In 2003, President George W. Bush announced the Hydrogen Fuel Initiative to accelerate the research and development of hydrogen, fuel cell and infrastructure technologies that would enable hydrogen fuel cell vehicles to reach the commercial market in the 2020 timeframe. The widespread use of hydrogen can reduce our dependence on imported oil and benefit the environment by reducing greenhouse gas emissions and criteria pollutant emissions that affect our air quality. This book examines hydrogen, which holds the potential to provide clean, safe, affordable and secure energy from abundant domestic resources and could decrease our dependence on foreign sources of oil.