Fuel-Cell Cars

Automobile manufacturers have invested heavily in fuel cells. Buses powered by fuel cells are on the road, and prototype cars are being tested. The chances are excellent that there is a fuel-cell car in your future. 

Figure 8.33. Schematic of the efficiencies of a fuel cell driven car and a conventional car with a combustion engine. Note the advantage of the fuel cell car at low load, prevailing under urban driving conditions.

A well-designed hydrogen fuel cell car should be safer than a natural gas or a gasoline car in collisions in open spaces. 

As mentioned earlier, separation of C02 at concentrated sources is easier than from the environment, and carbon capture at upstream decarbonizes many subsequent economic sectors. However, it does require significant changes in the existing infrastructure of power and chemical plants. Furthermore, approximately half of all emissions arise from small, distributed sources. Many of these emitters are vehicles for which onboard capture is not practical. Thus, unless all the existing automobiles are replaced by either hydrogen-powered fuel cell cars or electric cars, the capture of C02 from the air provides another alternative for small mobile emitters. 

Efforts continue to improve fuel cell technology and utilization which should reduce costs. The General Motors fuel cell program aims at having a commercial fuel cell vehicle by 2010. Volume production of fuel cell cars should reduce costs, but one Department of Energy projection with a production of 500,000 vehicles a year still has the cost too high. 

If fuel cell cars run on gasoline, there is minimum disruption, but many predict that methanol will serve as a bridge to direct hydrogen. Early fuel cell cars may run on methanol, but rapid advances in direct-hydrogen storage and production could bypass any liquid fuel phase. 

While the mass production of fuel cell cars is some time away, if cost-competitive fuel cell stacks are available soon, it can change the competitive mix of transportation options. 

DaimlerChrysler renewed its interest in liquid hydrogen, and that was the fuel in NECARIV that appeared in 1999. NECARIV was among the first drivable, zero-emission, fuel cell cars in the United States along with the Ford and GM fuel cell prototypes. It was a major advance over NECAR III, whose cell and reformer took up all the passenger space. NECAR IV was still heavy and slower to accelerate than Ford s P2000 fuel cell car, but it had room for five, with a 40% power increase over the earlier version, a higher top speed of 90 miles per hour and a range of 280 miles. 

A Princeton study of the Los Angeles area focused on the potential for solar photovoltaic plants in the desert areas east of the city. The study concluded that enough hydrogen could be produced with solar power in an area of 21 square miles to fuel one million fuel cell cars. 

There have also been revivals of the steam car. Robert McCulloch, the chain-saw millionaire, spent part of his fortune on a steam prototype, called the Paxton Phoenix, between 1951 and 1954. William Lear of Learjet fame, spent 15 million in 1969 on a turbine bus and a 250-horsepower turbine steam car. Both used quiet, efficient steam engines although the bus had reliability problems and poor gas mileage. Lear also tried to enter a steam car into the 1969 Indianapolis 500. The British firm of Austin-Healey was also working on a steam car in 1969. It had four-wheel drive. However, even prosperous entrepreneurs like McCulloch and Lear found that they lacked the means and support structure to successfully mass market a competitive car. Alternative power systems would have to wait until air-quality regulations resulted in some breakthroughs with hybrid and even fuel-cell cars. 

Individual drive motors on each of the vehicle s four wheels allows a fuel cell powered all wheel drive system. Three tanks hold Hy-wire s hydrogen fuel, compressed at 5,000 pounds per square inch. These were developed by Quantum Fuel Systems, the company that developed the industry s first 10,000-psi tanks, which could allow a fuel cell car to have a driving range of 230 miles. 

The Sequel is almost the size of a Cadillac SRX. It has a 300-mile range on a refueling of hydrogen and accelerates to 60 mph in less then 10 seconds. Other fuel cell cars have a driving range of 170-250 miles and cover 0-60 mph in 12-16 seconds depending on whether they use a battery. 

Ford planned to produce a fuel cell family car based on the aluminum and composite P2000 which is like the Ford Contour but weighs a thousand pounds less. In 1997, Ford announced that its fuel cell car would carry compressed hydrogen, but the fuel storage question may be still open. 

The FCX-V2 used a Honda designed fuel cell and reformer. Downsizing the methanol reformer remained to be done and both test cars had room only for a driver and passenger. Fuel cell components took up the rear seats. The need to test fuel cell cars under real-life conditions is one reason Honda joined DaimlerChrysler in the California Fuel Cell Partnership. More recently Honda announced the first lease of its advanced... 

Toyota has been sharing technology with partner GM on electric, hybrid, and fuel cell cars. In 1998, the research division was testing methanol reformers and metal hydride hydrogen storage and had prototypes of each. 

In Albany, NY, the state government started leasing Honda FCX hydrogen fuel cell cars on a cold November morning. Previous fuel cell vehicle demonstration programs have occurred in warmer areas to ensure that the fuel cell stacks would not freeze up. Subzero temperatures can change any liquid water present into expanding ice crystals that can puncture thin membranes or crack water lines. Honda has demonstrated that their fuel cell units can operate under winter conditions, this was an important achievement for practical fuel cell cars. 

DaimlerChrysler had a fleet of more than 100 F-cell fuel cell cars called the F-Cell which were used for worldwide testing. They have also built 33 fuel cell buses for 10 European cities as well as Beijing and Perth. DaimlerChrysler has invested over 1 billion in hydrogen fuel cell technology. The fuel cell vehicle fleet is powered by Ballard stacks. 

Some computer models of fuel cell cars show the power needed at the wheel which is computed from the weight of the car, energy of the fuel, accessories and other variables including mileage. An onboard reformer has been shown to provide 70 miles per gallon, but compressed hydrogen... 

Ashley, Steven, "On the Road to Fuel Cell Cars," Scientific American, Volume 292 Number 3, March, 2005. 

These fuel cell cars could be used to provide power and even water to buildings where people live or even work. Commuters could drive their cars to work and connect them to a hydrogen line. While they worked, their cars would be producing electricity, which they could then sell back to the grid. The car, instead of just occupying a parking space, would become a profit generator. 

Parked fuel cell cars could be plugged into the grid to generate power. If only a small percentage of drivers used their vehicles as power plants to sell energy back to the grid, many of the power plants in the country could be closed. 

Hydrogen powered internal combustion engines could promote the infrastructure for fuel cell cars. An internal combustion engine (ICE) can... 

A fuel cell car, bus or truck is in essence an electric vehicle powered by a stack of hydrogen fueled cells that operates like a refuelable battery. A battery uses chemical energy from its component parts, while a fuel cell uses an electrochemical process to generate electricity and receives its energy from the hydrogen fuel and oxygen that are supplied to it. Like the plates in a battery, the fuel cell uses an anode and cathode, attached to these are wires for the flow of current. These two electrodes are thin and porous. 

The emergence of commercial fuel cell cars will depend on developments in membrane technology, which are about one third of the fuel cell cost. Improvements are desired in fuel crossover from one side of a membrane to the other, the chemical and mechanical stability of the membrane, undesirable side reactions, contamination from fuel impurities and overall costs. 

The hydrocarbon membrane can also operate at higher temperatures, of up to 95°C, which allows the use of smaller radiators to dissipate heat. It also lasts 50% longer, while generating up to 15% more power and operating at lower humidity levels. Fluorocarbon membranes can cost about 300 per square meter, the PolyFuel materials cost about half of this. While hydrocarbon membranes may have to prove themselves to many, Honda s FCX fuel cell cars use them. 

A hydrogen-based economy could be the ideal scenario for personal transportation. The ultimate goal is a fuel cell car that is competitive in price and performance with the internal combustion vehicle. Some early users will pay a premium for new technology, but most drivers will not pay 20-30% more for similar performance. 

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