GM Unveils Next Millenium Fuel Cell Vehicle
January 11, 2000 - DETROIT -- General Motors today unveiled a fuel cell-powered version of its Precept high-efficiency concept vehicle featuring a hydride hydrogen storage system that could deliver up to 500 miles range. The fuel cell-powered Precept -- shown for the first time during the 2000 North American International Auto Show -- was developed by two GM units, Advanced Technology Vehicles and the Global Alternative Propulsion Center.
The Precept fuel cell electric vehicle (FCEV) represents a high-tech, future look at what General Motors believes will be the long-term propulsion system for super-efficient, practical vehicles in the next millenium.
The Precept FCEV is the merger of General Motors' two advanced technology development streams -- GM's Precept, the world's most energy efficient vehicle platform and GM's fuel cell engine, an ultra efficient means to generate electricity for vehicle propulsion. The combined result is a breakthrough concept vehicle fueled by hydrogen that offers unparalleled efficiency.
"We believe hydrogen will be the fuel of the future," said Larry Burns, GM's vice president in charge of research and development and global portfolios. "Fuel cell technology has the potential to best utilize hydrogen as the fuel for propulsion. Our goal is to pursue hydrogen as part of GM's portfolio of options and ultimately remove from the environmental debate concerns about automotive emissions and fuel economy."
Fuel cells use continuous electrochemical reactions to convert chemicals into direct electrical current. In principle, they operate like a battery in which the active ingredients -- in this case hydrogen and oxygen -- are supplied continuously to the cell instead of stored. Fuel cells are ideal energy conversion devices because they have no moving parts and their byproducts -- heat and water vapor -- pose no harm to the environment.
Electricity for the vehicle's electric drive system is provided by a 400 cell 100 kW PEM fuel cell stack operating at 260 to 340 volts. The GM designed and built fuel cell stack delivers world class power densities in a very compact design, in excess of 1.0 kW per liter and 1.0 kW per kilogram. The stack was developed to operate at low pressures of hydrogen and air, which enabled the use of a quiet and low power air compressor. The stack can start and operate over the ambient temperature range required of modern vehicles.
The oxygen required to operate the fuel cell stack comes from air. The hydrogen is stored on board the vehicle in "solid material" at relatively low temperature and pressure. GM's hydrogen tank contains a specially formulated "chemical hydride" material. The chemical hydride is engineered to release its stored hydrogen in a very efficient manner and at the same temperature the fuel cell stack operates, enabling nearly twice the driving range compared to a similar size gasoline tank. Battery powered electric heat delivered to a small section of the tank provides for fast starts. The combination of quick start and fast hydrogen chemical hydride release provides good vehicle acceleration.
Hydrogen is produced off-board the vehicle by a variety of means which are best matched to the primary energy sources available in each market area. Hydrogen is delivered to the vehicle through a special nozzle and inlet. The nozzle and vehicle inlet operate as a system providing mechanical, electrical and electronic safety interlocks and enable fast refueling in five minutes, typically.
"The Precept FCEV is a five-passenger family sedan concept that could deliver better than 100 miles per gallon fuel economy performance (gasoline equivalent fuel economy), just over nine seconds 0-60 mph acceleration, and 500 miles range," said Byron McCormick, co-executive director of GM's Global Alternative Propulsion Center. "It's a 'no excuses' vehicle featuring excellent driving performance, comfort and convenience features, and zero emissions. And all of this with no compromises in driving safety, crashworthiness and safe refueling."
Fuel cells were originally developed for the U.S. Space Program and provide power for today's space shuttles. Fuel cell technology is not new to General Motors. GM first conducted fuel cell testing in 1964 and produced the auto industry's first operational fuel cell-powered electric vehicle in 1968. McCormick said the U.S. government deserves credit for many of the advancements in fuel cell technology.
"We're appreciative of the efforts of the U.S. Department of Energy and of PNGV
to help move fuel cell technology out of aerospace and into industry," he said.
"At GM, we've accelerated the pace of fuel cell research and development to the
point that it feels like we're in the computer industry, where the product arriving
at retailers is virtually obsolete before it goes on sale. For example, we're currently
developing our 10th generation fuel-cell stack design, with a new design implemented
nearly every two months."
General Motors has achieved tremendous improvements
in fuel cell technology technical performance. Recent efforts have been concentrated
on solving practical problems associated with fuel cell use in everyday automobiles
such as below freezing temperatures. Scientists and engineers at GM's Global Alternative
Propulsion Center recently demonstrated repeated freeze and quick start-up performance
of GM fuel cell stacks down to -20°C.
GM's collaborations with automotive companies, such as Toyota, and with energy companies also are helping to speed the development process and to reduce technical risks. In early 1999 GM signed a five-year technical agreement with Toyota to speed the development and introduction of advanced vehicle technologies, including in the areas electric, hybrid electric and fuel cell electric vehicles.
Other hurdles leading to hydrogen powered vehicles include storage and transportation on-board the vehicle, the perceived safety and its cost. Present hydrogen storage technologies have deficiencies in either size, weight, performance or cost. These technologies, as they exist today, would not meet the expectations of the millions of customers GM would like to attract with a mass-market fuel cell car. A transition fuel such as an improved gasoline or other liquid hydrocarbon based fuel may be required for the near term to take advantage of the existing refueling infrastructure. An on-board fuel processor would be used to make hydrogen from the liquid fuel. Solving these issues is precisely what GM's collaborations are all about.
"GM has already demonstrated the fuel cell's technical feasibility", according to McCormick. "Fuel cell-powered vehicles need to be acceptable to customers around the world, and our focus is the to overcome the remaining obstacles of affordability and fuel availability. Our long-range view is to get beyond the need for on-board fuel processors and fuel directly with hydrogen.
The fuel-cell-powered Precept FCEV concept car is GM's vision of what a commercially viable fuel cell cars can be, in terms of its design, its propulsion system, and its performance. It's a glimpse into a future that may be closer than most people think.