In response to growing concern over air pollution and our nation's reliance on imported oil, the U.S. Department of Energy has been working with automakers and industry partners to develop vehicle technologies that are virtually pollution free and powered by abundant, renewable, domestic resources. One such promising transportation technology is the fuel cell vehicle.

What Is a Fuel Cell?
A fuel cell produces electricity directly from the reaction between hydrogen (derived from a hydrogen-containing fuel or produced from the electrolysis of water) and oxygen from the air. Like an internal combustion engine in a conventional car, it turns fuel into power by causing it to release energy. In an internal combustion engine, the fuel burns in tiny explosions that push the pistons up and down. When the fuel burns, it is being oxidized. In other words, the fuel combines with oxygen and, as a result, produces energy in the form of heat and mechanical motion. In a fuel cell, the fuel is also oxidized, but the resulting energy takes the form of electricity. What's more, when powered by pure hydrogen, the only by-products of the reaction are heat and water.

A fuel cell power system has many components, but its heart is the fuel cell stack, which is made of many thin, flat cells layered together. (Although the term fuel cell is often used to describe the entire stack, strictly speaking, it refers only to the individual cells.) Each cell produces electricity, and the output of all the cells is combined to power the vehicle.

Fuel Cell Vehicle Availability
There are currently no fuel cell vehicles available for sale in the United States. There are, however, many types of fuel cell vehicles in demonstration. These include light-duty vehicles by most major auto manufacturers, medium-duty vehicles, and buses. See our Fuel Cell Applications page for more details.

Cost
It is too early to estimate the cost of the first retail fuel cell vehicles. Incentives and rebates may be necessary to help reduce the initial purchase price of these vehicles.

Operational Performance
Fuel cell vehicles are being developed to meet the performance expectations of today's consumers. These vehicles are expected to be extremely quiet and have very little vibration.

Maintenance Considerations
Because fuel cell vehicles are still in the prototype stage, maintenance and reliability data are unavailable.

Safety
The goal is to develop fuel cell vehicles with levels of safety and comfort that are comparable to those of conventional vehicles. If used, high-pressure hydrogen tanks will be designed for maximum safety to avoid rupture. Additionally, manufacturers are perfecting sensors that will immediately detect impact in the case of collision and additional sensors that will detect any leakage from the hydrogen tanks. In both cases, the sensors will instantly shut the valves on the tanks.

Benefits
Using pure hydrogen to power fuel cell vehicles offers the distinct advantage of zero emissions, but only on the vehicle, not at the hydrogen production source. However, emissions created at a single point of production are often easier to control than those produced by a moving vehicle. A fuel cell vehicle that runs on pure hydrogen produces only water vapor—using any other fuel will produce some carbon dioxide and other emissions, but far less than what is produced by a conventional vehicle.

Fuel cell vehicles are expected to achieve overall energy conversion throughput efficiencies around twice that of today's typical gasoline internal combustion engines. The fuel cell system is being targeted by DOE to achieve 60% efficiency by 2010. Fuel cell vehicles can run on any hydrogen-rich liquid or gas, as long as it is suitably processed. Gasoline is one possibility, but in addition to pure hydrogen, alternative fuels such as ethanol, methanol, natural gas, and propane can also be used.

Hydrogen is the most abundant element in the universe and can be found on Earth in virtually unlimited quantities. Using hydrogen or other domestically produced alternative fuels to power fuel cell vehicles will help reduce our nation's dependence on imported oil. Dept. of Energy