The hydrogen atom is composed of one proton and one electron, making it the lightest element in the universe. It is also the most abundant element in the universe, making up more than 90% of all known matter. The abundance of hydrogen on earth, minimal environmental consequences of its use and the need to replace fossil fuels, makes it the ideal fuel of the future.
Hydrogen is not an energy source. It is an energy carrier like electricity. On earth, hydrogen is found combined with other elements. For example, in water hydrogen is combined with oxygen. In fossil fuels and many organic compounds, it is combined with carbon as in petroleum, natural gas, coal or biomass. This is the technological challenge facing researchers: to separate hydrogen from other naturally occurring compounds in an efficient and economic process.
The production of hydrogen requires utilizing one of the primary energy sources – solar-based, fossil fuels or nuclear. Once hydrogen is produced, it can be reacted with oxygen in a manner similar to gasoline combustion in an engine or used in a fuel cell to generate electric power. The electricity produced by a fuel cell can then be used to power electrical devices such as computers or an electric car. An important benefit is that, using hydrogen does not produce carbon monoxide or carbon dioxide. This makes it attractive because no greenhouse gases are produced.
Since the 1970s, NASA has used fuel cells to power the space shuttle’s electrical systems and to provide water for astronauts to drink.
Another challenge to a hydrogen vision is its storage after it is produced. Storing enough hydrogen energy in comparable weights, volumes and vehicle range to gasoline is a significant technological challenge hindering its wide-scale adoption. In order to store hydrogen in a more compact space, it must be stored either as a high-pressure gas, a liquid, or combined with other compounds in a solid form. Each of these storage methods has its limitations and none meets automotive manufacturers requirements as of yet. As a result, extensive research is being conducted on a variety of storage options. The U.S. Department of Energy has declared storage as the most critical technological challenge to the wide-scale adoption of a hydrogen economy.
The production and storage of hydrogen are major research efforts with activities in progress at the Florida Solar Energy Center, other universities, industry and government laboratories around the world. Explore this site to find out more about these issues and some of the solutions being developed.
For further information, see the Hydrogen Q&A or the U.S. Department of Energy's hydrogen basics at http://www.eere.energy.gov/RE/hydrogen_basics.htm.