas, propane, ethanol, or electricity in the U.S.

Dodge Caravan and Plymouth Voyager 1999 model year electric minivans use nickel-metal-hydride batteries as a replacement to a lead-acid battery pack. DaimlerChrylser belongs to the California Fuel Cell Partnership, as does the California Air Resources Board, the California Energy Commission, Ballard Power Systems, Ford Motor Company, ARCO, Shell, and Texaco. An expected 50 fuel cell passenger cars and electric buses will be put on the road between 2000 and 2003 through the partnership.

General Motors' EV1 electric car.

NECAR 4, a zero-emission vehicle that uses fuel cell technology to generate electricity, is expected to be real-world tested by DaimlerChrysler as part of the project. (NECAR 4 is a concept based on the Mercedes-Benz A-Class compact car.)

One unresolved stumbling block to widespread consumer acceptance of advanced technology vehicles is cost. "It seems like people want less carbon dioxide emissions for society, but they don't want to pay for a societal benefit," Tom Moore, vice president Liberty and Technical Affairs for DaimlerChrysler, says.