What is a Hydrogen Fuel Cell?
Hydrogen fuel cells were invented in 1839 and have enjoyed a long life of powering scientific and government equipment over the past century. Hydrogen fuel cells powered the Gemini and Apollo space missions and provided power to the Space Shuttle and many smaller vehicles. Hydrogen fuel cell technology has been tested and numerous vehicle manufacturers are bringing commercial fuel cell electric vehicles to market in 2012. Laboratories throughout the country, including Virginia institutions, continue to work to perfect fuel cells for low cost commercial use through improvements in technology.
Like batteries, fuel cells convert chemical energy into electricity. The main difference between the two technologies is that fuel cells use external chemical fuel. For vehicles, hydrogen is commonly stored in tanks that are 20x stronger than regular gas tanks. The main type of fuel cell use catalysts to convert hydrogen to protons and electrons. The electrons travel through a circuit containing an electric load (like an electric motor) and power that circuit before catching up protons, which flow through a membrane in the fuel cell. When the protons and electrons recombine, the byproduct is water.
Hydrogen (H2) is the simplest and lightest fuel, and is in a gaseous state at atmospheric pressure and ambient temperature. Hydrogen may contain low levels of carbon monoxide and carbon dioxide, depending on the source. Hydrogen is being explored for use in combustion engines and fuel cell electric vehicles. On a volumetric basis, the energy density of hydrogen is very low under ambient conditions. This presents greater transportation and storage hurdles than for liquid fuels. Storage systems being developed include compressed hydrogen, liquid hydrogen, and physical or chemical bonding between hydrogen and a storage material (for example, metal hydrides).
The ability to create hydrogen from a variety of resources and its clean-burning properties make it a desirable alternative fuel. Although there is no significant transportation distribution system currently for hydrogen transportation use, we can transport and deliver hydrogen for early market penetration using the established hydrogen infrastructure; for significant market penetration, the infrastructure will need further development.
Hydrogen fuel cells can be built to practically any size, which means that they can power anything from a spacecraft to a truck to a cell phone.
How is Hydrogen for Transportation Fuel Made?
Hydrogen can be produced using diverse, domestic resources including fossil fuels, such as natural gas and coal (with carbon sequestration); nuclear; and biomass and other renewable energy technologies, such as wind, solar, geothermal, and hydro-electric power. One common way to produce hydrogen is through electrolysis, which separates water into hydrogen and oxygen. Researchers are working to develop a wide range of technologies to produce hydrogen economically and in environmentally friendly ways.
What are the Benefits of Using Hydrogen as a Transportation Energy Source?
Expanded use of hydrogen as an energy source in this country could help address concerns about energy security, global climate change, and air quality. Fuel cells are an important enabling technology for the hydrogen future and have the potential to revolutionize the way we power our nation, offering cleaner, more efficient alternatives to the combustion of gasoline and other fossil fuels. Hydrogen’s main benefits are: stronger national security, reduced greenhouse gas emissions, improved air quality, and increased energy efficiency.
What is the Transportation Market for Hydrogen?
The hydrogen market has great potential for transportation applications. At the end of 2008, Hundreds of hydrogen-powered light duty vehicles were on U.S. roads and drove a total of 1,100,000 miles that year. At this time, government and industry are working together to overcome technical and cost barriers. Numerous vehicle manufacturers are advancing vehicles for commercial sale to the general public, including Daimler, Ford, GM/Opel, Honda, Hyundai/Kia, Renault, Nissan, and Toyota.
There are numerous hydrogen fueling stations, both for private and public use. To view all hydrogen stations across the country, go to the AFDC’s Alternative Fuels Station Locator.